Lee SH


Full name : Lee Si Hyeock

First name : Si Hyeock

Mail : Research Institute for Agriculture and Life Sciences, Seoul National University, 599 Gwanakno, Gwanakgu, Seoul 151-742

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Country : Korea

Email : shlee22@snu.ac.kr

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References (120)

Title : Balance-directed protein engineering of IsPETase enhances both PET hydrolysis activity and thermostability - Lee_2023_bioRxiv__
Author(s) : Lee SH , Seo H , Hong H , Park J , Ki D , Kim M , Kim HJ , Kim KJ
Ref : Biorxiv , : , 2023
Abstract : A mesophilic PETase from Ideonella sakaiensis (IsPETase) has been shown to exhibit high PET hydrolysis activity, but its low thermostability limits its industrial applications. We herein developed an engineering strategy for IsPETase to enhance PET hydrolysis activity, thermostability, and protein folding of the enzyme. Balance-directed Z1-PETase variant outperforms the stability-directed Z2-PETase variant under both mesophilic and thermophilic conditions, although Z2-PETase exhibits higher thermostability than Z1-PETase. The Z1-PETase is also superior to Fast-PETase, Dura-PETase, and LC-CICCG in terms of depolymerization rate regardless of temperature conditions we tested. Thus, maintaining a balance between PET hydrolysis activity and thermostability is essential for the developmentof high-performance PET hydrolases. In a pH-stat bioreactor, Z1-PETase depolymerized >90% of both transparent and colored post-consumer PET powders within 24 and 8 hours at 40C and 55C, respectively, demonstrating that the balance-directed IsPETase variant produced herein may be applicable in the bio-recycling of PET.
ESTHER : Lee_2023_bioRxiv__
PubMedSearch : Lee_2023_bioRxiv__
Gene_locus related to this paper: idesa-peth

Title : Three-directional engineering of IsPETase with enhanced protein yield, activity, and durability - Lee_2023_J.Hazard.Mater_459_132297
Author(s) : Lee SH , Seo H , Hong H , Park J , Ki D , Kim M , Kim HJ , Kim KJ
Ref : J Hazard Mater , 459 :132297 , 2023
Abstract : The mesophilic PETase from Ideonella sakaiensis (IsPETase) has been shown to exhibit high PET hydrolysis activity, but its low stability limits its industrial applications. Here, we developed a variant, Z1-PETase, with enhanced soluble protein yield and durability while maintaining or improving activity at lower temperatures. The selected Z1-PETase not only exhibited a 20-fold improvement in soluble protein yield compared to the previously engineered IsPETase(S121E/D186H/S242T/N246D) (4p) variant, but also demonstrated a 30% increase in low-temperature activity at 40 degreesC, along with an 11 degreesC increase in its Tm(D) value. The PET depolymerization test across a temperature range low to high (30-70 degreesC) confirmed that Z1-PETase exhibits high accessibility of mesophilic PET hydrolase and rapid depolymerizing rate at higher temperature in accordance with the thermal behaviors of polymer and enzyme. Additionally, structural interpretation indicated that the stabilization of specific active site loops in Z1-PETase contributes to enhanced thermostability without adversely impacting enzymatic activity. In a pH-stat bioreactor, Z1-PETase depolymerized > 90% of both transparent and colored post-consumer PET powders within 24 and 8 h at 40 degreesC and 55 degreesC, respectively, demonstrating that the utility of this IsPETase variant in the bio-recycling of PET.
ESTHER : Lee_2023_J.Hazard.Mater_459_132297
PubMedSearch : Lee_2023_J.Hazard.Mater_459_132297
PubMedID: 37595467
Gene_locus related to this paper: idesa-peth

Title : Molecular, biochemical, and toxicological characterization of two acetylcholinesterases from the Western flower thrips, Frankliniella occidentalis - Lee_2023_Pestic.Biochem.Physiol_196_105629
Author(s) : Lee JH , Jeong IH , Lee DW , Lee SH , Yoon KA
Ref : Pestic Biochem Physiol , 196 :105629 , 2023
Abstract : We investigated the molecular and biochemical properties of two acetylcholinesterases (FoAChE1 and FoAChE2) from the Western flower thrips, Frankliniella occidentalis. Polyacrylamide gel electrophoresis and western blotting confirmed the membrane-anchored nature of both FoAChE1 and FoAChE2, which was further supported by hydrophobicity and glycophosphatidylinositol anchor predictions. High expression levels of both enzymes were observed in the head, indicating their predominant distribution in neuronal tissues. FoAChE1 exhibited significantly higher expression levels in all examined tissues compared to FoAChE2, suggesting its major role as a synaptic enzyme. Nonetheless, both recombinant enzymes displayed robust catalytic activity toward acetylthiocholine iodide, and FoAChE1 demonstrated nearly identical catalytic efficiency compared to FoAChE2. FoAChE1 exhibited slightly lower sensitivities to the cholinesterase inhibitors tested, including organophosphates (OPs) and carbamates (CBs), compared to FoAChE2. Field populations of F. occidentalis exhibited polymorphism of alanine vs. serine at position 197 of FoAChE1 within the conserved oxyanion hole. Contrary to common belief, however, functional analysis using recombinant enzymes revealed that neither A197 nor S197 residue was associated with FoAChE1 insensitivity to OPs and CBs. FoAChE2 did not exhibit any polymorphic amino acid substitutions at the positions known to be associated with resistance. Due to the absence of apparent resistance-associated mutations in field populations of F. occidentalis, the judicious use of some OPs or CBs can be suggested for controlling the highly resistant populations to other insecticides. Overall, our findings highlight the significance of both FoAChE1 and FoAChE2 as targets for toxicity assessment, while the specific contribution of each enzyme to toxicity remains unclear.
ESTHER : Lee_2023_Pestic.Biochem.Physiol_196_105629
PubMedSearch : Lee_2023_Pestic.Biochem.Physiol_196_105629
PubMedID: 37945233
Gene_locus related to this paper: fraoc-ACHE1

Title : Carboxylesterase-overexpressing hTERT-immortalized human adipose stem cells in prostate tumor growth inhibition by irinotecan - Kim_2023_J.Cancer.Res.Ther_19_1731
Author(s) : Kim JH , Oh E , Song ES , Yun CW , Lee SH , Song YS
Ref : J Cancer Research Ther , 19 :1731 , 2023
Abstract : INTRODUCTION: Effective chemotherapy has not yet to be developed for castration-resistant prostate cancer (CRPC). Cell-mediated enzyme prodrug therapy (EPT), including a combination of carboxylesterase (CE) and irinotecan (CPT-11), could be a possible treatment option. This study explored a cell-mediated EPT, including a combination of CE and irinotecan (CPT-11), to inhibit CRPC tumor growth using rabbit CE-overexpressing human TERT-immortalized adipose-derived stem cells (hTERT-ADSC.CE). MATERIALS AND METHODS: An hTERT ADSC.CE cell line was established by transfection with a lentiviral vector (CLV-Ubic) encoding the rabbit CE gene. To determine the in vitro suicide effects of hTERT-ADSC.CE, cell cultures were performed using various concentrations of CPT-11 (0.01-5 microM), and to determine the in vitro cytotoxic effects of hTERT-ADSC.CE cells, PC3 and hTERT-ADSC.CE cells were co-cultured. For the in vivo model, PC3 cells (1 x 106 cells) were injected subcutaneously into the flanks of nude mice and hTERT-ADSC.CE cells were injected via an intracardiac route, followed by the continuous treatment using CPT-11 for 2 weeks. The final change in tumor volume was measured and immunohistochemical analysis was performed. RESULTS: The directional and selective migration of hTERT-ADSC.CE cells toward PC3 cells was significantly stimulated by PC3 cells in vitro. The number of apoptotic PC3 cells significantly increased in the presence of hTERT-ADSC.CE and CPT-11 compared to CPT-11 alone. In the in vivo study, the inhibitory effects of hTERT-ADSC.CE combined with CPT-11 were higher than those of CPT-11 monotherapy. After treatment with CPT-11 alone or ADSC.CE in combination with CPT-11, the removed tumor tissues showed hyperchromatic nuclei and apoptotic bodies. CE-overexpressing ADSCs potentiated the inhibition of tumor growth in CRPC-bearing mice in the presence of CPT-11 prodrugs. CONCLUSIONS: This report suggests that cell-mediated EPT including CE and CPT-11 may be efficacious in treating CRPC.
ESTHER : Kim_2023_J.Cancer.Res.Ther_19_1731
PubMedSearch : Kim_2023_J.Cancer.Res.Ther_19_1731
PubMedID: 38376272

Title : Revealing the key gene involved in bioplastic degradation from superior bioplastic degrader Bacillus sp. JY35 - Kim_2023_Int.J.Biol.Macromol_244_125298
Author(s) : Kim SH , Cho JY , Nara S , Hwang JH , Kim HJ , Oh SJ , Bhatia SK , Yun J , Lee SH , Yang YH
Ref : Int J Biol Macromol , 244 :125298 , 2023
Abstract : The use of bioplastics, which can alleviate environmental pollution caused by non-degradable bioplastics, has received attention. As there are many types of bioplastics, method that can treat them simultaneously is important. Therefore, Bacillus sp. JY35 which can degrade different types of bioplastics, was screened in previous study. Most types of bioplastics, such as polyhydroxybutyrate (PHB), (P(3HB-co-4HB)), poly(butylene adipate-co-terephthalate) (PBAT), polybutylene succinate (PBS), and polycaprolactone (PCL), can be degraded by esterase family enzymes. To identify the genes that are involved in bioplastic degradation, analysis with whole-genome sequencing was performed. Among the many esterase enzymes, three carboxylesterase and one triacylglycerol lipase were identified and selected based on previous studies. Esterase activity using p-nitrophenyl substrates was measured, and the supernatant of JY35_02679 showed strong emulsion clarification activity compared with others. In addition, when recombinant E. coli was applied to the clear zone test, only the JY35_02679 gene showed activity in the clear zone test with bioplastic containing solid cultures. Further quantitative analysis showed 100 % PCL degradation at 7 days and 45.7 % PBS degradation at 10 days. We identified a gene encoding a bioplastic-degrading enzyme in Bacillus sp. JY35 and successfully expressed the gene in heterologous E. coli, which secreted esterases with broad specificity.
ESTHER : Kim_2023_Int.J.Biol.Macromol_244_125298
PubMedSearch : Kim_2023_Int.J.Biol.Macromol_244_125298
PubMedID: 37315675
Gene_locus related to this paper: bacpu-q6rsn0

Title : Molecular mechanism underlying high-affinity terephthalate binding and conformational change of TBP from Ideonella sakaiensis - Lee_2023_Int.J.Biol.Macromol_243_125252
Author(s) : Lee SH , Seo H , Hong H , Kim M , Kim KJ
Ref : Int J Biol Macromol , 243 :125252 , 2023
Abstract : Ideonella sakaiensis is the bacterium that can survive by degrading polyethylene terephthalate (PET) plastic, and terephthalic acid (TPA) binding protein (IsTBP) is an essential periplasmic protein for uptake of TPA into the cytosol for complete degradation of PET. Here, we demonstrated that IsTBP has remarkably high specificity for TPA among 33 monophenolic compounds and two 1,6-dicarboxylic acids tested. Structural comparisons with 6-carboxylic acid binding protein (RpAdpC) and TBP from Comamonas sp. E6 (CsTphC) revealed the key structural features that contribute to high TPA specificity and affinity of IsTBP. We also elucidated the molecular mechanism underlying the conformational change upon TPA binding. In addition, we developed the IsTBP variant with enhanced TPA sensitivity, which can be expanded for the use of TBP as a biosensor for PET degradation.
ESTHER : Lee_2023_Int.J.Biol.Macromol_243_125252
PubMedSearch : Lee_2023_Int.J.Biol.Macromol_243_125252
PubMedID: 37295700

Title : Acetylcholine titre regulation by non-neuronal acetylcholinesterase 1 and its putative roles in honey bee physiology - Kim_2023_Insect.Mol.Biol__
Author(s) : Kim S , Seong KM , Lee SH
Ref : Insect Molecular Biology , : , 2023
Abstract : Similar to other insects, honey bees have two acetylcholinesterases (AChEs), AmAChE1 and AmAChE2. The primary catalytic enzyme for acetylcholine (ACh) hydrolysis in synapses is AmAChE2, which is predominantly expressed in neuronal tissues, whereas AmAChE1 is expressed in both neuronal and non-neuronal tissues, with limited catalytic activity. Unlike constitutively expressed AmAChE2, AmAChE1 expression is induced under stressful conditions such as heat shock and brood rearing suppression, but its role in regulating ACh titre remains unclear. In this paper, to elucidate the role of AmAChE1, the expression of AmAChE1 was suppressed via RNA interference (RNAi) in AmAChE1-induced worker bees. The ACh titre measurement following RNAi revealed that the expression of AmAChE1 downregulated the overall ACh titre in all tissues examined without altering AmAChE2 expression. Transcriptome analysis showed that AmAChE1 knockdown upregulated protein biosynthesis, cell respiration, and thermogenesis in the head. These findings suggest that AmAChE1 is involved in decreasing neuronal activity, enhancing energy conservation, and potentially extending longevity under stressful conditions via ACh titre regulation.
ESTHER : Kim_2023_Insect.Mol.Biol__
PubMedSearch : Kim_2023_Insect.Mol.Biol__
PubMedID: 37130064
Gene_locus related to this paper: apime-ACHE , apime-ACHE1

Title : Chrysanthemum coronarium L. Extract Attenuates Homocysteine-Induced Vascular Inflammation in Vascular Smooth Muscle Cells - Lee_2023_J.Med.Food__
Author(s) : Lee AS , Kim Y , Hur HJ , Lee SH , Sung MJ
Ref : J Med Food , : , 2023
Abstract : Hyperhomocysteinemia is a main risk factor for phenotypic modulation of vascular smooth muscle cells (VSMCs) and atherosclerosis. Phenotypic switching and proliferation of VSMCs are related to the progression of vascular inflammation. Chrysanthemum coronarium L. is a leafy vegetable with various biological functions, such as antioxidative, anti-inflammatory, and antiproliferative effects. In this study, we aimed to identify the mechanisms underlying the therapeutic and preventive effects of C. coronarium L. extract (CC) in regulating homocysteine (Hcy)-induced vascular inflammation in human aortic VSMCs. CC did not exhibit cytotoxicity and inhibited Hcy-stimulated VSMC proliferation and migration. In addition, CC promoted Hcy-induced expression of VSMC contractile phenotype proteins, including alpha-smooth muscle actin, calponin, and smooth muscle 22alpha. CC also decreased Hcy-induced accumulation of reactive oxygen species and expression of inflammatory markers nicotinamide adenine dinucleotide phosphate oxidase-4 and soluble epoxide hydrolase. These results showed that CC attenuates Hcy-induced inflammatory responses, highlighting its potential as a therapeutic or preventive target for Hcy-induced vascular inflammation.
ESTHER : Lee_2023_J.Med.Food__
PubMedSearch : Lee_2023_J.Med.Food__
PubMedID: 38010869

Title : Soluble epoxide hydrolase inhibitor, TPPU, attenuates progression of atherosclerotic lesions and vascular smooth muscle cell phenotypic switching - Kim_2022_Vascul.Pharmacol__107086
Author(s) : Kim SA , Lee AS , Lee HB , Hur HJ , Lee SH , Sung MJ
Ref : Vascul Pharmacol , :107086 , 2022
Abstract : Atherosclerosis manifests as a chronic inflammation resulting from multiple interactions between circulating factors and various cell types in blood vessel walls. Growing evidence shows that phenotypic switching and proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the progression of atherosclerosis. Soluble epoxide hydrolase (sEH)/epoxyeicosatrienoic acids are mediated by vascular inflammation. N-[1-(1-oxopropyl)-4-piperidinyl]-N'-[4-(trifluoromethoxy)phenyl]-urea (TPPU) is an sEH inhibitor. This study investigated the therapeutic effect of TPPU on atherosclerosis in vivo and homocysteine-induced vascular inflammation in vitro and explored their molecular mechanisms. We found that TPPU decreased WD-induced atherosclerotic plaque lesions, inflammation, expression of sEH, and nicotinamide adenine dinucleotide phosphate oxidase-4 (Nox4), and increased the expression of contractile phenotype marker of aortas in ApoE (-/-) mice. TPPU also inhibited homocysteine-stimulated VSMC proliferation, migration, and phenotypic switching, and reduced Nox4 in human-aorta-VSMC regulation. We conclude that TPPU has anti-atherosclerotic effects, potentially because of the suppression of VSMC phenotype switching. Thus, TPPU could be a potential therapeutic target for phenotypic switching attenuation in atherosclerosis.
ESTHER : Kim_2022_Vascul.Pharmacol__107086
PubMedSearch : Kim_2022_Vascul.Pharmacol__107086
PubMedID: 35752378

Title : Efficient Production of Naringin Acetate with Different Acyl Donors via Enzymatic Transesterification by Lipases - Baek_2022_Int.J.Environ.Res.Public.Health_19_
Author(s) : Baek Y , Lee S , Son J , Lee T , Oh JM , Lee SH , Kim HU , Seo SW , Park SJ , Yoo HY , Park C
Ref : Int J Environ Research Public Health , 19 : , 2022
Abstract : Naringin, one of the citrus flavonoids and known as a natural antioxidant, has limited bioavailability owing to its low stability and solubility. However, naringin esters formed via acylation have recently been reported to possess improved physical and chemical properties. The development of these compounds has a great potential in the food, cosmetic and pharmaceutical industries, but low conversion and productivity are barriers to industrial applications. This study aimed to improve the conversion of naringin acetate, which is formed via the enzymatic reaction between naringin and an acyl donor. An optimal reaction condition was determined by evaluating the effect of various variables (enzyme type, enzyme concentration, acyl donor, molar ratio of reactants, reaction temperature, and solvent) on the synthesis of naringin acetate. The optimal condition was as follows: 3 g/L of Lipozyme TL IM, molar ratio of 1:5 (naringin:acyl donor), reaction temperature of 40 degreesC, and acetonitrile as the reaction solvent. Under this condition, the maximum conversion to naringin acetate from acetic anhydride and vinyl acetate was achieved at approximately 98.5% (8 h) and 97.5% (24 h), respectively. Compared to the previously reported values, a high conversion was achieved within a short time, confirming the commercial potential of the process.
ESTHER : Baek_2022_Int.J.Environ.Res.Public.Health_19_
PubMedSearch : Baek_2022_Int.J.Environ.Res.Public.Health_19_
PubMedID: 35270665

Title : Characterization of molecular and kinetic properties of two acetylcholinesterases from the Colorado potato beetle, Leptinotarsa decemlineata - Yoon_2022_Pestic.Biochem.Physiol_185_105137
Author(s) : Yoon KA , Kim JH , Nauen R , Alyokhin A , Clark JM , Lee SH
Ref : Pestic Biochem Physiol , 185 :105137 , 2022
Abstract : The molecular and biochemical properties of two acetylcholinesterases (LdAChE1 and LdAChE2) from the Colorado potato beetle, Leptinotarsa decemlineata, were investigated in this study. Polyacrylamide gel electrophoresis in conjunction with western blotting with LdAChE1- or LdAChE2-specific antibodies suggested that LdAChE1 exists in a soluble form, whereas LdAChE2 exists in both soluble and amphiphilic forms with a glycophosphatidylinositol anchor. Both LdAChEs exist as homodimers with each monomer connected with a disulfide bond. LdAChE1 was the most highly expressed in the thorax followed by the head, leg, and abdomen, whereas LdAChE2 was the most highly expressed in the head, followed by the thorax, leg, and abdomen. The overall expression levels of LdAChE1, however, were higher than those of LdAChE2 in all examined tissues. Kinetic analysis using recombinant LdAChE1 and LdAChE2 showed that LdAChE2 has a 4.8-fold higher catalytic efficiency toward acetylthiocholine iodide compared to LdAChE1. LdAChE2 was more sensitive to organophosphorus and carbamate insecticides than LdAChE1. The addition of irreversibly phosphorylated LdAChE1 via paraoxon titration significantly reduced LdAChE2 inhibition by insecticides and glycoalkaloids, suggesting a sequestration role of soluble LdAChE1 in the chemical defense against xenobiotics. Taken together, LdAChE2 may be the main enzyme for synaptic transmission, thus serving as a toxicologically more relevant target, whereas the soluble LdAChE1 may function as a bioscavenger.
ESTHER : Yoon_2022_Pestic.Biochem.Physiol_185_105137
PubMedSearch : Yoon_2022_Pestic.Biochem.Physiol_185_105137
PubMedID: 35772844
Gene_locus related to this paper: lepde-ACHE , lepde-ACHE1

Title : Toxicological and molecular adverse effect of Illicium verum fruit constituents toward Bradysia procera - Hong_2022_Pest.Manag.Sci__
Author(s) : Hong TK , Lee SH , Shin JS , Jang KH , Na ES , Park CS , Kim CH , Kim JR , Balusamy SR , Perumalsamy H
Ref : Pest Manag Sci , : , 2022
Abstract : BACKGROUND: Bradysia procera, a ginseng stem fungus gnat, is one of the most serious insect pests of Korea ginseng (Panax ginseng), causing significant damage to plant growth. The goal of this study was to determine the toxicity and mechanism of action of phenylpropanoids (trans-anethole and estragole) isolated from the methanol extract and hydrodistillate of Illicium verum fruit against third-instar larvae and eggs of B. procera. RESULTS: The filter-paper mortality bioassay revealed that estragole (LC50, 4.68 g/cm(2) ) has a significant fumigant effect, followed by trans-anethole (LC50, 43.92 g/cm(2) ). However, estragole had the lowest toxic effect when compared to commercially available insecticides. After 7 days, estragole and trans-anethole at 75 g/cm(2) inhibited egg hatchability by up to 97 and 93%, respectively. At 0.09 g/cm(2) , insecticides had an inhibitory effect on egg-hatching ability ranging from 88 to 94%. Furthermore, in both closed and open containers, these active constituents were able to consistently induce vapor-phased toxicity. Both estragole and trans-anethole have the ability to inhibit acetylcholinesterase, which is involved in neurotransmitter function. However, the active constituent estragole from I. verum fruit acted as a potent acetylcholinesterase (AChE) inhibitor and had a slightly lower effect on cyclic AMP than octopamine alone. CONCLUSION: This finding suggests that estragole may influence B. procera neurotransmitter function via both the AChE and octopaminergic receptors. More research is needed to demonstrate the potential applications of I. verum fruit-derived products as potential larvicides and ovicides for B. procera population control.
ESTHER : Hong_2022_Pest.Manag.Sci__
PubMedSearch : Hong_2022_Pest.Manag.Sci__
PubMedID: 36358028

Title : Molecular and kinetic properties of three acetylcholinesterases in the Varroa mite, Varroa destructor - Kim_2022_Pestic.Biochem.Physiol_188_105277
Author(s) : Kim S , Yoon KA , Cho S , Lee J , Lim Y , Lee SH
Ref : Pestic Biochem Physiol , 188 :105277 , 2022
Abstract : The Varroa mite, Varroa destructor, poses one of the most serious threats to honey bees worldwide. Although coumaphos, an anticholinesterase pesticide, is widely used for varroa mite control, little information is available on the properties of Varroa mite acetylcholinesterases (VdAChEs). In this study, three putative VdAChEs were annotated and named VdAChE1, VdAChE2, and VdAChE3. All VdAChEs possessed most of the functionally important signature domains, suggesting that they are catalytically active. Phylogenetic analysis revealed that VdAChE1 was clustered into a clade containing most arthropod AChE1s, whereas VdAChE2 and VdAChE3 formed a unique clade with other arachnid AChEs. VdAChE1 was determined to be membrane-anchored, but both VdAChE2 and VdAChE3 are soluble, as judged by electrophoresis in conjunction with western blotting. Tissue-specific transcription profiling revealed that VdAChE1 was most predominantly expressed in the synganglion. In contrast, VdAChE2 was most predominantly expressed in the legs and cuticle. VdAChE3 showed negligible expression levels in all the tissues examined. In a kinetic analysis using recombinant VdAChEs, VdAChE1 exhibited the highest catalytic efficiency, followed by VdAChE2 and VdAChE3. Inhibition experiments revealed that VdAChE1 was most sensitive to all tested inhibitors. Taken together, VdAChE1 appears to be the major synaptic enzyme with a more toxicological relevance, whereas VdAChE2 is involved in other noncatalytic functions, including chemical defense against xenobiotics. Current findings contribute to a more detailed understanding of the evolutionary and functional traits of VdAChEs and to the design of novel anticholinesterase varroacides.
ESTHER : Kim_2022_Pestic.Biochem.Physiol_188_105277
PubMedSearch : Kim_2022_Pestic.Biochem.Physiol_188_105277
PubMedID: 36464382
Gene_locus related to this paper: varde-VdAChE1 , varde-VdAChE2 , varde-VdAChE3

Title : Structural and functional characterization of an auxiliary domain-containing PET hydrolase from Burkholderiales bacterium - Sagong_2022_J.Hazard.Mater_429_128267
Author(s) : Sagong HY , Kim S , Lee D , Hong H , Lee SH , Seo H , Kim KJ
Ref : J Hazard Mater , 429 :128267 , 2022
Abstract : Biodegradation of polyethylene terephthalate (PET) is one of fundamental ways to solve plastic pollution. As various microbial hydrolases have an extra domain unlike PETase from Ideonella sakaiensis (IsPETase), research on the role of these extra domain in PET hydrolysis is crucial for the identification and selection of a novel PET hydrolase. Here, we report that a PET hydrolase from Burkholderiales bacterium RIFCSPLOWO2_02_FULL_57_36 (BbPETase) with an additional N-terminal domain (BbPETase(AND)) shows a similar hydrolysis activity toward microcrystalline PET and a higher thermal stability than IsPETase. Based on detailed structural comparisons between BbPETase and IsPETase, we generated the BbPETase(S335N/T338I/M363I/N365G) variant with an enhanced PET-degrading activity and thermal stability. We further revealed that BbPETase(AND) contributes to the thermal stability of the enzyme through close contact with the core domain, but the domain might hinder the adhesion of enzyme to PET substrate. We suggest that BbPETase is an enzyme in the evolution of efficient PET degradation and molecular insight into a novel PET hydrolase provides a novel strategy for the development of biodegradation of PET.
ESTHER : Sagong_2022_J.Hazard.Mater_429_128267
PubMedSearch : Sagong_2022_J.Hazard.Mater_429_128267
PubMedID: 35091192
Gene_locus related to this paper: 9burk-a0a1f4jxw8

Title : Insecticide resistance in pepper greenhouse populations of Aphis gossypii (Hemiptera: Aphididae) in Korea - Nam_2022_Pestic.Biochem.Physiol_182_105033
Author(s) : Nam HY , Kim S , Lee SH , Lee JH , Kim J
Ref : Pestic Biochem Physiol , 182 :105033 , 2022
Abstract : The cotton aphid or melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a polyphagous insect pest with a wide host range. Two distinct genetic clusters were found in A. gossypii populations in Korea. To determine whether the division of the genetic clusters was driven by insecticide selection pressure, the frequencies of insecticide resistance-associated mutations on three representative insecticide target genes [i.e., nicotinic acetylcholine receptor gene (nAChR), voltage-gated sodium channel gene (vgsc), and acetylcholinesterase 1 gene (ace-1)] were predicted in A. gossypii populations with known genetic structures. Most populations revealed heterozygosity-resistant alleles for the nAChR R81T and vgsc M918L mutations, but homozygous-resistant alleles for the ace-1 S431F mutation. However, assessment of the three mutation frequencies revealed no apparent correlation between the genetic structures and the resistance profiles. The regression analysis revealed no correlation between the genetic cluster ratios and resistance allele frequencies (R81T, S431F, and M918L). We used three insecticides that are commonly used in greenhouses: imidacloprid (neonicotinoid), acephate (organophosphate), and esfenvalerate (pyrethroid), to test resistance and susceptibility in A. gossypii populations. The bioassay results revealed that the BS_19 (Busan) and JE_19 (Jeongeup) populations were resistant to imidacloprid and acephate, the HS_19 (Honseong) population was resistant to acephate and esfenvalerate, and susceptible lab strains only exhibited resistance to acephate. The bioassay results were correlated with mutation frequency, but no correlation was detected among genetic clusters. These results suggest that the distinct genetic structure observed in the Korean populations of A. gossypii is not likely influenced by insecticide resistance traits, but rather by other factors.
ESTHER : Nam_2022_Pestic.Biochem.Physiol_182_105033
PubMedSearch : Nam_2022_Pestic.Biochem.Physiol_182_105033
PubMedID: 35249654

Title : Carboxyl Esterase-TRAIL Expressing Human Adipose Stem Cells Inhibit Tumor Growth in Castration-Resistant Prostate Cancer-Bearing Mice with Less Toxicity - Kim_2022_Technol.Cancer.Res.Treat_21_15330338221093146
Author(s) : Kim JH , Oh E , Yun CW , Lee SH , Song YS
Ref : Technol Cancer Research Treat , 21 :15330338221093146 , 2022
Abstract : It has been proposed that CRPC treatment with reduced systemic toxicity can be achieved by employing genes that express enzymes that activate pharmacological agents. In this paper, we report our study that used human adipose-derived stem cells (ADSC), rabbit CE, and human TRAIL with reduced toxicity to explore how tumor development can be suppressed in CRPC-bearing mouse models. In vitro and in vivo directional migration of ADSC.CE.sTRAIL cells toward PC3 cells was significantly stimulated.ADSC.CE.sTRAIL showed higher suicide effects than did ADSC, ADSC.CE, or ADSC.sTRAIL under CPT-11 treatment. PC3 cells co-cultured with ADSC.CE.TRAIL showed higher cytotoxicity than did CPT-11 monotherapy, ADSC.CE, or ADSC.sTRAIL under CPT-11 treatment. ADSC.CE.sTRAIL showed higher apoptosis than did CPT-11 monotherapy, ADSC.CE, or ADSC.sTRAIL under CPT-11 treatment. In the in vivo study, ADSC.CE.sTRAIL inhibited tumor growth more than did CPT-11 monotherapy, ADSC.CE, or ADSC.sTRAIL under CPT-11 treatment. The evidence suggests that patients' own ADSC could be used in clinical trials for CRPC treatment based on therapeutic stem cells that express CE and TRAIL complex genes.
ESTHER : Kim_2022_Technol.Cancer.Res.Treat_21_15330338221093146
PubMedSearch : Kim_2022_Technol.Cancer.Res.Treat_21_15330338221093146
PubMedID: 35491733

Title : Molecular and kinetic characterization of two acetylcholinesterases with particular focus on the roles of two amino acid substitutions (Y390N and F392W) in Bemisia tabaci - Kim_2022_Pestic.Biochem.Physiol_182_105039
Author(s) : Kim S , Yoon KA , Cho S , Lee SH
Ref : Pestic Biochem Physiol , 182 :105039 , 2022
Abstract : Two acetylcholinesterases (AChEs) are present in Bemisia tabaci (BtAChE1 and BtAChE2). A conserved AChE mutation conferring organophosphate (OP) resistance (F392W in BtAChE1) is saturated in field populations despite its potential fitness cost, and a highly conserved amino acid residue forming the backdoor of AChE is substituted with a unique amino acid (Y390N in BtAChE1) in B. tabaci. Thus, the roles and relationships of the two amino acid substitutions in the evolutionary adaptation of B. tabaci remain to be elucidated, and little information is available on the catalytic and molecular properties of BtAChE1 and BtAChE2. To determine which AChE is a more relevant target of OPs and carbamates, the molecular and kinetic properties of BtAChE1 and BtAChE2 were investigated. Both BtAChE1 and BtAChE2 were exclusively expressed in head and thorax but not in abdomen, bound to the membrane via GPI anchoring, and present as dimeric forms. Soluble monomeric form was detected only in BtAChE2. The catalytic activity of baculovirus-expressed BtAChE1 was 19.5-fold higher than that of BtAChE2. The inhibition assay revealed that the F392W mutation in BtAChE1 enhanced resistance to OPs. The artificial substitution of N390 (wild form) to Y (putative ancient form) led to reduced catalytic efficiency and increased inhibition by glycoalkaloids, suggesting that the Y390N substitution in BtAChE1 may have been required for Solanaceae host adaptation. BtAChE1 was proven to function as a main catalytic enzyme for ACh hydrolysis, thus being the main target of OPs and carbamates.
ESTHER : Kim_2022_Pestic.Biochem.Physiol_182_105039
PubMedSearch : Kim_2022_Pestic.Biochem.Physiol_182_105039
PubMedID: 35249657
Gene_locus related to this paper: bemta-ACHE1 , bemta-ACHE2

Title : Current biotechnologies on depolymerization of polyethylene terephthalate (PET) and repolymerization of reclaimed monomers from PET for bio-upcycling: A critical review - Kim_2022_Bioresour.Technol_363_127931
Author(s) : Kim NK , Lee SH , Park HD
Ref : Bioresour Technol , 363 :127931 , 2022
Abstract : The production of polyethylene terephthalate (PET) has drastically increased in the past half-century, reaching 30 million tons every year. The accumulation of this recalcitrant waste now threatens diverse ecosystems. Despite efforts to recycle PET wastes, its rate of recycling remains limited, as the current PET downcycling is mostly unremunerative. To address this problem, PET bio-upcycling, which integrates microbial depolymerization of PET followed by repolymerization of PET-derived monomers into value-added products, has been suggested. This article critically reviews current understanding of microbial PET hydrolysis, the metabolic mechanisms involved in PET degradation, PET hydrolases, and their genetic improvement. Furthermore, this review includes the use of meta-omics approaches to search PET-degrading microbiomes, microbes, and putative hydrolases. The current development of biosynthetic technologies to convert PET-derived materials into value-added products is also comprehensively discussed. The integration of various depolymerization and repolymerization biotechnologies enhances the prospects of a circular economy using waste PET.
ESTHER : Kim_2022_Bioresour.Technol_363_127931
PubMedSearch : Kim_2022_Bioresour.Technol_363_127931
PubMedID: 36100185

Title : Short communication: Screening of proof-of-concept mutations of honey bee acetylcholinesterase 2 conferring resistance to organophosphorus and carbamate insecticides - Kim_2022_Comp.Biochem.Physiol.C.Toxicol.Pharmacol__109524
Author(s) : Kim S , Yoon KA , Lee SH
Ref : Comparative Biochemistry & Physiology C Toxicol Pharmacol , :109524 , 2022
Abstract : The introduction of pesticide resistance-inducing mutations into target genes would in theory protect honey bees from the hazardous effects of pesticides. In this paper, to screen amino acid substitutions conferring resistance to organophosphorus and carbamate insecticides, honey bee acetylcholinesterase 2 (AmAChE2) variants with several mutations (V260L, A316S, G342A, G342V, F407Y, and G342V/F407Y) were generated and expressed in vitro using a baculovirus system. The inhibition constants of recombinant native and mutated AmAChE2s against six pesticides were measured. As a result, the A316S mutation was shown to induce high resistance without a catalytic efficiency change.
ESTHER : Kim_2022_Comp.Biochem.Physiol.C.Toxicol.Pharmacol__109524
PubMedSearch : Kim_2022_Comp.Biochem.Physiol.C.Toxicol.Pharmacol__109524
PubMedID: 36410640

Title : TSPO Expression Modulatory Effect of Acetylcholinesterase Inhibitor in the Ischemic Stroke Rat Model - Song_2021_Cells_10_
Author(s) : Song YS , Lee SH , Jung JH , Song IH , Park HS , Moon BS , Kim SE , Lee BC
Ref : Cells , 10 : , 2021
Abstract : We performed in vivo PET imaging with 3-[(18)F]F-CP118,954 (1) for acetylcholinesterase (AChE) and [(18)F]fluoromethyl-PBR28-d(2) (2) for translocator protein 18-kDa (TSPO) to investigate the inflammatory brain response after stroke. Imaging studies were performed in the middle cerebral artery occlusion (MCAO) Sprague-Dawley rat model for a period of three weeks. The percentage injected dose per tissue weight (%ID/g) of striatum of 1, and cortex of 2 were obtained, respectively. To trace the sequential inflammatory responses, AChE imaging of 1 was done on post-MCAO day 2, after giving cold PK-11195 for 1 day, and TSPO imaging of 2 was carried out on post-MCAO day 11, after giving donepezil for 10 days. AChE activity in the MCAO-lesioned side were significantly higher than that of the contralateral side on day one, and TSPO activity was highest on day 11. TSPO inhibitor, PK-11195 did not affect AChE activity on day two, while AChE inhibitor, donepezil significantly lowered TSPO binding on day 12. Our study demonstrates that AChE level is elevated in the early course of brain ischemia as a trigger for the inflammatory response, and TSPO level is elevated persistently throughout the post-ischemic injury in the brain. Also, the AChE inhibitor may be able to inhibit or delay neurotoxic inflammatory responses and serve as a beneficial treatment option.
ESTHER : Song_2021_Cells_10_
PubMedSearch : Song_2021_Cells_10_
PubMedID: 34072449

Title : Neuroprotective effects of ethanolic extract from dry Rhodiola rosea L. rhizomes - Kim_2021_Food.Sci.Biotechnol_30_287
Author(s) : Kim KJ , Jung YS , You DM , Lee SH , Lee G , Kwon KB , Kim DO
Ref : Food Sci Biotechnol , 30 :287 , 2021
Abstract : Rhodiola rosea L. rhizome has been used as a traditional medicine to treat fatigue, depression, and cognitive dysfunction. We aimed to authenticate R. rosea L. rhizome using the DNA barcoding technique and to quantify its main compounds, total phenolics, total flavonoids, and antioxidant capacity, and then to investigate their neuroprotective effects. The sequences of internal transcribed spacer and trnH-psbA of R. rosea L. rhizomes showed a 99% identity with those of NCBI GenBank database according to BLAST searches. Analysis using reversed-phase HPLC revealed five main compounds in R. rosea L. rhizome. Rhodiola rosea L. rhizome and two bioactive compounds, salidroside and tyrosol, showed free radical scavenging activity. Rhodiola rosea L. rhizome and its identified compounds protected neuronal PC-12 cells against oxidative stress and showed moderate acetylcholinesterase inhibition. Taken together, these results suggest that R. rosea L. rhizomes with bioactives can be used as a functional ingredient with potential for neuroprotection. SUPPLEMENTARY INFORMATION: The online version of this article (doi:10.1007/s10068-020-00868-7) contains supplementary material, which is available to authorized users.
ESTHER : Kim_2021_Food.Sci.Biotechnol_30_287
PubMedSearch : Kim_2021_Food.Sci.Biotechnol_30_287
PubMedID: 33732519

Title : Allium hookeri Extracts Improve Scopolamine-Induced Cognitive Impairment via Activation of the Cholinergic System and Anti-Neuroinflammation in Mice - Choi_2021_Nutrients_13_
Author(s) : Choi JH , Lee EB , Jang HH , Cha YS , Park YS , Lee SH
Ref : Nutrients , 13 : , 2021
Abstract : Allium hookeri (AH) is a medicinal food that has been used in Southeast Asia for various physiological activities. The objective of this study was to investigate the activation of the cholinergic system and the anti-neuroinflammation effects of AH on scopolamine-induced memory impairment in mice. Scopolamine (1 mg/kg body weight, i.p.) impaired the performance of the mice on the Y-maze test, passive avoidance test, and water maze test. However, the number of error actions was reduced in the AH groups supplemented with leaf and root extracts from AH. AH treatment improved working memory and avoidance times against electronic shock, increased step-through latency, and reduced the time to reach the escape zone in the water maze test. AH significantly improved the cholinergic system by decreasing acetylcholinesterase activity, and increasing acetylcholine concentration. The serum inflammatory cytokines (IL-1beta, IL-6, and IFN-gamma) increased by scopolamine treatment were regulated by the administration of AH extracts. Overexpression of NF-kappaB signaling and cytokines in liver tissue due to scopolamine were controlled by administration of AH extracts. AH also significantly decreased Abeta and caspase-3 expression but increased NeuN and ChAT. The results suggest that AH extracts improve cognitive effects, and the root extracts are more effective in relieving the scopolamine-induced memory impairment. They have neuroprotective effects and reduce the development of neuroinflammation.
ESTHER : Choi_2021_Nutrients_13_
PubMedSearch : Choi_2021_Nutrients_13_
PubMedID: 34445062

Title : Insecticide resistance trait may contribute to genetic cluster change in Bemisia tabaci MED (Hemiptera: Aleyrodidae) as a potential driving force - Park_2021_Pest.Manag.Sci__
Author(s) : Park Y , Kim S , Lee SH , Lee JH
Ref : Pest Manag Sci , : , 2021
Abstract : BACKGROUND: Previously, we had reported that the majority of the Bemisia tabaci Mediterranean (MED) populations converged from two dominant genetic clusters (cluster 1 and 2) to one (cluster 2) during one year in greenhouse tomatoes in Korea. To find possible mechanisms for this phenomenon, we investigated the concurrent changes in resistance traits of the two clusters for three insecticide classes (organophosphate, pyrethroid, and neonicotinoid). RESULTS: Since the resistance mutation frequencies in regional samples were either high (i.e., the voltage-sensitive sodium channel L925I/T929V mutations and the F392 acetylcholinesterase 1 mutation) or zero (the nicotinic acetylcholine receptor R81T mutation), no meaningful correlation between the resistance allele frequency and genetic cluster was deduced. However, the actual resistance levels to all three insecticide classes were significantly higher in cluster 2 than those in cluster 1, suggesting that cluster 2 has a higher resistance potential. Furthermore, thiamethoxam treatment to the mixed population of clusters 1 and 2 over three generations exhibited a strong tendency of population change from cluster 1 to cluster 2. CONCLUSION: Our results demonstrated that the insecticide resistance trait is one of the driving forces for rapid genetic cluster change in the B. tabaci MED populations.
ESTHER : Park_2021_Pest.Manag.Sci__
PubMedSearch : Park_2021_Pest.Manag.Sci__
PubMedID: 33843146
Gene_locus related to this paper: bemta-ACHE1

Title : Enhanced inhibition of tumor growth using TRAIL-overexpressing adipose-derived stem cells in combination with the chemotherapeutic agent CPT-11 in castration-resistant prostate cancer - Kim_2021_Prostate.Int_9_31
Author(s) : Kim JH , Oh E , Han YS , Lee SH , Song YS
Ref : Prostate Int , 9 :31 , 2021
Abstract : BACKGROUND: This study investigated the inhibition of tumor growth in castrate-resistant prostate cancer (CRPC)-bearing mice by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-overexpressing adipose-derived stem cells (ADSCs) (hTERT-ADSC.sTRAIL), which was enhanced by combined treatment with CPT-11. MATERIALS AND METHODS: An hTERT-ADSC.sTRAIL cell line was established by transfection with a lentiviral vector (CLV-Ubic) encoding the human sTRAIL gene. Quantitative polymerase chain reaction and Western blots were performed to confirm gene overexpression. An invasion study for the selective migration ability toward PC3 cells was performed. In the in vivo study, the tumor volume in mice treated with ADSC. sTRAIL and CPT-11 was measured. RESULTS: Carboxylesterase was generated from hTERT-ADSCs. The gene expression of sTRAIL from hTERT-ADSC.sTRAIL was shown. The directional migration of ADSC.sTRAIL cells toward PC3 cells was significantly stimulated by PC3 cells in vitro (P < 0.05). In the in vitro study, the viability of PC3 cells significantly decreased in the presence of ADSC.sTRAIL (62.7 +/- 2.0%) and CPT-11 compared with that of CPT-11 alone (83.0 +/- 1.0%) at a cell ratio as low as 0.05 (PC3: ADSC.sTRAIL) (P < 0.05). The proportion of apoptotic PC3 cells significantly increased in the presence of ADSC.sTRAIL (37.2 +/- 2.1%) and CPT-11 compared with that of CPT-11 alone (16.5 +/- 1.0%) (P < 0.05). In the in vivo study, the inhibition of tumor growth in CRPC-bearing mice by TRAIL-overexpressing adipose stem cells was enhanced by combined treatment with the chemotherapeutic agent CPT-11 compared with that in the treatment with cpt-11 alone. Immunohistochemical staining of the removed tumors showed anti-TRAIL-positive cells and apoptotic bodies after hTERT-ADSC.sTRAIL treatment or combined treatment with hTERT-ADSC.sTRAIL and CPT-11. CONCLUSIONS: Therapeutic stem cells expressing sTRAIL genes combined with CPT-11 can provide a new strategy for treating CRPC in clinical trials using the patients' own ADSCs.
ESTHER : Kim_2021_Prostate.Int_9_31
PubMedSearch : Kim_2021_Prostate.Int_9_31
PubMedID: 33912512

Title : Regional and seasonal detection of resistance mutation frequencies in field populations of Anopheles Hyrcanus Group and Culex pipiens complex in Korea - Lee_2020_Pestic.Biochem.Physiol_164_33
Author(s) : Lee DE , Kim HC , Chong ST , Klein TA , Choi KS , Kim YH , Kim JH , Lee SH
Ref : Pestic Biochem Physiol , 164 :33 , 2020
Abstract : Pyrethroid (PYR) and organophosphate (OP) insecticides have been extensively used for mosquito control for several decades in South Korea, and has resulted in the rapid development of resistance in the field. In this study, quantitative sequencing (QS) protocols were developed for the frequency prediction of insecticide resistance alleles [e.g., the L1014F/C mutation on the voltage sensitive sodium channel as a PYR resistance allele and the G119S mutation on the acetylcholinesterase 1 as OP resistance alleles] in four regional populations of Anopheles Hyrcanus Group and Culex pipiens complex. Both of the L1014F/C and G119S mutations were observed in all examined regional populations of An. Hyrcanus Group, suggesting a wide distribution of both PYR and OP resistance. In contrast, populations of the Cx. pipiens complex were determined to possess almost no G119S mutation, but relatively higher frequencies of the L1014F mutation, showing differential resistance patterns between different mosquito groups. The mutation frequencies were also monitored throughout a mosquito season (May-October) at one collection site to determine the seasonal changes of resistance mutation frequency in mosquito populations. Dramatic decreases of both L1014F/C and G119S mutation frequencies were observed in the An. Hyrcanus Group toward the fall, with no mutations observed in the early spring, suggesting a connection between the fitness costs of overwintering and insecticide resistance. However, no apparent trends were detectable in the Cx. pipiens complex populations due to low or zero mutation frequencies.
ESTHER : Lee_2020_Pestic.Biochem.Physiol_164_33
PubMedSearch : Lee_2020_Pestic.Biochem.Physiol_164_33
PubMedID: 32284134

Title : Aberrant expression of S-SCAM causes the loss of GABAergic synapses in hippocampal neurons - Shin_2020_Sci.Rep_10_83
Author(s) : Shin SM , Skaar S , Danielson E , Lee SH
Ref : Sci Rep , 10 :83 , 2020
Abstract : The duplication and deletion mutations of the S-SCAM/MAGI-2 gene are associated with schizophrenia and infantile spasms, respectively. S-SCAM is a unique synaptic scaffolding protein that localizes to both excitatory and GABAergic synapses. However, consequences of aberrant S-SCAM expression on GABAergic synapses is little studied. Here we report the effect of S-SCAM knockdown and overexpression on GABAergic synapses. S-SCAM knockdown in cultured hippocampal neurons caused a drastic loss of both pre- and post-synaptic components of GABAergic synapses, indicating its essential role in GABAergic synapse formation and maintenance. Surprisingly, S-SCAM overexpression also attenuated GABAergic synapses, but the effect is mediated by the loss of postsynaptic GABAA receptors, gephyrin, and neuroligin 2 and does not involve presynaptic component vesicular GABA transporters. Overexpression studies using S-SCAM mutants with various domain deletions indicated that GABAergic synapse loss correlates with their ability to increase excitatory synaptic function. Consistently, AMPA receptor antagonist CNQX or calcineurin inhibitor FK506 abolished the S-SCAM overexpression-induced loss of GABAA receptors, supporting that GABAergic synapse loss by S-SCAM overexpression is due to the activity-induced dispersal of synaptic GABAA receptors. These results suggest that abnormal S-SCAM protein levels disrupt excitation/inhibition balance in neurons, which may explain the pathogenic nature of S-SCAM copy number variations.
ESTHER : Shin_2020_Sci.Rep_10_83
PubMedSearch : Shin_2020_Sci.Rep_10_83
PubMedID: 31919468

Title : Structural bioinformatics-based protein engineering of thermo-stable PETase from Ideonella sakaiensis - Son_2020_Enzyme.Microb.Technol_141_109656
Author(s) : Son HF , Joo S , Seo H , Sagong HY , Lee SH , Hong H , Kim KJ
Ref : Enzyme Microb Technol , 141 :109656 , 2020
Abstract : Poly(ethylene terephthalate) (PET), a widely used plastic around the world, causes various environmental and health problems. Several groups have been extensively conducting research to solve these problems through enzymatic degradation of PET at high temperatures around 70 degC. Recently, Ideonella sakaiensis, a bacterium that degrades PET at mild temperatures, has been newly identified, and further protein engineering studies on the PET degrading enzyme from the organism (IsPETase) have also been conducted to overcome the low thermal stability of the enzyme. In this study, we performed structural bioinformatics-based protein engineering of IsPETase to optimize the substrate binding site of the enzyme and developed two variants, IsPETase(S242T) and IsPETase(N246D), with higher enzymatic activity at both 25 and 37 degC compared with IsPETase(WT). We also developed the IsPETase(S121E/D186H/S242T/N246D) variant by integrating the S242T and N246D mutations into the previously reported IsPETase(S121E/D186H/R208A) variant. At the 37 degC incubation, the quadruple variant maintained the PET degradation activity for 20 days, unlike IsPETase(WT) that lost its activity within a day. Consequently, this study exhibited 58-fold increase in the activity compared with IsPETase(WT).
ESTHER : Son_2020_Enzyme.Microb.Technol_141_109656
PubMedSearch : Son_2020_Enzyme.Microb.Technol_141_109656
PubMedID: 33051015
Gene_locus related to this paper: idesa-mheth

Title : An adenoviral vector encoded with the GPx-1 gene attenuates memory impairments induced by beta-amyloid (1-42) in GPx-1 KO mice via activation of M1 mAChR-mediated signaling - Shin_2020_Free.Radic.Res__1
Author(s) : Shin EJ , Lee SH , Sharma N , Nguyen BT , Chung YH , Kang SW , Nah SY , Lee YJ , Nabeshima T , Jeong JH , Kim HC
Ref : Free Radical Research , :1 , 2020
Abstract : In the present study, we examined whether glutathione peroxidase-1 (GPx-1), a major H(2)O(2) scavenger in the brain, affects memory deficits induced by Abeta (1-42) in mice. Treatment with 400 pmol/5 l Abeta (1-42) (i.c.v.) resulted in a reduction of GPx-1 expression in wild type (WT) mice. An Abeta (1-42)-induced reduction in acetylcholine (ACh) level was observed in the hippocampus. Treatment with Abeta (1-42) consistently resulted in reduced expression and activity of choline acetyltransferase (ChAT) and in an increase in expression and activity of acetylcholinesterase (AChE). Upon examining each of the muscarinic acetylcholine receptors (mAChRs) and nicotinic AChRs, we noted that Abeta (1-42) treatment selectively reduced the levels of M1 mAChR. In addition, Abeta (1-42) induced a significant reduction in phospho-cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) expression. The cholinergic impairments induced by Abeta (1-42) were more pronounced in GPx-1 knockout mice than in WT mice. Importantly, an adenoviral vector encoded with the GPx-1 gene (Ad-GPx-1) significantly rescued Abeta (1-42)-induced cholinergic impairments in GPx-1 knockout mice. In addition, M1 mAChR antagonist dicyclomine significantly counteracted Ad-GPx-1-mediated increases in p-CREB and BDNF expression, as well as memory-enhancing effects in GPx-1 knockout mice, thus indicating that M1 mAChR might be a critical mediator for the rescue effects of Ad-GPx-1. Combined, our results suggest that GPx-1 gene protected against Abeta (1-42)-induced memory impairments via activation of M1 mAChR-dependent CREB/BDNF signaling.
ESTHER : Shin_2020_Free.Radic.Res__1
PubMedSearch : Shin_2020_Free.Radic.Res__1
PubMedID: 33222572

Title : Differential expression of acetylcholinesterase 1 in response to various stress factors in honey bee workers - Kim_2019_Sci.Rep_9_10342
Author(s) : Kim S , Kim K , Lee JH , Han SH , Lee SH
Ref : Sci Rep , 9 :10342 , 2019
Abstract : The honey bee acetylcholinesterase 1 (AmAChE1) has been suggested to be related to stress response as judged from its elevated expression level under brood rearing-suppressed conditions. To further investigate the involvement of AmAChE1 expression in the stress response and its physiological functions, we analyzed altered expression profiles of AmAChE1 induced by diverse stress factors. In addition, transcription profiles of several heat shock protein (Hsp) genes (hsps) and the vitellogenin (Vg) gene (vg) known as general stress markers were investigated as positive references. Among the tested stress conditions, AmAChE1 expression was induced under the brood rearing-suppressed, crowding and heat shock conditions. The hsps, particularly hsp70 and hsp90, responded to seven of nine stress conditions tested, confirming that hsp expression profiles can serve as a general stress marker. Taken together, AmAChE1 expression is not suitable for using as a stress marker due to its limited response. Nevertheless, AmAChE1 expression appears to be connected, at least in part, to heat shock response and other pathways. Considering that AmAChE1 likely regulates the ACh titer particularly in non-neuronal tissues, thereby modulating the signal cascades mediated by mAChR, the AmAChE1 expression profile under different conditions likely provides important information on its physiological roles in honey bees.
ESTHER : Kim_2019_Sci.Rep_9_10342
PubMedSearch : Kim_2019_Sci.Rep_9_10342
PubMedID: 31316163

Title : Aster glehni Extract Ameliorates Scopolamine-Induced Cognitive Impairment in Mice - Liao_2019_J.Med.Food_22_685
Author(s) : Liao Y , Bae HJ , Park JH , Zhang J , Koo B , Lim MK , Han EH , Lee SH , Jung SY , Lew JH , Ryu JH
Ref : J Med Food , 22 :685 , 2019
Abstract : The leaves of Aster glehni Fr. Schm. (Asteraceae) have been used to treat insomnia in Korea. Insomnia is a common adverse effect of therapeutic agents for Alzheimer's disease (AD), and the control of sleep disturbance may prevent dementia. We hypothesized that the leaves of A. glehni can attenuate cognitive dysfunctions observed in AD. We observed the ameliorating effects of the ethanolic extract of leaves of A. glehni (AG-D) on memory dysfunction through the Morris water maze test, the passive avoidance test, and the Y-maze test. We performed acetylcholinesterase (AChE) activity assay and Western blotting to determine the mechanism of action of AG-D. AG-D significantly attenuated memory dysfunction observed in the above behavior studies and inhibited the activity of AChE. AG-D also increased the levels of phosphorylation extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB), phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and glycogen synthase kinase 3beta (GSK-3beta) and the expression levels of brain-derived neurotrophic factor (BDNF) in the hippocampi. These results suggest that AG-D ameliorates memory impairments by AChE inhibition and activation of ERK-CREB-BDNF and PI3K-Akt-GSK-3beta signaling pathways. Taken together, this study suggests that AG-D could be used as a potential treatment for cognitive dysfunction.
ESTHER : Liao_2019_J.Med.Food_22_685
PubMedSearch : Liao_2019_J.Med.Food_22_685
PubMedID: 31225769

Title : Molecular and biochemical characterization of the bed bug salivary gland cholinesterase as an acetylcholine-sequestering enzyme - Kim_2018_Insect.Biochem.Mol.Biol_102_52
Author(s) : Kim JH , Hwang CE , Yoon KA , Seong KM , Lee J , Lee SH
Ref : Insect Biochemistry & Molecular Biology , 102 :52 , 2018
Abstract : The common bed bug, Cimex lectularius, possesses a cholinesterase expressed exclusively in the salivary gland (ClSChE). In this study, we investigated the molecular forms, tissue distribution patterns and biochemical properties of ClSChE and showed that ClSChE exists as a soluble monomeric form or a soluble dimeric form connected by a disulfide bridge. Immunohistochemical analysis confirmed that ClSChE was expressed in the epithelial cells of both the salivary gland and the duct. In addition, the secretion of monomeric ClSChE through the proboscis during feeding was confirmed by western blotting using a ClSChE-specific antibody. To predict the role of ClSChE injected into the tissue of an animal host, we analyzed the extent of hydrolysis of acetylcholine (ACh) by ClSChE by ultra-performance liquid chromatography-tandem mass spectrometry. ClSChE binding to ACh was not clearly resolved in the binding assay format used in this study, probably due to the weak but detectable ACh-hydrolytic activity of ClSChE. Nevertheless, kinetic analysis revealed that ClSChE possesses extremely low Km (high affinity to ACh) and Vmax values. These findings suggest that ClSChE functions virtually as an ACh-sequestering protein by having a very strong affinity to ACh but an extremely long turnover time. Given that ACh regulates a wide variety of host physiologies, we discuss the tentative roles of ClSChE in blood vessel constriction and itch/pain regulation in the host.
ESTHER : Kim_2018_Insect.Biochem.Mol.Biol_102_52
PubMedSearch : Kim_2018_Insect.Biochem.Mol.Biol_102_52
PubMedID: 30266661
Gene_locus related to this paper: cimle-d1fqg8

Title : Ethanolic Extract of Opuntia ficus-indica var. saboten Ameliorates Cognitive Dysfunction Induced by Cholinergic Blockade in Mice - Kwon_2018_J.Med.Food_21_971
Author(s) : Kwon Y , Liao Y , Koo B , Bae H , Zhang J , Han EH , Yun SM , Lim MK , Lee SH , Jung SY , Ryu JH
Ref : J Med Food , 21 :971 , 2018
Abstract : The stem of Opuntia ficus-indica var. saboten is edible and has been used as a medicinal herb on Jeju Island in Korea. We previously reported that the butanolic extract of O. ficus-indica var. saboten exerts the enhancement of long-term memory in mice. However, the antiamnesic effects of O. ficus-indica var. saboten and its mode of action has not been clearly elucidated. In the present study, we explored the effects of the ethanolic extract of stems of O. ficus-indica var. saboten (EOFS) on cognitive performance in mouse and attempted to delineate its mechanism of action. We used the passive avoidance, Y-maze, and novel object recognition tests to assess its effects on cognitive functions in scopolamine-induced memory-impaired mice. We observed that EOFS (100, 200, and 400 mg/kg) ameliorated scopolamine-induced cognitive dysfunction. We also explored its mechanism of action by conducting an acetylcholinesterase (AChE) activity assay using the mouse whole brain and Western blot using the mouse hippocampal tissue. Western blot analysis and the ex vivo study revealed that EOFS increased the levels of phosphorylated extracellular signal-regulated kinase and cAMP response element-binding protein (CREB) and the levels of brain-derived neurotrophic factor (BDNF) expression in the hippocampus. It also inhibited AChE activity in the brain. Our findings suggest that EOFS would be useful for the treatment of cholinergic blockade-induced cognitive dysfunction.
ESTHER : Kwon_2018_J.Med.Food_21_971
PubMedSearch : Kwon_2018_J.Med.Food_21_971
PubMedID: 30044674

Title : Deastringent Peel Extracts of Persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) Protect Neuronal PC-12 and SH-SY5Y Cells against Oxidative Stress - Jeong_2018_J.Microbiol.Biotechnol_28_1094
Author(s) : Jeong DW , Cho CH , Lee JS , Lee SH , Kim T , Kim DO
Ref : J Microbiol Biotechnol , 28 :1094 , 2018
Abstract : The peel of astringent persimmon (Diospyros kaki Thunb. cv. Cheongdo-Bansi) is a by-product of dried persimmon (gotgam). We investigated if deastringent peel extracts of persimmon cv. Cheongdo-Bansi had antioxidative and neuroprotective properties. Two different extracts were prepared: thermally and nonthermally treated persimmon peel extracts (TPE and NTPE, respectively). Both TPE and NTPE were fractionated sequentially in n-hexane, chloroform, ethyl acetate, n-butanol, and water. The TPE and NTPE ethyl acetate fractions had the highest total phenolic and flavonoid contents as well as antioxidant capacities among all the fractions. Pretreatment of neuronal PC-12 and SH-SY5Y cells with the TPE and NTPE ethyl acetate fractions increased cell viability after exposure to oxidative stress. The ethyl acetate fraction of TPE attenuated oxidative stress inside both PC-12 and SH-SY5Y cells more effectively than that of NTPE. Furthermore, the TPE and NTPE ethyl acetate fractions inhibited acetylcholinesterase and butyrylcholinesterase. Analysis of ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry results revealed gallic acid, kaempferol, kaempferol-3-O-galactoside, kaempferol-3-O-glucoside, quercetin, quercetin-3-O-galactoside, quercetin-3-O-galactoside-2'-O-gallate, and quercetin-3-O-glucoside as the major phenolics of the TPE and NTPE ethyl acetate fractions. Taken together, these results suggest that the ethyl acetate fraction of deastringent persimmon peel is rich in antioxidants and has potential as a functional food to reduce oxidative stress.
ESTHER : Jeong_2018_J.Microbiol.Biotechnol_28_1094
PubMedSearch : Jeong_2018_J.Microbiol.Biotechnol_28_1094
PubMedID: 29975999

Title : Ionic liquids as cosolvents for the lipase-catalyzed kinetic resolution of ketoprofen - Park_2018_Mol.Catal_459_113
Author(s) : Park S , Doan TTN , Koo Y-M , Oh KK , Lee SH
Ref : Molecular Catalysis , 459 :113 , 2018
Abstract : This study examined the use of ionic liquids (ILs) as cosolvents for the Candida rugosa lipase-catalyzed enantioselective hydrolysis of racemic ketoprofen ethyl ester. To determine the effect of the IL anion structures on the lipase activity and enantioselectivity, six ILs containing the 1-butyl-3-methylimidazolium ([Bmim]) cation were used as cosolvents and their solvent properties were correlated with various reaction characteristics. The highest lipase activities were obtained using [Bmim][BF4] and [Bmim][MeSO4] as cosolvents. The enantioselectivity (E) of lipase was enhanced by a factor of 50 with 5% [Bmim][MeSO4]. Although the conversion, enantiomeric excess of product (eep), and E value in 5% [Bmim][MeSO4] were 47.3%, >99%, and -300, respectively, the corresponding lipase stability is inadequate for commercial application. Excluding [Bmim][MeSO4], the lipase enantioselectivity increased with decreasing hydrogen bond basicity (beta) of the IL when the log E values of lipase in 5% ILs were correlated with IL solvent parameters. With [Bmim][PF6] as the cosolvent, which has the lowest beta value among all ILs examined, the E value was enhanced by a factor of 32. The conversion and eep in 20% [Bmim][PF6] were 48.0% and 96.9%, respectively. Additionally, the lipase stability in aqueous [Bmim][PF6] solution was much higher than that in aqueous [Bmim][MeSO4] solution.
ESTHER : Park_2018_Mol.Catal_459_113
PubMedSearch : Park_2018_Mol.Catal_459_113

Title : Protection of Grain Products from Sitophilus oryzae (L.) Contamination by Anti-Insect Pest Repellent Sachet Containing Allyl Mercaptan Microcapsule - Chang_2017_J.Food.Sci_82_2634
Author(s) : Chang Y , Lee SH , Na JH , Chang PS , Han J
Ref : J Food Sci , 82 :2634 , 2017
Abstract : The purpose of this study was to develop an anti-insect pest repellent sachet to prevent Sitophilus oryzae (L.) (Coleoptera: Curculionidae) contamination in grain packaging. The anti-insect pest activities of essential oils (EOs) from garlic (Allium Sativum), ginger (Zingiber Officinalis), black pepper (Piper nigrum), onion (Allium cepa), and fennel (Foeniculum vulgare) as well as major compounds (allyl disulfide, AD; allyl mercaptan, AM) isolated from of garlic and onion (AD and AM) were measured against S. oryzae. The results revealed that garlic EO, onion EO, AD, and AM showed strong fumigant insecticidal activities. Among these, AM showed the highest acetylcholinesterase (AChE) inhibition rate, indicating that the fumigation insecticidal efficacy of AM is related with its AChE inhibition ability. Subsequently, the microcapsules were produced with a high efficiency (80.02%) by using AM as a core material and rice flour as a wall material. Finally, sachet composed of rice flour microcapsule containing 2% AM (RAM) was produced. Repellent assay was performed to measure anti-insect pest ability of the RAM sachet, showed remarkable repelling effect within 48 h both in the presence or absence of attractant. In a release profile of RAM sachet, it was expected to last over 20 mo during the distribution period of brown rice. Moreover, RAM sachet showed no undesirable changes to the sensory properties of the rice both before and after cooking. Taken together, these results suggest that the newly developed RAM sachet could be used as a packaging material to protect grain products from S. oryzae contamination. PRACTICAL APPLICATION: The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), causes damages to stored products and its contamination in grain products has become a major problem in cereal market. To preserve brown rice, an anti-insect pest repellent sachet containing 2% allyl mercaptan was newly developed and it showed remarkable repellent abilities against S. oryzae. It could be used as an active food packaging system to protect grain products from insect pest contamination.
ESTHER : Chang_2017_J.Food.Sci_82_2634
PubMedSearch : Chang_2017_J.Food.Sci_82_2634
PubMedID: 29030875

Title : Effects of overweight and the PLA2G7 V279F polymorphism on the association of age with systolic blood pressure - Kim_2017_PLoS.One_12_e0173611
Author(s) : Kim M , Yoo HJ , Jang HY , Lee SH , Lee JH
Ref : PLoS ONE , 12 :e0173611 , 2017
Abstract : This prospective study aimed to determine the effects of the persistence of overweight for three years and the PLA2G7 V279F polymorphism, as well as the interaction between these factors, on the association of age with blood pressure (BP). Healthy middle-aged subjects with normotensive BP were divided into the normal-weight and overweight groups. The PLA2G7 V279F genotype, BP, lipoprotein-associated phospholipase A2 (Lp-PLA2) activity, and oxidized low-density lipoprotein (ox-LDL) were determined. Lp-PLA2 activity was lower in the F allele subjects (n = 111) than in those with the VV genotype (n = 389). The overweight individuals with the F allele had lower Lp-PLA2 activity and ox-LDL at both baseline and after three years and lower systolic and diastolic BP and LDL cholesterol after three years compared with those with the VV phenotype. After three years, the overweight subjects with the VV phenotype exhibited greater increases in Lp-PLA2 activity, systolic BP, and ox-LDL than those with the F allele and normal-weight subjects with the VV phenotype. A multivariate analysis revealed that the PLA2G7 V279F genotype, baseline BMI, changes in Lp-PLA2 activity and ox-LDL remained independently and positively associated with changes in systolic BP. The simultaneous presence of the PLA2G7 279VV genotype and persistence of overweight synergistically increases the risk for hypertension, whereas lower Lp-PLA2 activity in PLA2G7 279F allele carriers might offer certain protection against hypertension, even in individuals who have been overweight for over three years.
ESTHER : Kim_2017_PLoS.One_12_e0173611
PubMedSearch : Kim_2017_PLoS.One_12_e0173611
PubMedID: 28334001
Gene_locus related to this paper: human-PLA2G7

Title : Biological activity of Myrtaceae plant essential oils and their major components against Drosophila suzukii (Diptera: Drosophilidae) - Jang_2017_Pest.Manag.Sci_73_404
Author(s) : Jang M , Kim J , Yoon KA , Lee SH , Park CG
Ref : Pest Manag Sci , 73 :404 , 2017
Abstract : BACKGROUND: The spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura), is a globally invasive and serious pest of numerous soft-skinned fruit crops. Assessments were made of fumigant and contact toxicities of 12 Myrtaceae plant essential oils (EOs) and their components. For determining the mode of action of major components of active EOs, their activities against acetylcholinesterase (AChE) and Glutathione S-transferase (GST) were also assessed.
RESULTS: Strong fumigant and contact toxicities were observed from EOs of Eucalyptus citriodora and Melaleuca teretifolia. The main components of E. citriodora were citronellal and isopulegol, whereas those of M. teretifolia were neral and geranial. Geranial showed the strongest fumigant activity, followed by citronellal or neral, M. teretifolia EO, isopulegol and E. citriodora EO. In contact toxicity assays, geranial also exhibited the strongest insecticidal activity, followed by neral or M. teretifolia EO, citronellol, citronellal, isopulegol and E. citriodora EO. Among the major components, all compounds showed low AChE inhibitory activity, while neral and geranial showed GST inhibitory activity against SWD. CONCLUSION: Myrtaceae plant EOs and their components have an excellent potential for being used in the control of SWD adults and could be useful in the development of more effective natural compounds as alternatives to synthetic pesticides. (c) 2016 Society of Chemical Industry.
ESTHER : Jang_2017_Pest.Manag.Sci_73_404
PubMedSearch : Jang_2017_Pest.Manag.Sci_73_404
PubMedID: 27607409

Title : Diverse Effects of an Acetylcholinesterase Inhibitor, Donepezil, on Hippocampal Neuronal Death after Pilocarpine-Induced Seizure - Jeong_2017_Int.J.Mol.Sci_18_
Author(s) : Jeong JH , Choi BY , Kho AR , Lee SH , Hong DK , Lee SY , Song HK , Choi HC , Suh SW
Ref : Int J Mol Sci , 18 : , 2017
Abstract : Epileptic seizures are short episodes of abnormal brain electrical activity. Many survivors of severe epilepsy display delayed neuronal death and permanent cognitive impairment. Donepezil is an acetylcholinesterase inhibitor and is an effective treatment agent for Alzheimer's disease. However, the role of donepezil in seizure-induced hippocampal injury remains untested. Temporal lobe epilepsy (TLE) was induced by intraperitoneal injection of pilocarpine (25 mg/kg). Donepezil (2.5 mg/kg/day) was administered by gavage in three different settings: (1) pretreatment for three days before the seizure; (2) for one week immediately after the seizure; and (3) for three weeks from three weeks after the seizure. We found that donepezil showed mixed effects on seizure-induced brain injury, which were dependent on the treatment schedule. Pretreatment with donepezil aggravated neuronal death, oxidative injury, and microglia activation. Early treatment with donepezil for one week showed neither adverse nor beneficial effects; however, a treatment duration of three weeks starting three weeks after the seizure showed a significant reduction in neuronal death, oxidative injury, and microglia activation. In conclusion, donepezil has therapeutic effects when injected for three weeks after seizure activity subsides. Therefore, the present study suggests that the therapeutic use of donepezil for epilepsy patients requires a well-conceived strategy for administration.
ESTHER : Jeong_2017_Int.J.Mol.Sci_18_
PubMedSearch : Jeong_2017_Int.J.Mol.Sci_18_
PubMedID: 29099058

Title : A randomized, placebo-controlled clinical trial evaluating the safety and efficacy of the once-weekly DPP-4 inhibitor omarigliptin in patients with type 2 diabetes mellitus inadequately controlled by glimepiride and metformin - Lee_2017_BMC.Endocr.Disord_17_70
Author(s) : Lee SH , Gantz I , Round E , Latham M , O'Neill EA , Ceesay P , Suryawanshi S , Kaufman KD , Engel SS , Lai E
Ref : BMC Endocr Disord , 17 :70 , 2017
Abstract : BACKGROUND: Type 2 diabetes (T2D) is a progressive disease that often requires a patient to use multiple antihyperglycemic agents to achieve glycemic control with disease progression. Omarigliptin is a once-weekly dipeptidyl peptidase-4 inhibitor. The purpose of this trial was to assess the efficacy and safety of adding omarigliptin to the treatment regimen of patients with T2D inadequately controlled by dual therapy with metformin and glimepiride.
METHODS: Patients with T2D and HbA1c >/=7.5% and <=10.5% while on metformin (>/=1500 mg/day) and glimepiride (>/=4 mg/day) were randomized to omarigliptin 25 mg once-weekly (N = 154) or placebo (N = 153) for 24 weeks. The primary objective was to assess whether omarigliptin was superior to placebo in reducing HbA1c at Week 24. Secondary objectives were to assess the effects of omarigliptin vs. placebo on FPG and the proportion of subjects attaining HbA1c goals of <7% and <6.5%.
RESULTS: From a mean baseline HbA1c of 8.5% (omarigliptin) and 8.6% (placebo), the least squares (LS) mean change from baseline in HbA1c at Week 24 was -0.67% in the omarigliptin group and -0.06% in the placebo group, with a between-group difference (95% CI) of -0.61% (-0.85, -0.38). Treatment with omarigliptin resulted in a significantly greater reduction in FPG relative to placebo (LS mean difference [95% CI] -0.9 mmol/L [-1.4, -0.4]; p < 0.001). The proportion of patients achieving glycemic goals of <7.0% and <6.5% was higher in the omarigliptin group relative to the placebo group. The overall incidences of adverse events (AEs), serious AEs, drug-related AEs and discontinuations were generally similar between treatment groups. The incidence of symptomatic hypoglycemia was 10.5% in the omarigliptin group and 8.5% in the placebo group. Relative to baseline, omarigliptin and placebo treatments were associated with LS mean changes in body weight of -0.1 kg and -0.9 kg, respectively. CONCLUSION: In patients with T2D and inadequate glycemic control on dual therapy with metformin and glimepiride, compared with placebo, once-weekly omarigliptin provided greater improvement in glycemic control and was generally well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01704261 , EudraCT Number: 2012-002612-10. Trial Registration Date: October 8, 2012.
ESTHER : Lee_2017_BMC.Endocr.Disord_17_70
PubMedSearch : Lee_2017_BMC.Endocr.Disord_17_70
PubMedID: 29110647

Title : Invertebrate acetylcholinesterases: Insights into their evolution and non-classical functions - Kim_2017_J.Asia.Pac.Entomol_21_186
Author(s) : Kim YH , Lee SH
Ref : Journal of Asia-Pacific Entomology , 21 :186 , 2017
Abstract : Acetylcholinesterase (AChE) plays a pivotal role in synaptic transmission by hydrolyzing the neurotransmitter acetylcholine. In addition to the classical function of AChE in synaptic transmission, various non-classical functions have been elucidated. Unlike vertebrates possessing a single AChE gene (ace), invertebrates (nematodes, arachnids, and insects) have multiple ace loci, encoding diverse AChEs with a range of different functions. In the field of toxicology, AChE with synaptic function has long been exploited as the target of organophosphorus and cabarmate pesticides to control invertebrate pests for the past several decades. However, many aspects of the evolution and non-classical roles of invertebrate AChEs are still unclear. Although currently available information on invertebrate AChEs is fragmented, we reviewed the recent findings on their evolutionary status, molecular/biochemical properties, and deduced non-classical (non-neuronal) functions.
ESTHER : Kim_2017_J.Asia.Pac.Entomol_21_186
PubMedSearch : Kim_2017_J.Asia.Pac.Entomol_21_186

Title : Expression of acetylcholinesterase 1 is associated with brood rearing status in the honey bee, Apis mellifera - Kim_2017_Sci.Rep_7_39864
Author(s) : Kim YH , Kim JH , Kim K , Lee SH
Ref : Sci Rep , 7 :39864 , 2017
Abstract : Acetylcholinesterase 1 (AmAChE1) of the honey bee, Apis mellifera, has been suggested to have non-neuronal functions. A systematic expression profiling of AmAChE1 over a year-long cycle on a monthly basis revealed that AmAChE1 was predominantly expressed in both head and abdomen during the winter months and was moderately expressed during the rainy summer months. Interestingly, AmAChE1 expression was inhibited when bees were stimulated for brood rearing by placing overwintering beehives in strawberry greenhouses with a pollen diet, whereas it resumed when the beehives were moved back to the cold field, thereby suppressing brood rearing. In early spring, pollen diet supplementation accelerated the induction of brood-rearing activity and the inhibition of AmAChE1 expression. When active beehives were placed in a screen tent in late spring, thereby artificially suppressing brood-rearing activity, AmAChE1 was highly expressed. In contrast, AmAChE1 expression was inhibited when beehives were allowed to restore brood rearing by removing the screen, supporting the hypothesis that brood rearing status is a main factor in the regulation of AmAChE1 expression. Since brood rearing status is influenced by various stress factors, including temperature and diet shortage, our finding discreetly suggests that AmAChE1 is likely involved in the stress response or stress management.
ESTHER : Kim_2017_Sci.Rep_7_39864
PubMedSearch : Kim_2017_Sci.Rep_7_39864
PubMedID: 28045085
Gene_locus related to this paper: apime-ACHE , apime-ACHE1

Title : Cell-sized lipid vesicles for cell-cell synaptic therapies - Vallejo_2017_Technology.(Singap.World.Sci)_5_201
Author(s) : Vallejo D , Lee SH , Lee D , Zhang C , Rapier C , Chessler SD , Lee AP
Ref : Technology (Singap World Sci) , 5 :201 , 2017
Abstract : Cell-sized lipid vesicles (CLVs) have shown great promise for therapeutic and artificial cell applications, but their fragility and short shelf life has hindered widespread adoption and commercial viability. We present a method to circumvent the storage limitations of CLVs such as giant unilamellar vesicles (GUVs) and single-compartment multisomes (SCMs) by storing them in a double emulsion precursor form. The double emulsions can be stored for at least 8 months and readily converted into either GUVs or SCMs at any time. In this study, we investigate the interfacial parameters responsible for this morphological change, and we also demonstrate the therapeutic potential of CLVs by utilizing them to present a transmembrane protein, neuroligin-2, to pancreatic beta-cells, forming cell-cell synapses that stimulate insulin secretion and cellular growth.
ESTHER : Vallejo_2017_Technology.(Singap.World.Sci)_5_201
PubMedSearch : Vallejo_2017_Technology.(Singap.World.Sci)_5_201
PubMedID: 29744376

Title : Effects of dexamethasone coadministered with oseltamivir on the pharmacokinetics of oseltamivir in healthy volunteers - Jang_2017_Drug.Des.Devel.Ther_11_705
Author(s) : Jang K , Kim MK , Oh J , Lee S , Cho JY , Yu KS , Choi TK , Lee SH , Lim KS
Ref : Drug Des Devel Ther , 11 :705 , 2017
Abstract : PURPOSE: Oseltamivir is widely used in the treatment and prophylaxis of influenza A and B viral infections. It is ingested as an oral prodrug that is rapidly metabolized by carboxylesterase 1 (CES1) to its active form, oseltamivir carboxylate. Dexamethasone is also used in the treatment of acute respiratory distress syndrome, a severe complication of influenza; however, its influence on the pharmacokinetics (PK) of oseltamivir is controversial. The aim of this study was to investigate the effects of coadministering oseltamivir and dexamethasone on the PK of oseltamivir in healthy volunteers.
METHODS: An open-label, two-period, one-sequence, multiple-dose study was conducted in 19 healthy male volunteers. Oseltamivir (75 mg) was orally administered on Day 1 and Day 8, and dexamethasone (1.5 mg) was administered once daily from Day 3 to Day 8. Serial blood and urine samples were collected for PK analysis of oseltamivir and oseltamivir carboxylate on Day 1 and Day 8. Oseltamivir and oseltamivir carboxylate concentrations in plasma and urine were determined using liquid chromatography-tandem mass spectrometry.
RESULTS: Area under the plasma concentration-time curve (AUC) of oseltamivir and oseltamivir carboxylate decreased after dexamethasone treatment for 6 days. The geometric mean ratio (90% confidence interval) of the metabolic ratio (oseltamivir carboxylate AUC0-48h/oseltamivir AUC0-48h) was 0.92 (0.87-0.97). The amount of unchanged oseltamivir excreted in urine increased by 14% after dexamethasone treatments. CONCLUSION: Coadministration of dexamethasone with oseltamivir slightly decreased systemic exposure to oseltamivir and oseltamivir carboxylate in healthy volunteers. This result suggests that CES1 is inhibited by dexamethasone in humans. However, coadministration of oseltamivir and dexamethasone did not appear to have a clinically relevant effect on the PK of oseltamivir; based on these results, dexamethasone can be coadministered with oseltamivir.
ESTHER : Jang_2017_Drug.Des.Devel.Ther_11_705
PubMedSearch : Jang_2017_Drug.Des.Devel.Ther_11_705
PubMedID: 28331290

Title : Development of an antibody-based diagnostic method for the identification of Bemisia tabaci biotype B - Baek_2016_Pestic.Biochem.Physiol_131_18
Author(s) : Baek JH , Lee HJ , Kim YH , Lim KJ , Lee SH , Kim BJ
Ref : Pestic Biochem Physiol , 131 :18 , 2016
Abstract : The whitefly Bemisia tabaci is a very destructive pest. B. tabaci is composed of various morphologically undistinguishable biotypes, among which biotypes B and Q, in particular, draw attention because of their wide distribution in Korea and differential potentials for insecticide resistance development. To develop a biotype-specific protein marker that can readily distinguishes biotypes B from other biotypes in the field, we established an ELISA protocol based on carboxylesterase 2 (COE2), which is more abundantly expressed in biotypes B compared with Q. Recombinant COE2 was expressed, purified and used for antibody construction. Polyclonal antibodies specific to B. tabaci COE2 [anti-COE2 pAb and deglycosylated anti-COE2 pAb (DG anti-COE2 pAb)] revealed a 3-9-fold higher reactivity to biotype B COE2 than biotype Q COE2 by Western blot and ELISA analyses. DG anti-COE2 pAb exhibited low non-specific activity, demonstrating its compatibility in diagnosing biotypes. Western blot and ELISA analyses determined that one of the 11 field populations examined was biotype B and the others were biotype Q, suggesting the saturation of biotype Q in Korea. DG anti-COE2 pAb discriminates B. tabaci biotypes B and Q with high specificity and accuracy and could be useful for the development of a B. tabaci biotype diagnosis kit for on-site field applications.
ESTHER : Baek_2016_Pestic.Biochem.Physiol_131_18
PubMedSearch : Baek_2016_Pestic.Biochem.Physiol_131_18
PubMedID: 27265822

Title : (-)-Epicatechin derivate from Orostachys japonicus as potential inhibitor of the human butyrylcholinesterase - Kim_2016_Int.J.Biol.Macromol_91_1033
Author(s) : Kim JH , Lee SH , Lee HW , Sun YN , Jang WH , Yang SY , Jang HD , Kim YH
Ref : Int J Biol Macromol , 91 :1033 , 2016
Abstract : Cholinesterase inhibitors block the bioconversion of neurotransmitters by cholinesterase in the nervous system. Epicatechin derivatives (1, 3 and 5), polyphenols (6 and 7) from Orostachys japonicus, and catechin derivatives (2 and 4) from our in-house library were evaluated for their inhibitory activity on cholinesterase. Compound 5 exhibited IC50 values of 58.3+/-2.4 and 17.8+/-3.8mug/mL on AChE and BuChE, respectively. Compound 5 inhibited BuChE more strongly than AChE through a competitive behavior. In silico binding positions of 5 in the active site were predicted using Autodock 4.2 and processed in a 10000-ps molecular dynamics simulation to assess the stability of compound 5 binding.
ESTHER : Kim_2016_Int.J.Biol.Macromol_91_1033
PubMedSearch : Kim_2016_Int.J.Biol.Macromol_91_1033
PubMedID: 27341781

Title : A novel family VIII carboxylesterase hydrolysing third- and fourth-generation cephalosporins - Jeon_2016_Springerplus_5_525
Author(s) : Jeon JH , Lee HS , Lee JH , Koo BS , Lee CM , Lee SH , Kang SG
Ref : Springerplus , 5 :525 , 2016
Abstract : A metagenomic library was constructed from a soil sample of spindle tree-rhizosphere. From this library, one clone with esterase activity was selected. The sequence analysis revealed an open reading frame (EstSTR1) encoded protein of 390 amino acids. EstSTR1 is a family VIII carboxylesterase and retains the S-X-X-K motif conserved in both family VIII carboxylesterases and class C beta-lactamases. The estSTR1 gene was overexpressed in E. coli and the recombinant protein was purified by purified by metal chelating affinity chromatography and size-exclusion chromatography. EstSTR1 hydrolysed p-nitrophenyl esters, exhibited the highest activity toward p-nitrophenyl butyrate. Furthermore, EstSTR1 could hydrolyse third- and fourth-generation cephalosporins (cefotaxime and cefepime) as well as first-generation cephalosporin (cephalothin). Site-directed mutagenesis studies revealed that a catalytic residue, Ser71, of EstSTR1 plays an essential role in hydrolysing both antibiotics and p-nitrophenyl esters. We demonstrate that a metagenome-derived carboxylesterase displays beta-lactam-hydrolysing activities toward third- and fourth-generation cephalosporins.
ESTHER : Jeon_2016_Springerplus_5_525
PubMedSearch : Jeon_2016_Springerplus_5_525
PubMedID: 27186489

Title : Circulating Lp-PLA activity correlates with oxidative stress and cytokines in overweight\/obese postmenopausal women not using hormone replacement therapy - Paik_2015_Age.(Dordr)_37_32
Author(s) : Paik JK , Kim M , Yen Y , Ahn HY , Lee SH , Lee JH
Ref : Age (Dordr) , 37 :32 , 2015
Abstract : Controversy remains regarding whether there is an association between circulating lipoprotein-associated phospholipase A2 (Lp-PLA2), cytokines, and oxidative stress in healthy postmenopausal women. We investigated the influence of age on Lp-PLA2 activity in postmenopausal women not using hormone therapy and the relationship of Lp-PLA2 enzyme activity to serum cytokine levels and oxidative stress indices. Normal weight (n = 1284) and overweight/obese (n = 707) postmenopausal women not using hormone therapy were categorized into five age groups: 50-54, 55-59, 60-64, 65-69, and 70-89 years. Overweight-obese women showed higher plasma Lp-PLA2 activity, urinary 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha), serum interleukin (IL)-6, and smaller LDL particles than normal-weight women after adjusting for age, years postmenopause, smoking, drinking, blood pressure, glucose, insulin, lipid profiles, BMI, and waist circumference. Overweight/obese women 70-89 years old showed higher Lp-PLA2 activity than those aged 50-54 years, whereas no significant difference in Lp-PLA2 activity existed across normal-weight female age groups. Overweight/obese women aged <= 65 years showed higher Lp-PLA2, oxidized LDL (ox-LDL), IL-6, and 8-epi-PGF2alpha than age-matched normal-weight controls. Overweight/obese women aged <= 70 years had higher ox-LDL levels than those aged 50-59, and overweight/obese women aged 65-89 showed higher IL-6 and 8-epi-PGF2alpha. There were strong positive correlations between Lp-PLA2 and ox-LDL (r = 0.385, P < 0.001), Lp-PLA2 and IL-6 (r = 0.293, P < 0.001), and ox-LDL and IL-6 (r = 0.303, P < 0.001) in overweight/obese women; however, these relationships were weak in normal-weight women. These results suggest that aging and obesity-related oxidative and inflammatory mediators are associated with Lp-PLA2 activity in overweight/obese postmenopausal women not using hormone therapy.
ESTHER : Paik_2015_Age.(Dordr)_37_32
PubMedSearch : Paik_2015_Age.(Dordr)_37_32
PubMedID: 25840804

Title : Identification of a 12-gene Fusaric Acid Biosynthetic Gene Cluster in Fusarium Species Through Comparative and Functional Genomics - Brown_2015_Mol.Plant.Microbe.Interact_28_319
Author(s) : Brown DW , Lee SH , Kim LH , Ryu JG , Lee S , Seo Y , Kim YH , Busman M , Yun SH , Proctor RH , Lee T
Ref : Mol Plant Microbe Interact , 28 :319 , 2015
Abstract : In fungi, genes involved in biosynthesis of a secondary metabolite (SM) are often located adjacent to one another in the genome and are coordinately regulated. These SM biosynthetic gene clusters typically encode enzymes, one or more transcription factors, and a transport protein. Fusaric acid is a polyketide-derived SM produced by multiple species of the fungal genus Fusarium. This SM is of concern because it is toxic to animals and, therefore, is considered a mycotoxin and may contribute to plant pathogenesis. Preliminary descriptions of the fusaric acid (FA) biosynthetic gene (FUB) cluster have been reported in two Fusarium species, the maize pathogen F. verticillioides and the rice pathogen F. fujikuroi. The cluster consisted of five genes and did not include a transcription factor or transporter gene. Here, analysis of the FUB region in F. verticillioides, F. fujikuroi, and F. oxysporum, a plant pathogen with multiple hosts, indicates the FUB cluster consists of at least 12 genes (FUB1 to FUB12). Deletion analysis confirmed that nine FUB genes, including two Zn(II)2Cys6 transcription factor genes, are required for production of wild-type levels of FA. Comparisons of FUB cluster homologs across multiple Fusarium isolates and species revealed insertion of non-FUB genes at one or two locations in some homologs. Although the ability to produce FA contributed to the phytotoxicity of F. oxysporum culture extracts, lack of production did not affect virulence of F. oxysporum on cactus or F. verticillioides on maize seedlings. These findings provide new insights into the genetic and biochemical processes required for FA production.
ESTHER : Brown_2015_Mol.Plant.Microbe.Interact_28_319
PubMedSearch : Brown_2015_Mol.Plant.Microbe.Interact_28_319
PubMedID: 25372119
Gene_locus related to this paper: gibf5-fub4 , gibf5-fub5

Title : Single dose pharmacokinetics of the novel transdermal donepezil patch in healthy volunteers - Kim_2015_Drug.Des.Devel.Ther_9_1419
Author(s) : Kim YH , Choi HY , Lim HS , Lee SH , Jeon HS , Hong D , Kim SS , Choi YK , Bae KS
Ref : Drug Des Devel Ther , 9 :1419 , 2015
Abstract : BACKGROUND: Donepezil is an acetylcholinesterase inhibitor indicated for Alzheimer's disease. The aim of this randomized, single-blind, placebo-controlled, single-dose, dose-escalation study was to investigate the safety, tolerability, and pharmacokinetics of the donepezil patch in healthy male subjects.
METHODS: Each healthy male subject received a single transdermal donepezil patch (72 hours patch-on periods) of 43.75 mg/12.5 cm(2), 87.5 mg/25 cm(2), or 175 mg/50 cm(2). Serial blood samples were collected up to 312 hours after patch application. The plasma concentrations of donepezil were determined by using a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were obtained by noncompartmental analysis. Tolerability of the patches and performance of the patches (adhesion, skin irritation, residual donepezil content in the patch) were assessed throughout the study.
RESULTS: The study was completed by 36 healthy subjects. After patch application, the maximal plasma donepezil concentration (Cmax) and the area under the curve (AUC) increased in a dose-proportional manner. Median time to Cmax was ~74-76 hours (~2-4 hours after patch removal), and mean t1/2beta was ~63.77-93.07 hours. The average donepezil residue in the patch after 72 hours was ~73.9%-86.7% of the loading dose. There were neither serious adverse events nor adverse events that lead to discontinuation. Skin adhesion of the patch was good in 97.2% of the subjects. All skin irritations after patch removal were mild and were resolved during the study period. CONCLUSION: The donepezil patch appeared to be generally well tolerated and adhesive. Pharmacokinetic analysis of the donepezil patch demonstrated linear kinetics.
ESTHER : Kim_2015_Drug.Des.Devel.Ther_9_1419
PubMedSearch : Kim_2015_Drug.Des.Devel.Ther_9_1419
PubMedID: 25792802

Title : Evolutionary origin and status of two insect acetylcholinesterases and their structural conservation and differentiation - Cha_2015_Evol.Dev_17_109
Author(s) : Cha DJ , Lee SH
Ref : Evol Dev , 17 :109 , 2015
Abstract : Acetylcholinesterase (AChE) plays a pivotal role in synaptic transmission in the cholinergic nervous system of most animals, including insects. Insects possess duplicated AChE gene loci (ace1 vs. ace2) encoding two distinct AChEs (AChE1 and AChE2). A phylogenetic analysis suggested that the last common ancestor of two aces shared its origin with Platyhelminthes. In addition, the ace duplication event likely occurred after the divergence of Protostomian but before the split of Ecdysozoa. The ace1 lineage exhibited a significantly lower evolutionary rate (d and dN/dS ratio) than the ace2 lineage, suggesting that the ace1 lineage has retained the essential function of synaptic transmission following its duplication. Therefore, the putative functional transition from ace1 to ace2 observed in some Hymenopteran insects appears to be a local and relatively recent event. The amino acid sequence comparison and three-dimensional modeling of insect AChEs identified a few consistent differences in the amino acid residues in functionally crucial domains between two AChEs, which are likely responsible for the functional differentiation between two AChEs. A unique amino acid substitution causing a dramatic reduction in the catalytic activity of AChE1 in some Hymenopteran insects was suggested to be responsible for the aforementioned functional transition of ace.
ESTHER : Cha_2015_Evol.Dev_17_109
PubMedSearch : Cha_2015_Evol.Dev_17_109
PubMedID: 25627717

Title : Mutation and duplication of arthropod acetylcholinesterase: Implications for pesticide resistance and tolerance - Lee_2015_Pestic.Biochem.Physiol_120_118
Author(s) : Lee SH , Kim YH , Kwon DH , Cha DJ , Kim JH
Ref : Pestic Biochem Physiol , 120 :118 , 2015
Abstract : A series of common/shared point mutations in acetylcholinesterase (AChE) confers resistance to organophosphorus and carbamate insecticides in most arthropod pests. However, the mutations associated with reduced sensitivity to insecticides usually results in the reduction of catalytic efficiency and leads to a fitness disadvantage. To compensate for the reduced catalytic activity, overexpression of neuronal AChE appears to be necessary, which is achieved by a relatively recent duplication of the AChE gene (ace) as observed in the two-spotted spider mite and other insects. Unlike the cases with overexpression of neuronal AChE, the extensive generation of soluble AChE is observed in some insects either from a distinct non-neuronal ace locus or from a single ace locus via alternative splicing. The production of soluble AChE in the fruit fly is induced by chemical stress. Soluble AChE acts as a potential bioscavenger and provides tolerance to xenobiotics, suggesting its role in chemical adaptation during evolution.
ESTHER : Lee_2015_Pestic.Biochem.Physiol_120_118
PubMedSearch : Lee_2015_Pestic.Biochem.Physiol_120_118
PubMedID: 25987229

Title : Genome sequence of mungbean and insights into evolution within Vigna species - Kang_2014_Nat.Commun_5_5443
Author(s) : Kang YJ , Kim SK , Kim MY , Lestari P , Kim KH , Ha BK , Jun TH , Hwang WJ , Lee T , Lee J , Shim S , Yoon MY , Jang YE , Han KS , Taeprayoon P , Yoon N , Somta P , Tanya P , Kim KS , Gwag JG , Moon JK , Lee YH , Park BS , Bombarely A , Doyle JJ , Jackson SA , Schafleitner R , Srinives P , Varshney RK , Lee SH
Ref : Nat Commun , 5 :5443 , 2014
Abstract : Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. Here we construct a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis, which includes several important dietary legumes in Asia, and to enable a better understanding of the evolution of leguminous species. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (V. reflexo-pilosa var. glabra) provides genomic evidence of a recent allopolyploid event. The species tree is constructed using de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.
ESTHER : Kang_2014_Nat.Commun_5_5443
PubMedSearch : Kang_2014_Nat.Commun_5_5443
PubMedID: 25384727
Gene_locus related to this paper: vigrr-a0a1s3ue92 , vigrr-a0a1s3v914 , vigrr-a0a1s3tyf7 , phaan-a0a0s3s998 , vigrr-a0a1s3ux10 , vigrr-a0a1s3ubl0 , vigrr-a0a1s3u036 , vigrr-a0a1s3tul4 , phaan-a0a0l9ujf5 , vigrr-a0a1s3tqd3 , vigrr-a0a1s3udb1 , vigrr-a0a1s3ukc0 , vigrr-a0a1s3ur22 , vigrr-a0a3q0ez52 , vigrr-a0a1s3twy0

Title : Biochemical and toxicological properties of two acetylcholinesterases from the common bed bug, Cimex lectularius - Hwang_2014_Pestic.Biochem.Physiol_110_20
Author(s) : Hwang CE , Kim YH , Kwon DH , Seong KM , Choi JY , Je YH , Lee SH
Ref : Pestic Biochem Physiol , 110 :20 , 2014
Abstract : We examined the molecular and enzymatic properties of two acetylcholinesterases (AChEs; ClAChE1 and ClAChE2) from the common bed bug, Cimex lectularius. Native polyacrylamide gel electrophoresis followed by activity staining and Western blotting revealed that ClAChE1 is the main catalytic enzyme and is abundantly expressed in various tissues. Both ClAChEs existed in dimeric form connected by a disulfide bridge and were attached to the membrane via a glycophosphatidylinositol anchor. To determine their kinetic and inhibitory properties, both ClAChE1 and ClAChE2 were in vitro expressed in Sf9 cells using a baculovirus expression system. ClAChE1 showed higher catalytic efficiency toward acetylcholine, supporting the hypothesis that ClAChE1 plays a major role in postsynaptic transmission. An inhibition assay revealed that ClAChE1 is generally more sensitive to organophosphates and carbamates examined although ClAChE2 was >4000-fold more sensitive to malaoxon than ClAChE1. The relatively higher correlation between the in vitro ClAChE1 inhibition and the in vivo toxicity suggested that ClAChE1 is the more relevant toxicological target for organophosphates and carbamates. Although the physiological function of ClAChE2 remains to be elucidated, ClAChE2 also appears to have neuronal functions, as judged by its tissue distribution and molecular and kinetic properties. Our findings help expand our knowledge on insect AChEs and their toxicological properties.
ESTHER : Hwang_2014_Pestic.Biochem.Physiol_110_20
PubMedSearch : Hwang_2014_Pestic.Biochem.Physiol_110_20
PubMedID: 24759047
Gene_locus related to this paper: cimle-ACHE1 , cimle-ACHE2

Title : Induction of soluble AChE expression via alternative splicing by chemical stress in Drosophila melanogaster - Kim_2014_Insect.Biochem.Mol.Biol_48_75
Author(s) : Kim YH , Kwon DH , Ahn HM , Koh YH , Lee SH
Ref : Insect Biochemistry & Molecular Biology , 48 :75 , 2014
Abstract : Various molecular forms of acetylcholinesterase (AChE) have been characterized in insects. Post-translational modification is known to be a major mechanism for the molecular diversity of insect AChE. However, multiple forms of Drosophila melanogaster AChE (DmAChE) were recently suggested to be generated via alternative splicing (Kim and Lee, 2013). To confirm alternative splicing as the mechanism for generating the soluble form of DmAChE, we generated a transgenic fly strain carrying the cDNA of DmAChE gene (Dm_ace) that predominantly expressed a single transcript variant encoding the membrane-anchored dimer. 3' RACE (rapid amplification of cDNA ends) and western blotting were performed to compare Dm_ace transcript variants and DmAChE forms between wild-type and transgenic strains. Various Dm_ace transcripts and DmAChE molecular forms were observed in wild-type flies, whereas the transgenic fly predominantly expressed Dm_ace transcript variant encoding the membrane-anchored dimer. This supports alternative splicing as the major determinant in the generation of multiple forms of DmAChE. In addition, treatment with DDVP as a chemical stress induced the expression of the Dm_ace splice variant without the glycosylphosphatidylinositol anchor site in a dose-dependent manner and, accordingly, the soluble form of DmAChE in wild-type flies. In contrast, little soluble DmAChE was expressed in the transgenic fly upon exposure to DDVP. DDVP bioassays revealed that transgenic flies, which were unable to express a sufficient amount of soluble monomeric DmAChE, were more sensitive to DDVP compared to wild-type flies, suggesting that the soluble monomer may exert non-neuronal functions, such as chemical defense against xenobiotics.
ESTHER : Kim_2014_Insect.Biochem.Mol.Biol_48_75
PubMedSearch : Kim_2014_Insect.Biochem.Mol.Biol_48_75
PubMedID: 24637386

Title : Identification and characterization of an esterase involved in malathion resistance in the head louse Pediculus humanus capitis - Kwon_2014_Pestic.Biochem.Physiol_112_13
Author(s) : Kwon DH , Kim JH , Kim YH , Yoon KS , Clark JM , Lee SH
Ref : Pestic Biochem Physiol , 112 :13 , 2014
Abstract : Enhanced malathion carboxylesterase (MCE) activity was previously reported to be involved in malathion resistance in the head louse Pediculus humanus capitis (Gao et al., 2006 [8]). To identify MCE, the transcriptional profiles of all five esterases that had been annotated to be catalytically active were determined and compared between the malathion-resistant (BR-HL) and malathion-susceptible (KR-HL) strains of head lice. An esterase gene, designated HLCbE3, exhibited approximately 5.4-fold higher transcription levels, whereas remaining four esterases did not exhibit a significant increase in their transcription in BR-HL, indicating that HLCbE3 may be the putative MCE. Comparison of the entire cDNA sequences of HLCbE3 revealed no sequence differences between the BR-HL and KR-HL strains and suggested that no single nucleotide polymorphism is associated with enhanced MCE activity. Two copies of the HLCbE3 gene were observed in BR-HL, implying that the over-transcription of HLCbE3 is due to the combination of a gene duplication and up-regulated transcription. Knockdown of HLCbE3 expression by RNA interference in the BR-HL strain led to increases in malathion susceptibility, confirming the identity of HLCbE3 as a MCE responsible for malathion resistance in the head louse. Phylogenetic analysis suggested that HLCbE3 is a typical dietary esterase and belongs to a clade containing various MCEs involved in malathion resistance.
ESTHER : Kwon_2014_Pestic.Biochem.Physiol_112_13
PubMedSearch : Kwon_2014_Pestic.Biochem.Physiol_112_13
PubMedID: 24974112

Title : Ramlibacter solisilvae sp. nov., isolated from forest soil, and emended description of the genus Ramlibacter - Lee_2014_Int.J.Syst.Evol.Microbiol_64_1317
Author(s) : Lee HJ , Lee SH , Lee SS , Lee JS , Kim Y , Kim SC , Jeon CO
Ref : Int J Syst Evol Microbiol , 64 :1317 , 2014
Abstract : A Gram-staining-negative, strictly aerobic, white-colony-forming bacterium, designated strain 5-10(T), was isolated from forest soil of Bac Kan Province in Vietnam. Cells were non-motile rods or coccoids, showing oxidase- and catalase-positive reactions. Growth was observed at 10-37 degrees C (optimum, 30 degrees C), at pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-1.0 % (w/v) NaCl (optimum, 0-0.5 %). The major cellular fatty acids were summed feature 3 (comprising C16 : 1omega6c and/or C16 : 1omega7c), C16 : 0, C10 : 0 3-OH and summed feature 8 (comprising C18 : 1omega6c and/or C18 : 1omega7c). The G+C content of the genomic DNA was 69.9 mol% and the only respiratory quinone detected was ubiquinone 8 (Q-8). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 5-10(T) formed a tight phyletic lineage with members of the genus Ramlibacter. Strain 5-10(T) was most closely related to Ramlibacter tataouinensis TTB310(T) (97.3 %), but the DNA-DNA relatedness level between the two strains was 38.2+/-1.8 %. Based on phenotypic, chemotaxonomic and molecular features, strain 5-10(T) was shown to represent a novel species of the genus Ramlibacter, for which the name Ramlibacter solisilvae sp. nov. is proposed. The type strain is 5-10(T) ( = KACC 17567(T) = JCM 19319(T)). An emended description of the genus Ramlibacter is also proposed.
ESTHER : Lee_2014_Int.J.Syst.Evol.Microbiol_64_1317
PubMedSearch : Lee_2014_Int.J.Syst.Evol.Microbiol_64_1317
PubMedID: 24425747
Gene_locus related to this paper: 9burk-a0a127juv8

Title : Inhibition of acetylcholinesterases of the pinewood nematode, Bursaphelenchus xylophilus, by phytochemicals from plant essential oils - Kang_2013_Pestic.Biochem.Physiol_105_50
Author(s) : Kang JS , Kim E , Lee SH , Park IK
Ref : Pesticide Biochemistry and Physiology , 105 :50 , 2013
Abstract : To understand the nematicidal mode of action of phytochemicals derived from plant essential oils against the pinewood nematode (Bursaphelenchus xylophilus), we evaluated 97 compounds (49 monoterpenes, 17 phenylpropenes, 16 sesquiterpenes, and 15 sulfides) for their inhibitory effects on B. xylophilus acetylcholinesterases (BxACEs). In the primary inhibition assay using B. xylophilus crude protein, more than 50% BxACE inhibition activity was observed with 3 monoterpenes, (+)-alpha-pinene, (-)-alpha-pinene, and 3-carene; 2 phenylpropenes, omicron-anisaldehyde, and coniferyl alcohol; and 1 sesquiterpene, cis-nerolidol. Other compounds showed moderate or weak inhibitory activity. The inhibitory activities against 3 recombinant BxACEs were subsequently estimated using the identified active compounds in a primary inhibition assay. (+)-alpha-Pinene showed the strongest inhibition of BxACE-1 followed by 3-carene, coniferyl alcohol, (-)-alpha-pinene, o-anisaldehyde, and cis-nerolidol. The half maximal inhibitory concentration (IC50) values of (+)-alpha-pinene, 3-carene, o-anisaldehyde, cis-nerolidol, and (-)-alpha-pinene against BxACE-2 were found to be 0.64, 1.41, 8.18, 8.53, 15.28, and 18.03mM, respectively. Coniferyl alcohol showed the strongest inhibition of BxACE-3 followed by (+)-alpha-pinene and cis-nerolidol.
ESTHER : Kang_2013_Pestic.Biochem.Physiol_105_50
PubMedSearch : Kang_2013_Pestic.Biochem.Physiol_105_50
PubMedID: 24238290
Gene_locus related to this paper: burxy-ACHE1 , burxy-ACHE2 , burxy-ACHE3

Title : Which acetylcholinesterase functions as the main catalytic enzyme in the Class Insecta? - Kim_2013_Insect.Biochem.Mol.Biol_43_47
Author(s) : Kim YH , Lee SH
Ref : Insect Biochemistry & Molecular Biology , 43 :47 , 2013
Abstract : Most insects possess two different acetylcholinesterases (AChEs) (i.e., AChE1 and AChE2; encoded by ace1 and ace2 genes, respectively). Between the two AChEs, AChE1 has been proposed as a major catalytic enzyme based on its higher expression level and frequently observed point mutations associated with insecticide resistance. To investigate the evolutionary distribution of AChE1 and AChE2, we determined which AChE had a central catalytic function in several insect species across 18 orders. The main catalytic activity in heads was determined by native polyacrylamide gel electrophoresis in conjunction with Western blotting using AChE1- and AChE2-specific antibodies. Of the 100 insect species examined, 67 species showed higher AChE1 activity; thus, AChE1 was considered as the main catalytic enzyme. In the remaining 33 species, ranging from Palaeoptera to Hymenoptera, however, AChE2 was predominantly expressed as the main catalytic enzyme. These findings challenge the common notion that AChE1 is the only main catalytic enzyme in insects with the exception of Cyclorrhapha, and further demonstrate that the specialization of AChE2 as the main enzyme or the replacement of AChE1 function with AChE2 were rather common events, having multiple independent origins during insect evolution. It was hypothesized that the generation of multiple AChE2 isoforms by alternative splicing allowed the loss of ace1 during the process of functional replacement of AChE1 with AChE2 in Cyclorrhapha. However, the presence of AChE2 as the main catalytic enzyme in higher social Hymenoptera provides a case for the functional replacement of AChE1 with AChE2 without the loss of ace1. The current study will provide valuable insights into the evolution of AChE: which AChE has been specialized as the main catalytic enzyme and to become the main target for insecticides in different insect species.
ESTHER : Kim_2013_Insect.Biochem.Mol.Biol_43_47
PubMedSearch : Kim_2013_Insect.Biochem.Mol.Biol_43_47
PubMedID: 23168079

Title : Expression of a lipase on the cell-surface of Escherichia coli using the OmpW anchoring motif and its application to enantioselective reactions - Lee_2013_Biotechnol.Lett_35_1677
Author(s) : Lee H , Park SJ , Han MJ , Eom GT , Choi MJ , Kim SH , Oh YH , Song BK , Lee SH
Ref : Biotechnol Lett , 35 :1677 , 2013
Abstract : Microbial-surface display is the expression of proteins or peptides on the surface of cells by fusing an appropriate protein as an anchoring motif. Here, the outer membrane protein W (OmpW) was selected as a fusion partner for functional expression of Pseudomonas fluorescence SIK W1 lipase (TliA) on the cell-surface of Escherichia coli. Localization of the truncated OmpW-TliA fusion protein on the cell-surface was confirmed by immunoblotting and functional assay of lipase activity. Enantioselective hydrolysis of rac-phenylethyl butanoate by the displayed lipase resulted in optically active (R)-phenyl ethanol with 96 % enantiomeric excess and 44 % of conversion in 5 days. Thus, a small outer membrane protein OmpW, is a useful anchoring motif for displaying an active enzyme of ~50 kDa on the cell-surface and the surface-displayed lipase can be employed as an enantioselective biocatalyst in organic synthesis.
ESTHER : Lee_2013_Biotechnol.Lett_35_1677
PubMedSearch : Lee_2013_Biotechnol.Lett_35_1677
PubMedID: 23881313

Title : Biochemical characterization of two distinct acetylcholinesterases possessing almost identical catalytic activity in the damselfly Vestalis gracilis - Kim_2013_J.Asia.Pac.Entomol_16_465
Author(s) : Kim YH , Kwon DH , Lee SH
Ref : Journal of Asia-Pacific Entomology , 16 :465 , 2013
Abstract : Most insects possess two different acetylcholinesterases (AChEs) (i.e., AChE1 and AChE2). It has been recently reported that only one AChE (either AChE1 or AChE2) has been selected as the main synaptic enzyme and it varies with different insect lineages (Kim et al., 2012 and Kim and Lee, 2013). Interestingly, however, both AChE1 and AChE2 are almost equally active in a damselfly species, providing a unique example of the incomplete specialization of one AChE function after duplication, where, consequently, both AChE1 and AChE2 likely play a similar role in synaptic transmission. In this study, therefore, we investigated the tissue distribution patterns and the molecular and inhibitory properties of two AChEs (i.e., VgAChE1 and VgAChE2) from the Vestalis gracilis damselfly as a model species possessing two AChEs that are equally active. VgAChEs exhibited almost identical catalytic activity and were expressed in the central nervous system (CNS). The most predominant molecular form of both VgAChEs was a disulfide-bridged dimer, which is associated with the cell membrane via a glycosylphosphatidylinositol anchor. In an inhibition assay, however, VgAChE1 and VgAChE2 exhibited different sensitivities to organophosphate and carbamate insecticides depending on the structure of the inhibitors. These findings suggest that both VgAChEs have neuronal functions. In addition, soluble monomeric and cleaved molecular forms were detected in both the CNS and peripheral nervous system tissues by an AChE2-specific antibody, implying that VgAChE2 probably shares both neuronal and non-neuronal physiological functions in V. gracilis. Our results support the notion that both VgAChEs, paralogous of each other, are involved in synaptic transmission, with VgAChE2 being in the early stage of acquiring non-neuronal functions.
ESTHER : Kim_2013_J.Asia.Pac.Entomol_16_465
PubMedSearch : Kim_2013_J.Asia.Pac.Entomol_16_465

Title : Superpriming of synaptic vesicles after their recruitment to the readily releasable pool - Lee_2013_Proc.Natl.Acad.Sci.U.S.A_110_15079
Author(s) : Lee JS , Ho WK , Neher E , Lee SH
Ref : Proc Natl Acad Sci U S A , 110 :15079 , 2013
Abstract : Recruitment of release-competent vesicles during sustained synaptic activity is one of the major factors governing short-term plasticity. During bursts of synaptic activity, vesicles are recruited to a fast-releasing pool from a reluctant vesicle pool through an actin-dependent mechanism. We now show that newly recruited vesicles in the fast-releasing pool do not respond at full speed to a strong Ca(2+) stimulus, but require approximately 4 s to mature to a "superprimed" state. Superpriming was found to be altered by agents that modulate the function of unc13 homolog proteins (Munc13s), but not by calmodulin inhibitors or actin-disrupting agents. These findings indicate that recruitment and superpriming of vesicles are regulated by separate mechanisms, which require integrity of the cytoskeleton and activation of Munc13s, respectively. We propose that refilling of the fast-releasing vesicle pool proceeds in two steps, rapid actin-dependent "positional priming," which brings vesicles closer to Ca(2+) sources, followed by slower superpriming, which enhances the Ca(2+) sensitivity of primed vesicles.
ESTHER : Lee_2013_Proc.Natl.Acad.Sci.U.S.A_110_15079
PubMedSearch : Lee_2013_Proc.Natl.Acad.Sci.U.S.A_110_15079
PubMedID: 23980146

Title : Metabolic engineering of Ralstonia eutropha for the biosynthesis of 2-hydroxyacid-containing polyhydroxyalkanoates - Park_2013_Metab.Eng_20_20
Author(s) : Park SJ , Jang YA , Lee H , Park AR , Yang JE , Shin J , Oh YH , Song BK , Jegal J , Lee SH , Lee SY
Ref : Metab Eng , 20 :20 , 2013
Abstract : Polyhydroxyalkanoates (PHAs) are bio-based and biodegradable polyesters synthesized by numerous microorganisms. PHAs containing 2-hydroxyacids as monomer units have attracted much attention, but their production has not been efficient. Here, we metabolically engineered Ralstonia eutropha strains for the in vivo synthesis of PHAs containing 2-hydroxyacids as monomers. This was accomplished by replacing the R. eutropha phaC gene in the chromosome with either the R. eutropha phaC S506G A510K gene, which contains two point mutations, or the Pseudomonas sp. MBEL 6-19 phaC1437 gene. In addition, the R. eutropha phaAB genes in the chromosome were replaced with the Clostridium propionicum pct540 gene. All of the engineered R. eutropha strains produced PHAs containing 2-hydroxyacid monomers, including lactate and 2-hydroxybutyrate (2HB), along with 3-hydroxybutyrate (3HB) and/or 3-hydroxyvalerate (3HV), when they were cultured in nitrogen-free medium containing 5 g/L lactate or 4 g/L 2HB and 20 g/L glucose as carbon sources. Expression of the Escherichia coli ldhA gene in engineered R. eutropha strains allowed production of poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] from glucose as the sole carbon source. This is the first report on the production of 2-hydroxyacid-containing PHAs by metabolically engineered R. eutropha.
ESTHER : Park_2013_Metab.Eng_20_20
PubMedSearch : Park_2013_Metab.Eng_20_20
PubMedID: 23973656

Title : The overexpression of acetylcholinesterase compensates for the reduced catalytic activity caused by resistance-conferring mutations in Tetranychus urticae - Kwon_2012_Insect.Biochem.Mol.Biol_42_212
Author(s) : Kwon DH , Choi JY , Je YH , Lee SH
Ref : Insect Biochemistry & Molecular Biology , 42 :212 , 2012
Abstract : The mutations (G228S, A391T and F439W) and duplication of the acetylcholinesterase (AChE) gene (Tuace) are involved in monocrotophos resistance in the two-spotted spider mites, Tetranychus urticae (Kwon et al., 2010a, b). The overexpression of T. urticae AChE (TuAChE) as a result of Tuace duplication was confirmed in several field-collected populations by Western blotting using an AChE-specific antibody. To investigate the effects of each mutation on the insensitivity and fitness cost of AChE, eight variants of TuAChE were expressed in vitro using the baculovirus expression system. Kinetic analysis revealed that the G228S and F439W mutations confer approximately 26-fold and 99-fold increases in the insensitivity to monocrotophos, respectively, whereas the insensitivity increased over 1165-fold in the AChE with double mutations. Nevertheless, the presence of these mutations reduced the catalytic efficiency of AChE significantly. In particular, the TuAChE having both mutations together exhibited a 17.8 approximately 27.1-fold reduced catalytic efficiency, suggesting an apparent fitness cost in the monocrotophos-resistant mites. The A391T mutation did not change the kinetic properties of either the substrate or inhibitor when present alone but mitigated the negative impacts of the F439 mutation. To simulate the catalytic activity of the overexpressed TuAChE in two T. urticae strains (approximately 6 copies for AD strain vs. 2 copies for PyriF strain), appropriate TuAChE variants were combined to make up the desired AChE copies and mutation frequencies, and their enzyme kinetics were determined. The reconstituted 6-copy and 2-copy TuAChEs exhibited catalytic efficiency levels comparable to those of a single-copy wildtype TuAChE, suggesting that, if mutations are present, multiple copies of AChE are required to restore a normal level of catalytic activity in the monocrotophos-resistant mites. In summary, the present study provides clear evidence that Tuace duplication resulted in the proportional overexpression of AChE, which was necessary to compensate for the reduced catalytic activity of AChE caused by mutations.
ESTHER : Kwon_2012_Insect.Biochem.Mol.Biol_42_212
PubMedSearch : Kwon_2012_Insect.Biochem.Mol.Biol_42_212
PubMedID: 22198354
Gene_locus related to this paper: tetur-ACHE

Title : Complete genome sequence of the BTEX-degrading bacterium Pseudoxanthomonas spadix BD-a59 - Lee_2012_J.Bacteriol_194_544
Author(s) : Lee SH , Jin HM , Lee HJ , Kim JM , Jeon CO
Ref : Journal of Bacteriology , 194 :544 , 2012
Abstract : Pseudoxanthomonas spadix BD-a59, able to metabolize all six BTEX (benzene, toluene, ethylbenzene, and o-, m-, and p-xylene) compounds, was isolated from gasoline-contaminated sediment. Here, we report the complete 3.45-Mb genome sequence and annotation of strain BD-a59. These advance the understanding of strain BD-a59's genomic properties and pollutant metabolic versatility.
ESTHER : Lee_2012_J.Bacteriol_194_544
PubMedSearch : Lee_2012_J.Bacteriol_194_544
PubMedID: 22207748
Gene_locus related to this paper: pseup-g7unl8 , pseup-g7uu78

Title : Identification and characterization of three cholinesterases from the common bed bug, Cimex lectularius - Seong_2012_Insect.Mol.Biol_21_149
Author(s) : Seong KM , Kim YH , Kwon DH , Lee SH
Ref : Insect Molecular Biology , 21 :149 , 2012
Abstract : We identified and characterized the full-length cDNA sequences encoding two acetylcholinesterases (ClAChE1 and ClAChE2) and a salivary gland-specific cholinesterase-like protein (ClSChE) from the common bed bug, Cimex lectularius. All three cholinesterase genes (Clac1, Clace2 and Clsce) have conserved motifs, including a catalytic triad, a choline-binding site and an acyl pocket. Phylogenetic analysis showed that ClAChE1 belongs to the insect AChE1 clade, whereas ClAChE2 belongs to the insect AChE2 clade. ClSChE was grouped into the clade containing all AChE1s, suggesting a paralogous relationship to ClAChE1. Transcription levels of Clace1 were higher than those of Clace2 in all tissues examined, including the central nervous system (CNS). In contrast, the Clsce transcript was not detected in the CNS but specifically found in the salivary gland at much higher levels (>3000-fold) than those of Clace1 and Clace2. Western blot analysis using anti-ClAChE antibodies, in conjunction with activity staining, revealed that ClAChE1 is more active than ClAChE2, whereas ClSChE has little enzyme activity. Three-dimensional structure modelling suggested that ClAChEs and ClSChE shared structural similarities, but had some differences in the residues forming the acyl pocket and oxyanion hole. The current findings should provide valuable insights into the evolution and functional diversification of insect cholinesterase.
ESTHER : Seong_2012_Insect.Mol.Biol_21_149
PubMedSearch : Seong_2012_Insect.Mol.Biol_21_149
PubMedID: 22136067
Gene_locus related to this paper: cimle-ACHE1 , cimle-ACHE2 , cimle-d1fqg8

Title : Cloning of the acetylcholinesterase 1 gene and identification of point mutations putatively associated with carbofuran resistance in Nilaparvata lugens - Kwon_2012_Pestic.Biochem.Physiol_103_94
Author(s) : Kwon DH , Cha DJ , Kim YH , Lee SW , Lee SH
Ref : Pesticide Biochemistry and Physiology , 103 :94 , 2012
Abstract : Molecular mechanisms of carbofuran resistance in the brown planthopper, Nilaparvata lugens Stl, were investigated. A carbofuran-resistant strain (CAS) showed approximately 45.5- and 15.1-fold resistance compared with a susceptible strain (SUS) and a non-selected field strain (FM), respectively. Activities of the esterase and mixed-function oxidase were approximately 2.8- and 1.6-fold higher, respectively, in the CAS strain than in the SUS strain, suggesting that these enzymes play a minor role in carbofuran resistance. Interestingly, the insensitivity of acetylcholinesterase (AChE) to carbofuran was approximately 5.5- and 3.7-fold higher in the CAS strain compared to the SUS and FM strains, respectively, indicating that AChE insensitivity is associated with carbofuran resistance. Western blot analysis identified two kinds of AChEs, of which the type-1 AChE (encoded from Nlace1, which is paralogous to the Drosophila AChE gene) was determined to be the major catalytic AChE in N. lugens. The open reading frame of Nlace1 is composed of 1989 bp (approximately 74 kD) and revealed 52.5% and 24.3% amino acid sequence identities to those of Nephotettix cincticeps and Drosophila melanogaster, respectively. Screening of point mutations identified four amino acid substitutions (G119A, F/Y330S, F331H and H332L) in the CAS strain that likely contribute to AChE insensitivity. The frequencies of these mutations were well correlated with resistance levels, confirming that they are associated with reduced sensitivity to carbofuran in N. lugens. These point mutations can be useful as genetic markers for monitoring resistance levels in field populations of N. lugens.
ESTHER : Kwon_2012_Pestic.Biochem.Physiol_103_94
PubMedSearch : Kwon_2012_Pestic.Biochem.Physiol_103_94
Gene_locus related to this paper: nillu-ACHE1

Title : Inhibition properties of three acetylcholinesterases of the pinewood nematode Bursaphelenchus xylophilus by organophosphates and carbamates - Kang_2012_Pestic.Biochem.Physiol_104_157
Author(s) : Kang JS , Moon YS , Lee SH
Ref : Pesticide Biochemistry and Physiology , 104 :157 , 2012
Abstract : The pinewood nematode, Bursaphelenchus xylophilus, causes severe damage to pine species by transmitting the pine wilt disease, and the injection of nematicides, such as emamectin benzonate and milbemectin, is the most common practice to control this pest. However, despite their high efficacy, these macrocyclic lactone nematicides are expensive, limiting their practicability. In an attempt to screen affordable alternative nematicidal agents, we expressed three recombinant acetylcholinesterases (ACEs, EC of B. xylophilus using an in vitro baculovirus expression system and evaluated the effects of 11 organophosphates (OPs) and three carbamates (CBs) on the toxicological properties of the enzymes. Of the three recombinant B. xylophilus ACEs (BxACEs; BxACE-1, BxACE-2 and BxACE-3), BxACE-1 and BxACE-2 were highly inhibited by OPs and CBs, including paraoxon, dichlorvos, chlorpyrifos-oxon, chlorpyrifos-methyl-oxon, mevinphos and carbofuran, as demonstrated by an inhibition assay. In contrast, BxACE-3 was insensitive to most of the pesticides tested, with the exception of mevinphos. BxACE-2 was more sensitive than BxACE-1 and BxACE-3 to most of the OPs, whereas BxACE-1 was more sensitive to the CBs than BxACE-2 and BxACE-3. An in vivo toxicity assay revealed that some compounds that were rarely employed as nematicides exhibited higher toxicities than those chemicals commonly used as nematicides. The inhibition kinetic data and in vivo toxicity assay obtained in this study should provide essential information for the development of OP- and CB-based nematicides against B. xylophilus. The availability of recombinant ACEs will also facilitate the development of an in vitro screening system to develop potential OP- and CB-based nematicides.
ESTHER : Kang_2012_Pestic.Biochem.Physiol_104_157
PubMedSearch : Kang_2012_Pestic.Biochem.Physiol_104_157
Gene_locus related to this paper: burxy-ACHE1 , burxy-ACHE2 , burxy-ACHE3

Title : A cellular model of memory reconsolidation involves reactivation-induced destabilization and restabilization at the sensorimotor synapse in Aplysia - Lee_2012_Proc.Natl.Acad.Sci.U.S.A_109_14200
Author(s) : Lee SH , Kwak C , Shim J , Kim JE , Choi SL , Kim HF , Jang DJ , Lee JA , Lee K , Lee CH , Lee YD , Miniaci MC , Bailey CH , Kandel ER , Kaang BK
Ref : Proc Natl Acad Sci U S A , 109 :14200 , 2012
Abstract : The memory reconsolidation hypothesis suggests that a memory trace becomes labile after retrieval and needs to be reconsolidated before it can be stabilized. However, it is unclear from earlier studies whether the same synapses involved in encoding the memory trace are those that are destabilized and restabilized after the synaptic reactivation that accompanies memory retrieval, or whether new and different synapses are recruited. To address this issue, we studied a simple nonassociative form of memory, long-term sensitization of the gill- and siphon-withdrawal reflex in Aplysia, and its cellular analog, long-term facilitation at the sensory-to-motor neuron synapse. We found that after memory retrieval, behavioral long-term sensitization in Aplysia becomes labile via ubiquitin/proteasome-dependent protein degradation and is reconsolidated by means of de novo protein synthesis. In parallel, we found that on the cellular level, long-term facilitation at the sensory-to-motor neuron synapse that mediates long-term sensitization is also destabilized by protein degradation and is restabilized by protein synthesis after synaptic reactivation, a procedure that parallels memory retrieval or retraining evident on the behavioral level. These results provide direct evidence that the same synapses that store the long-term memory trace encoded by changes in the strength of synaptic connections critical for sensitization are disrupted and reconstructed after signal retrieval.
ESTHER : Lee_2012_Proc.Natl.Acad.Sci.U.S.A_109_14200
PubMedSearch : Lee_2012_Proc.Natl.Acad.Sci.U.S.A_109_14200
PubMedID: 22893682

Title : Learning-related synaptic growth mediated by internalization of Aplysia cell adhesion molecule is controlled by membrane phosphatidylinositol 4,5-bisphosphate synthetic pathway - Lee_2012_J.Neurosci_32_16296
Author(s) : Lee SH , Shim J , Choi SL , Lee N , Lee CH , Bailey CH , Kandel ER , Jang DJ , Kaang BK
Ref : Journal of Neuroscience , 32 :16296 , 2012
Abstract : Long-term facilitation in Aplysia is accompanied by the growth of new synaptic connections between the sensory and motor neurons of the gill-withdrawal reflex. One of the initial steps leading to the growth of these synapses is the internalization, induced by 5-HT, of the transmembrane isoform of Aplysia cell-adhesion molecule (TM-apCAM) from the plasma membrane of sensory neurons (Bailey et al., 1992). However, the mechanisms that govern the internalization of TM-apCAM and how this internalization is coupled to the molecular events that initiate the structural changes are not fully understood. Here, we report that the synthesis of membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)], which is known to be mediated by a signaling cascade through Aplysia Sec7 protein (ApSec7) and phosphatidylinositol-4-phosphate 5-kinase type I alpha (PIP5KIalpha) is required for both the internalization of TM-apCAM and the initiation of synaptic growth during 5-HT-induced long-term facilitation. Pharmacological blockade of PI(4,5)P(2) synthesis by the application of the inhibitor phenylarsine oxide blocked the internalization of apCAM. Furthermore, perturbation of the endogenous activation of ApSec7 and its downstream target PIP5KIalpha also blocked 5-HT-mediated internalization of TM-apCAM and synaptic growth. Finally, long-term facilitation was specifically impaired by blocking the ApSec7 signaling pathway at sensory-to-motor neuron synapses. These data indicate that the ApSec7/PIP5KIalpha signaling pathway is actively recruited during learning-related 5-HT signaling and acts as a key regulator of apCAM internalization associated with the formation of new synaptic connections during long-term facilitation.
ESTHER : Lee_2012_J.Neurosci_32_16296
PubMedSearch : Lee_2012_J.Neurosci_32_16296
PubMedID: 23152613

Title : Complete genome sequence of Leuconostoc mesenteroides subsp. mesenteroides strain J18, isolated from kimchi - Jung_2012_J.Bacteriol_194_730
Author(s) : Jung JY , Lee SH , Jeon CO
Ref : Journal of Bacteriology , 194 :730 , 2012
Abstract : Leuconostoc mesenteroides subsp. mesenteroides is one of the most predominant lactic acid bacterial groups during kimchi fermentation. Here, we report the complete genome sequence of L. mesenteroides subsp. mesenteroides J18, which was isolated from kimchi. The genome of the strain consists of a 1,896,561-bp chromosome and five plasmids.
ESTHER : Jung_2012_J.Bacteriol_194_730
PubMedSearch : Jung_2012_J.Bacteriol_194_730
PubMedID: 22247530
Gene_locus related to this paper: leumm-q03y60 , leume-a0a0n1s1e2

Title : Molecular and kinetic properties of two acetylcholinesterases from the western honey bee, Apis mellifera - Kim_2012_PLoS.One_7_e48838
Author(s) : Kim YH , Cha DJ , Jung JW , Kwon HW , Lee SH
Ref : PLoS ONE , 7 :e48838 , 2012
Abstract : We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC(50) values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, a significant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.
ESTHER : Kim_2012_PLoS.One_7_e48838
PubMedSearch : Kim_2012_PLoS.One_7_e48838
PubMedID: 23144990
Gene_locus related to this paper: apime-ACHE , apime-ACHE1

Title : Mutation in ace1 associated with an insecticide resistant population of Plutella xylostella - Kim_2012_J.Asia.Pac.Entomol_15_401
Author(s) : Kim JI , Joo YR , Kwon M , Kim GH , Lee SH
Ref : Journal of Asia-Pacific Entomology , 15 :401 , 2012
Abstract : Insensitive acetylcholinesterase (AChE) was determined to be involved in an EPN-resistant (ER) strain and a contaminated susceptible (CS) strain of diamondback moth (DBM, Plutella xylostella L.), as estimated by AChE inhibition assay using DDVP as a inhibitor in a nondenaturing electrophoresis gel. The ER strain exhibited very high AChE insensitivity, high resistance ratio, and two point mutations (G324A, A298S) in ace1-type AChE gene (Pxace1). The CS strain showed low AChE insensitivity, low resistance ratio, and it has only one point mutation (G324A). These findings suggest that the A298S mutation, along with reported G324A mutation (Baek et al, 2005), can be important in the development of organophosphate resistance. These results also suggest that the A298S mutation could be a good candidate for a molecular diagnosis marker for resistance monitoring. Three molecular diagnosis methods (Quantitative Sequencing; QS, PCR amplification of specific alleles; PASA and restriction fragment length polymorphism; RFLP) were developed which successfully detected specific resistance associated point mutations. Seven local population DBMs were surveyed and showed high insecticide resistance levels and a A298S mutation in Pxace1. These methods can be used to monitor the resistance allele in field population of DBMs and resistance management strategy.
ESTHER : Kim_2012_J.Asia.Pac.Entomol_15_401
PubMedSearch : Kim_2012_J.Asia.Pac.Entomol_15_401

Title : Draft genome sequence of Salimicrobium sp. strain MJ3, isolated from Myulchi-Jeot, Korean fermented seafood - Lee_2012_J.Bacteriol_194_6695
Author(s) : Lee SH , Jung JY , Jeon CO
Ref : Journal of Bacteriology , 194 :6695 , 2012
Abstract : Salimicrobium sp. strain MJ3 was isolated from myulchi-jeot, traditional fermented seafood made from anchovy in South Korea. Here we announce the draft genome sequence of Salimicrobium sp. MJ3 with 2,717,782 bp, which consists of 45 contigs (>500 bp in size), and provide a description of their annotation.
ESTHER : Lee_2012_J.Bacteriol_194_6695
PubMedSearch : Lee_2012_J.Bacteriol_194_6695
PubMedID: 23144427
Gene_locus related to this paper: 9baci-k2gdv4 , 9baci-k2hbp5

Title : Proteomics-based identification and characterization of biotype-specific carboxylesterase 2 putatively associated with insecticide resistance in Bemisia tabaci - Kang_2012_J.Asia.Pac.Entomol_15_389
Author(s) : Kang S , Lee HJ , Kim YH , Kwon DH , Oh JH , Kim BJ , Lim KJ , Lee S , Hwang SY , Lee SH
Ref : Journal of Asia-Pacific Entomology , 15 :389 , 2012
Abstract : Proteomic differences between Bemisia tabaci biotypes (B and Q) were investigated by two-dimensional gel electrophoresis in conjunction with mass spectroscopic analysis. Among several protein spots specific to biotype B, carboxylesterase 2 (Coe2) was significantly more expressed in biotype B. Phylogenetic analysis demonstrated the close relationship of Coe2 with Myzus persicae esterase E4. Comparison of full-length cDNA sequences of Coe2 revealed no amino acid differences in functionally important conserved regions between biotypes B and Q. The transcription level of the Coe2 gene (coe2) was 5.8-fold higher in biotype B than in biotype Q, but the coe2 copy number was not different between biotypes, suggesting that the overexpression of Coe2 was due to transcriptional up-regulation. Native isoelectric focusing followed by mass spectrophotometric analysis confirmed that the overexpressed pI 5.7 esterase in biotype B was Coe2. In-gel inhibition of Coe2 by three insecticides indicated the interaction of Coe2 with chlorpyrifos-methyl oxon and permethrin, but not with imidacloprid. These findings suggest that overexpression of Coe2 in biotype B can confer chemical defense against pyrethroid and organophosphate insecticides, perhaps by sequestration and hydrolysis, as seen in M. persicae E4. Finally, utility of Coe2 as a potential biotype-specific protein marker is discussed.
ESTHER : Kang_2012_J.Asia.Pac.Entomol_15_389
PubMedSearch : Kang_2012_J.Asia.Pac.Entomol_15_389

Title : Complete genome sequence of Leuconostoc gelidum strain JB7, isolated from kimchi - Jung_2012_J.Bacteriol_194_6665
Author(s) : Jung JY , Lee SH , Jeon CO
Ref : Journal of Bacteriology , 194 :6665 , 2012
Abstract : A strain of Leuconostoc gelidum, designated strain JB7, was isolated from kimchi, the representative Korean traditional fermented food. Here we announce the complete genome sequence of L. gelidum strain JB7, consisting of a 1,893,499-bp circular chromosome with a G+C content of 36.68%, and provide a description of its annotation.
ESTHER : Jung_2012_J.Bacteriol_194_6665
PubMedSearch : Jung_2012_J.Bacteriol_194_6665
PubMedID: 23144409
Gene_locus related to this paper: leugj-j9ylq6

Title : Complete genome sequence of Leuconostoc carnosum strain JB16, isolated from kimchi - Jung_2012_J.Bacteriol_194_6672
Author(s) : Jung JY , Lee SH , Jeon CO
Ref : Journal of Bacteriology , 194 :6672 , 2012
Abstract : Leuconostoc carnosum strain JB16 was isolated from kimchi, the traditional Korean fermented food. Here, we report the complete genome sequence of L. carnosum strain JB16, consisting of a 1,645,096-bp circular chromosome with a G+C content of 37.24% and four plasmids.
ESTHER : Jung_2012_J.Bacteriol_194_6672
PubMedSearch : Jung_2012_J.Bacteriol_194_6672
PubMedID: 23144413
Gene_locus related to this paper: leucj-k0d810

Title : Small molecule activation of lecithin cholesterol acyltransferase modulates lipoprotein metabolism in mice and hamsters - Chen_2012_Metabolism_61_470
Author(s) : Chen Z , Wang SP , Krsmanovic ML , Castro-Perez J , Gagen K , Mendoza V , Rosa R , Shah V , He T , Stout SJ , Geoghagen NS , Lee SH , McLaren DG , Wang L , Roddy TP , Plump AS , Hubbard BK , Sinz CJ , Johns DG
Ref : Metabolism , 61 :470 , 2012
Abstract : The objective was to assess whether pharmacological activation of lecithin cholesterol acyltransferase (LCAT) could exert beneficial effects on lipoprotein metabolism. A putative small molecule activator (compound A) was used as a tool compound in in vitro and in vivo studies. Compound A increased LCAT activity in vitro in plasma from mouse, hamster, rhesus monkey, and human. To assess the acute pharmacodynamic effects of compound A, C57Bl/6 mice and hamsters received a single dose (20 mg/kg) of compound A. Both species displayed a significant increase in high-density lipoprotein cholesterol (HDLc) and a significant decrease in non-HDLc and triglycerides acutely after dosing; these changes tracked with ex vivo plasma LCAT activity. To examine compound A's chronic effect on lipoprotein metabolism, hamsters received a daily dosing of vehicle or of 20 or 60 mg/kg of compound A for 2 weeks. At study termination, compound treatment resulted in a significant increase in HDLc, HDL particle size, plasma apolipoprotein A-I level, and plasma cholesteryl ester (CE) to free cholesterol ratio, and a significant reduction in very low-density lipoprotein cholesterol. The increase in plasma CE mirrored the increase in HDL CE. Triglycerides trended toward a dose-dependent decrease in very low-density lipoprotein and HDL, with multiple triglyceride species reaching statistical significance. Gallbladder bile acids content displayed a significant and more than 2-fold increase with the 60 mg/kg treatment. We characterized pharmacological activation of LCAT by a small molecule extensively for the first time, and our findings support the potential of this approach in treating dyslipidemia and atherosclerosis; our analyses also provide mechanistic insight on LCAT's role in lipoprotein metabolism.
ESTHER : Chen_2012_Metabolism_61_470
PubMedSearch : Chen_2012_Metabolism_61_470
PubMedID: 22001333

Title : One-step identification of B and Q biotypes of Bemisia tabaci based on intron variation of carboxylesterase 2 - Kang_2012_J.Asia.Pac.Entomol_15_383
Author(s) : Kang S , Kim YH , Lee HJ , Kim BJ , Lim KJ , Lee SH
Ref : Journal of Asia-Pacific Entomology , 15 :383 , 2012
Abstract : Sequence and length-polymorphic intron variations in the caboxylesterase 2 gene (coe2) were determined to be specific to the biotypes B and Q of Bemisia tabaci. By employing the biotype-specific coe2 intron variation as a nuclear marker, a one-step diagnostic protocol for the identification of B and Q biotypes was developed and its performance was validated for field collected B. tabaci specimens. The diagnostic results based on the coe2 intron marker were identical to those obtained from the mtCOI marker in all 256 specimens examined except for four individuals that appeared to be putative heterozygotes between B and Q biotypes. These results demonstrate a high level of accuracy of the coe2 intron marker-based protocol in distinguishing biotypes B and Q. Moreover, because the process requires only PCR amplification and gel electrophoresis, analysis of multiple samples can be done more efficiently. Based on the observation that all putative heterozygotes have the maternal background of Q biotype, they may have been created by inter-biotype cross between B type male and Q type female. If combined with the mtCOI marker, the nuclear coe2 marker would provide a better resolution than maternally inherited markers alone and facilitate the demographic study of B. tabaci biotype complex.
ESTHER : Kang_2012_J.Asia.Pac.Entomol_15_383
PubMedSearch : Kang_2012_J.Asia.Pac.Entomol_15_383

Title : Monitoring of carbamate and organophosphate resistance levels in Nilaparvata lugens based on bioassay and quantitative sequencing - Kwon_2012_J.Asia.Pac.Entomol_15_635
Author(s) : Kwon DH , Min S , Lee SW , Park JH , Lee SH
Ref : Journal of Asia-Pacific Entomology , 15 :635 , 2012
Abstract : The resistance levels to carbamate (CB) and organophosphate (OP) insecticides were determined by topical application in 14 field strains of Nilaparvata lugens. The resistance levels of N. lugens to CB and OP were 1.3 ~ 47.5-fold and 1.4 ~ 14.4-fold higher than a susceptible strain, respectively. A quantitative sequencing (QS) protocol was established to determine the allele frequencies of four acetylcholinesterase point mutations putatively associated with CB and OP resistance. The allele frequencies of the four mutations (G119A, F/Y330S, F331H and I332L) in field strains ranged from ca. 0.0 ~ 51.7%, 0.0 ~ 88.9%, 5.1 ~ 56.0% and 6.7 ~ 57.3%, respectively. The F331H and I332L were tightly linked to each other, suggesting that these mutations may occur simultaneously. In correlation analysis, G119A was not well correlated with actual resistance levels (r2 = < 0.232), whereas F331H and I332L showed a better correlation with the resistance levels of benzofuranyl methylcarbamates (r2 = 0.595). This finding indicates that F331H and I332L mutation frequencies may be used as molecular markers for detecting carbamate resistance in N. lugens. A QS protocol detecting the F331H and I332L mutation frequencies could therefore be employed as a supportive tool for the rapid monitoring of CB insecticide resistance levels in N. lugens.
ESTHER : Kwon_2012_J.Asia.Pac.Entomol_15_635
PubMedSearch : Kwon_2012_J.Asia.Pac.Entomol_15_635

Title : Determination of organophosphate and carbamate resistance allele frequency in diamondback moth populations by quantitative sequencing and inhibition tests - Kim_2011_J.Asia.Pac.Entomol_14_29
Author(s) : Kim YH , Lee JH , Lee SH
Ref : Journal of Asia-Pacific Entomology , 14 :29 , 2011
Abstract : A quantitative sequencing (QS) protocol was established for predicting the frequencies of the A298S and G324A mutations in the diamondback moth (Plutella xylostella) type-1 acetylcholinesterase (AChE) locus, putatively involved in organophosphate (OP) and carbamate (CB) insecticide resistance. The nucleotide resistant signal ratio at each mutation site was generated from sequencing chromatograms and plotted against the corresponding resistance allele frequency. Frequency prediction equations were generated from the plots by linear regression, and the signal ratios were highly correlated with resistance allele frequencies (r2 > 0.987). QS analysis of 15 representative regional field populations of DBM in Korea revealed that the allele frequencies of both A298S and G324A were over 70% in most field populations, implying the prevalent state of these resistance-associated mutations. In the AChE inhibition assay, all populations showed reduced sensitivity to paraoxon, DDVP, carbaryl, and carbofuran, supporting the notion that DBM resistance to OPs and CBs is widespread in Korea.
ESTHER : Kim_2011_J.Asia.Pac.Entomol_14_29
PubMedSearch : Kim_2011_J.Asia.Pac.Entomol_14_29

Title : Establishment of an acaricide-susceptible Tetranychus urticae strain and its species confirmation based on morphological and molecular characters - Kwon_2011_J.Asia.Pac.Entomol_14_379
Author(s) : Kwon DH , Kim H , Oh JH , Lee S , Lee SH
Ref : Journal of Asia-Pacific Entomology , 14 :379 , 2011
Abstract : Acquisition of a reference Tetranychus strain that is completely susceptible to acaricides and retains an identical genetic background to acaricide-resistant strains is an essential step in elucidating mechanisms of resistance. To establish a strain completely susceptible to various acaricides, we collected Tetranychus mite populations from several regions in South Korea, including both remote and heavily cultivated regions. We tested their suitability as a susceptible reference strain by determining baseline susceptibility to six acaricides and by determining species identity as Tetranychus urticae. The UD strain, originally collected from a remote island region, was found to be most susceptible to all five major acaricides tested and was confirmed to as T. urticae on the basis of both morphological and molecular evidence. Moreover, molecular phylogenetic analysis revealed that the UD strain is an ancestral strain of other prevalently collected green-type strains. Taken together, we propose that the UD strain can be used as a susceptible reference strain for T. urticae resistance studies as it provides baseline susceptibility to acaricides and possesses a common genetic background with most other acaricide-resistant strains.
ESTHER : Kwon_2011_J.Asia.Pac.Entomol_14_379
PubMedSearch : Kwon_2011_J.Asia.Pac.Entomol_14_379

Title : Three acetylcholinesterases of the pinewood nematode, Bursaphelenchus xylophilus: insights into distinct physiological functions - Kang_2011_Mol.Biochem.Parasitol_175_154
Author(s) : Kang JS , Lee DW , Choi JY , Je YH , Koh YH , Lee SH
Ref : Molecular & Biochemical Parasitology , 175 :154 , 2011
Abstract : Acetylcholinesterase (AChE) plays a key role in postsynaptic transmission in most animals. Nematodes encode multiple AChEs, implying its functional diversity. To explore physiological functions of multiple AChEs, three distinct AChEs (BxACE-1, BxACE-2, and BxACE-3) were identified and characterized from the pinewood nematode. Sequencing comparison with Torpedo AChE and Caenorhabditis elegans ACEs identified choline-binding site, catalytic triad functional site, three internal disulfide bonds and aromatic residues for the catalytic gorge. Transcriptional profiling by quantitative real-time PCR revealed that BxACE-3 is more actively transcribed than BxACE-1 (2-3 times) and BxACE-2 (9-18 times) in both propagative and dispersal stages. The three BxACEs were functionally expressed using baculovirus system. Kinetic analysis of in vitro-expressed BxACEs revealed that the substrate specificity was highest in BxACE-1 whereas the catalytic efficiency was highest in BxACE-2. In inhibition assay, BxACE-3 showed the lowest inhibition rate. Taken together, it appears that both BxACE-1 and BxACE-2 play common but non-overlapping roles in synaptic transmission, whereas BxACE-3 may have non-neuronal functions. The current findings should provide valuable insights into the evolutionary process and various physiological roles of AChE.
ESTHER : Kang_2011_Mol.Biochem.Parasitol_175_154
PubMedSearch : Kang_2011_Mol.Biochem.Parasitol_175_154
PubMedID: 21074580
Gene_locus related to this paper: burxy-ACHE1 , burxy-ACHE2 , burxy-ACHE3

Title : A soluble acetylcholinesterase provides chemical defense against xenobiotics in the pinewood nematode - Kang_2011_PLoS.One_6_e19063
Author(s) : Kang JS , Lee DW , Koh YH , Lee SH
Ref : PLoS ONE , 6 :e19063 , 2011
Abstract : The pinewood nematode genome encodes at least three distinct acetylcholinesterases (AChEs). To understand physiological roles of the three pinewood nematode AChEs (BxACE-1, BxACE-2, and BxACE-3), BxACE-3 in particular, their tissue distribution and inhibition profiles were investigated. Immunohistochemistry revealed that BxACE-1 and BxACE-2 were distributed in neuronal tissues. In contrast, BxACE-3 was detected from some specific tissues and extracted without the aid of detergent, suggesting its soluble nature unlike BxACE-1 and BxACE-2. When present together, BxAChE3 significantly reduced the inhibition of BxACE-1 and BxACE-2 by cholinesterase inhibitors. Knockdown of BxACE-3 by RNA interference significantly increased the toxicity of three nematicidal compounds, supporting the protective role of BxACE-3 against chemicals. In summary, BxACE-3 appears to have a non-neuronal function of chemical defense whereas both BxACE-1 and BxACE-2 have classical neuronal function of synaptic transmission.
ESTHER : Kang_2011_PLoS.One_6_e19063
PubMedSearch : Kang_2011_PLoS.One_6_e19063
PubMedID: 21556353
Gene_locus related to this paper: burxy-ACHE3

Title : Pharmacogenetic Regulation of Acetylcholinesterase Activity in Drosophila Reveals the Regulatory Mechanisms of AChE Inhibitors in Synaptic Plasticity - Kim_2011_Neurochem.Res_36_879
Author(s) : Kim W , Lee D , Choi J , Kim A , Han S , Park K , Kim J , Choi Y , Lee SH , Koh YH
Ref : Neurochem Res , 36 :879 , 2011
Abstract : We conducted experiments in Drosophila to investigate the consequences of altered acetylcholinesterase (AChE) activity in the nervous system. In ace hypomorphic mutant larvae, the amount of ace mRNA and the activity of AChE both in vivo and in vitro were significantly reduced compared with those of controls. Reduced Ace in Drosophila larvae resulted in significant down-regulation of branch length and the number of boutons in Type 1 glutamatergic neuromuscular junctions (NMJs). These defects in ace hypomorphic mutant larvae were suppressed when Musca domestica AChE was transgenically expressed. Because AChE inhibitors are utilized for medications for Alzheimer's disease, we investigated whether pharmacological inhibition of AChE activity induced any synaptic defects. We found that controls exposed to a sublethal dose of DDVP phenocopied the synaptic structural defects of the ace hypomorphic mutant. These results suggest that down-regulation of AChE activity, regardless of whether it is due to genetic or pharmacological manipulations, results in altered synaptic architecture. Our study suggests that exposure to AChE inhibitors for 6-12 months may induce altered synaptic architectures in human brains with Alzheimer's diseases, similar to those reported here. These changes may underlie or contribute to the loss of efficacy of AChE inhibitors after prolonged treatment.
ESTHER : Kim_2011_Neurochem.Res_36_879
PubMedSearch : Kim_2011_Neurochem.Res_36_879
PubMedID: 21305389

Title : Novel metagenome-derived carboxylesterase that hydrolyzes beta-lactam antibiotics - Jeon_2011_Appl.Environ.Microbiol_77_7830
Author(s) : Jeon JH , Kim SJ , Lee HS , Cha SS , Lee JH , Yoon SH , Koo BS , Lee CM , Choi SH , Lee SH , Kang SG
Ref : Applied Environmental Microbiology , 77 :7830 , 2011
Abstract : It has been proposed that family VIII carboxylesterases and class C beta-lactamases are phylogenetically related; however, none of carboxylesterases has been reported to hydrolyze beta-lactam antibiotics except nitrocefin, a nonclinical chromogenic substrate. Here, we describe the first example of a novel carboxylesterase derived from a metagenome that is able to cleave the amide bond of various beta-lactam substrates and the ester bond of p-nitrophenyl esters. A clone with lipolytic activity was selected by functional screening of a metagenomic library using tributyrin agar plates. The sequence analysis of the clone revealed the presence of an open reading frame (estU1) encoding a polypeptide of 426 amino acids, retaining an S-X-X-K motif that is conserved in class C beta-lactamases and family VIII carboxylesterases. The gene was overexpressed in Escherichia coli, and the purified recombinant protein (EstU1) was further characterized. EstU1 showed esterase activity toward various chromogenic p-nitrophenyl esters. In addition, it exhibited hydrolytic activity toward nitrocefin, leading us to investigate whether EstU1 could hydrolyze beta-lactam antibiotics. EstU1 was able to hydrolyze first-generation beta-lactam antibiotics, such as cephalosporins, cephaloridine, cephalothin, and cefazolin. In a kinetic study, EstU1 showed a similar range of substrate affinities for both p-nitrophenyl butyrate and first-generation cephalosporins while the turnover efficiency for the latter was much lower. Furthermore, site-directed mutagenesis studies revealed that the catalytic triad of EstU1 plays a crucial role in hydrolyzing both ester bonds of p-nitrophenyl esters and amide bonds of the beta-lactam ring of antibiotics, implicating the predicted catalytic triad of EstU1 in both activities.
ESTHER : Jeon_2011_Appl.Environ.Microbiol_77_7830
PubMedSearch : Jeon_2011_Appl.Environ.Microbiol_77_7830
PubMedID: 21908637

Title : Complete genome sequence of Leuconostoc kimchii strain C2, isolated from Kimchi - Lee_2011_J.Bacteriol_193_5548
Author(s) : Lee SH , Jung JY , Jeon CO
Ref : Journal of Bacteriology , 193 :5548 , 2011
Abstract : Leuconostoc kimchii strain C2 was isolated from fermented kimchi in Korea. Here we announce the complete genome sequence of Leuconostoc kimchii strain C2, consisting of a 1,877,174-bp chromosome with a G+C content of 37.9% and no plasmid and describe major findings from its annotation.
ESTHER : Lee_2011_J.Bacteriol_193_5548
PubMedSearch : Lee_2011_J.Bacteriol_193_5548
PubMedID: 21914872
Gene_locus related to this paper: leuki-d5t0e2

Title : Production of medium-chain-length polyhydroxyalkanoates by activated sludge enriched under periodic feeding with nonanoic acid - Lee_2011_Bioresour.Technol_102_6159
Author(s) : Lee SH , Kim JH , Mishra D , Ni YY , Rhee YH
Ref : Bioresour Technol , 102 :6159 , 2011
Abstract : The potential use of activated sludge for the production of medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was investigated. The enrichment of bacterial populations capable of producing MCL-PHAs was achieved by periodic feeding with nonanoic acid in a sequencing batch reactor (SBR). Denaturing gradient gel electrophoresis analysis revealed Pseudomonas aeruginosa strains to be predominant in the bacterial community during the SBR process. The composition of PHA synthesized by the enriched biomass from nonanoic acid consisted of a large concentration (>89 mol%) of MCL monomer units and a small amount of short-chain-length monomer units. Under fed-batch fermentation with continuous feeding of nonanoic acid at a flow rate of 0.225 g/L/h and a C/N ratio of 40, a maximum PHA content of 48.6% dry cell weight and a conversion yield (Y(p/s)) of 0.94 g/g were achieved. These results indicate that MCL-PHA production by activated sludge is a promising alternative to typical pure culture approaches.
ESTHER : Lee_2011_Bioresour.Technol_102_6159
PubMedSearch : Lee_2011_Bioresour.Technol_102_6159
PubMedID: 21463934

Title : Complete genome sequence of Weissella koreensis KACC 15510, isolated from kimchi - Lee_2011_J.Bacteriol_193_5534
Author(s) : Lee SH , Jung JY , Jeon CO
Ref : Journal of Bacteriology , 193 :5534 , 2011
Abstract : Weissella koreensis KACC 15510 was isolated from kimchi, a representative traditional Korean fermented food. Here, we announce the complete genome sequence of W. koreensis KACC 15510, consisting of a 1,422,478-bp chromosome and one 18,992-bp plasmid, and provide a description of their annotation.
ESTHER : Lee_2011_J.Bacteriol_193_5534
PubMedSearch : Lee_2011_J.Bacteriol_193_5534
PubMedID: 21914863
Gene_locus related to this paper: weikk-f8hxu1 , weikk-f8hzi9

Title : Development of a low-density DNA microarray for diagnosis of target-site mutations of pyrethroid and organophosphate resistance mutations in the whitefly Bemisia tabaci - Chung_2011_Pest.Manag.Sci_67_1541
Author(s) : Chung IH , Kang S , Kim YR , Kim JH , Jung JW , Lee S , Lee SH , Hwang SY
Ref : Pest Manag Sci , 67 :1541 , 2011
Abstract : BACKGROUND: Rapid and accurate detection of mutations related to insecticide resistance is essential for development of resistance management strategies to support sustainable agriculture. The M918V, L925I and T929V mutations of the voltage-gated sodium channel gene (vgsc) and the F392W mutation of the acetylcholinesterase I gene (ace1) are reportedly associated with resistance to pyrethroids and organophosphates, respectively, in Bemisia tabaci. In order to detect known base substitutions in the ace1 and vgsc genes, a low-density microarray with an allele-specific probe was developed. RESULTS: Specific regions of the ace1 and vgsc gene mutations were amplified by multiplex asymmetrical PCR using Cy3-labelled primers, and then the PCR products were hybridised on the microarray. After analysing the probe signal data, the microarray containing 12 allele-specific probes produced a unique pattern of probe signals for field DNA samples of B. tabaci. To determine the optimal cut-off value of each probe, receiver operating characteristic (ROC) curve analysis was conducted using SPSS. Among 60 individual samples, microarray data for 57 samples were consistent with direct sequencing data. CONCLUSION: Although many molecular detection methods have been employed to monitor insecticide resistance, the present microarray provides rapid and accurate identification of target mutations in B. tabaci for resistance management.
ESTHER : Chung_2011_Pest.Manag.Sci_67_1541
PubMedSearch : Chung_2011_Pest.Manag.Sci_67_1541
PubMedID: 21710552

Title : Acetylcholinesterase point mutations putatively associated with monocrotophos resistance in the two-spotted spider mite - Kwon_2010_Pestic.Biochem.Physiol_96_36
Author(s) : Kwon DH , Im JS , Ahn JJ , Lee J-H , Clark JM , Lee SH
Ref : Pesticide Biochemistry and Physiology , 96 :36 , 2010
Abstract : Molecular mechanisms of monocrotophos resistance in the two-spotted spider mite (TSSM), Tetranychus urticae Koch, were investigated. A monocrotophos-resistant strain (AD) showed ca. 3568- and 47.6-fold resistance compared to a susceptible strain (UD) and a moderately resistant strain (PyriF), respectively. No significant differences in detoxification enzyme activities, except for the cytochrome P450 monooxygenase activity, were found among the three strains. The sensitivity of acetylcholinesterase (AChE) to monocrotophos, however, was 90.6- and 41.9-fold less in AD strain compared to the UD and PyriF strains, respectively, indicating that AChE insensitivity mechanism plays a major role in monocrotophos resistance. When AChE gene (Tuace) sequences were compared, three point mutations (G228S, A391T and F439W) were identified in Tuace from the AD strain that likely contribute to the AChE insensitivity as predicted by structure analysis. Frequencies of the three mutations in field populations were predicted by quantitative sequencing (QS). Correlation analysis between the mutation frequency and actual resistance levels (LC50) of nine field populations suggested that the G228S mutation plays a more crucial role in resistance (r2 = 0.712) compared to the F439W mutation (r2 = 0.419). When correlated together, however, the correlation coefficient was substantially enhanced (r2 = 0.865), indicating that both the F439W and G228S mutations may work synergistically. The A391T mutation was homogeneously present in all field populations examined, suggesting that it may confer a basal level of resistance.
ESTHER : Kwon_2010_Pestic.Biochem.Physiol_96_36
PubMedSearch : Kwon_2010_Pestic.Biochem.Physiol_96_36
Gene_locus related to this paper: tetur-ACHE

Title : Extensive gene duplication of acetylcholinesterase associated with organophosphate resistance in the two-spotted spider mite - Kwon_2010_Insect.Mol.Biol_19_195
Author(s) : Kwon DH , Clark JM , Lee SH
Ref : Insect Molecular Biology , 19 :195 , 2010
Abstract : Monocrotophos-resistant two-spotted spider mites (TSSMs), Tetranychus urticae, are known to possess three mutations on the acetylcholinesterase (AChE) gene (Tuace) that are involved in target site insensitivity. Cross-strain comparison of three strains (highly resistant AD, moderately resistant PyriF and susceptible UD strains) revealed that resistant strains have relatively more Tuace copies than the UD strain and that the levels of transcript were directly proportional to copy numbers. AChEs from the AD and PyriF strains had similar V(max) values to those of AChE from the UD strain but increased K(m) and reduced k(cat) constants, suggesting that the mutated, resistant form of AChE may carry a fitness cost. Relative copy numbers of Tuace in field populations varied from 2.4 to 6.1, correlating well with their levels of resistance (r(2)= 0.895). These results are suggestive of the involvement of Tuace gene duplication in resistance. Thus, monocrotophos resistance in TSSMs appears to have evolved through a combination of mutation accumulation and extensive gene duplication.
ESTHER : Kwon_2010_Insect.Mol.Biol_19_195
PubMedSearch : Kwon_2010_Insect.Mol.Biol_19_195
PubMedID: 20002213
Gene_locus related to this paper: tetur-ACHE

Title : Functional analysis and molecular characterization of two acetylcholinesterases from the German cockroach, Blattella germanica - Kim_2010_Insect.Mol.Biol_19_765
Author(s) : Kim YH , Choi JY , Je YH , Koh YH , Lee SH
Ref : Insect Molecular Biology , 19 :765 , 2010
Abstract : Two acetylcholinesterases (AChEs; BgAChE1 and BgAChE2) from Blattella germanica were functionally expressed using the baculovirus system. Kinetic analysis demonstrated that BgAChE2 had higher catalytic efficiency but lower substrate specificity than BgAChE1. With the exceptions of paraoxon and propoxur, BgAChE1 was generally less sensitive to inhibitors than BgAChE2. Western blot analysis using anti-BgAChE antibodies revealed that BgAChE1 was far more abundant in all examined tissues compared to BgAChE2, which is only present in the central nervous system. Both BgAChEs existed in dimeric form, covalently connected via a disulphide bridge under native conditions. Most fractions of BgAChE1 had a glycophosphatidylinositol (GPI) anchor, but a small fraction comprised a collagen-like tail. BgAChE2 appeared to have a collagen-GPI-fused tail. Based on the kinetic and molecular properties, tissue distribution and abundance, BgAChE1 was confirmed to play a major role in postsynaptic transmission.
ESTHER : Kim_2010_Insect.Mol.Biol_19_765
PubMedSearch : Kim_2010_Insect.Mol.Biol_19_765
PubMedID: 20738424
Gene_locus related to this paper: blage-ACHE1 , blage-ACHE2

Title : Enhanced display of lipase on the Escherichia coli cell surface, based on transcriptome analysis - Baek_2010_Appl.Environ.Microbiol_76_971
Author(s) : Baek JH , Han MJ , Lee SH , Lee SY
Ref : Applied Environmental Microbiology , 76 :971 , 2010
Abstract : A cell surface display system was developed using Escherichia coli OmpC as an anchoring motif. The fused Pseudomonas fluorescens SIK W1 lipase was successfully displayed on the surface of E. coli cells, and the lipase activity could be enhanced by the coexpression of the gadBC genes identified by transcriptome analysis.
ESTHER : Baek_2010_Appl.Environ.Microbiol_76_971
PubMedSearch : Baek_2010_Appl.Environ.Microbiol_76_971
PubMedID: 19948866

Title : Optimization of lipase-catalyzed glucose ester synthesis in ionic liquids - Ha_2010_Bioprocess.Biosyst.Eng_33_63
Author(s) : Ha SH , Hiep NM , Lee SH , Koo YM
Ref : Bioprocess Biosyst Eng , 33 :63 , 2010
Abstract : Lipase-catalyzed esterification of glucose with fatty acids in ionic liquids (ILs) mixture was investigated by using supersaturated glucose solution. The effect of ILs mixture ratio, substrate ratio, lipase content, and temperature on the activity and stability of lipase was also studied. The highest yield of sugar ester was obtained in a mixture of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][TfO]) and 1-methyl-3-octylimidazolium bis[(trifluoromethyl)-sulfonyl]amide ([Omim][Tf(2)N]) with a volume ratio of 9:1, while Novozym 435 (Candida antarctica type B lipase immobilized on acrylic resin) showed the optimal stability and activity in a mixture of [Bmim][TfO] and [Omim][Tf(2)N] with a 1:1 volume ratio. Reuse of lipase and ILs was successfully carried out at the optimized reaction conditions. After 5 times reuse of Novozym 435 and ILs, 78% of initial activity was remained.
ESTHER : Ha_2010_Bioprocess.Biosyst.Eng_33_63
PubMedSearch : Ha_2010_Bioprocess.Biosyst.Eng_33_63
PubMedID: 19680693

Title : Cloning of a sodium channel gene and identification of mutations putatively associated with fenpropathrin resistance in Tetranychus urticae - Kwon_2010_Pestic.Biochem.Physiol_97_93
Author(s) : Kwon DH , Clark JM , Lee SH
Ref : Pesticide Biochemistry and Physiology , 97 :93 , 2010
Abstract : Tetranychus urticae Koch is the most serious mite pest to various orchard trees and garden plants. Biochemical and molecular analyses were conducted to elucidate resistance mechanisms in a fenpropathrin-resistant mite strain (FenR). No significant differences were found in the activities of carboxylesterase and glutathione-S-transferase between the susceptible (UD and PyriF) and FenR strains. Cytchrome P450 activity was highest in PyriF, followed by FenR and UD. Analysis of detoxification enzyme assays, therefore, suggested that metabolic detoxification plays little role, if any, in fenpropathrin resistance. However, the FenR strain showed approximately 104- and 33.3-fold slower knockdown responses than UD and PyriF strains, respectively, suggestive of sodium channel insensitivity as a major resistance mechanism. We cloned cDNA fragments of the para-homologous sodium channel [alpha]-subunit gene (Tuvssc) and determined its full-length nucleotide sequences. The complete open reading frame of Tuvssc was 6627 nucleotides, encoding 2209 amino acids. The amino acid sequences of Tuvssc were 47.5% and 51.2% identical to the fruit fly and varroa mite, respectively. Amino acid sequence comparison between the three strains revealed two mutations (L1022V and A1376D) and one deletion (HisDel1278-1280) found only in FenR mites, among which the L1022V mutation was proposed to play a major role in knockdown resistance to fenpropathrin.
ESTHER : Kwon_2010_Pestic.Biochem.Physiol_97_93
PubMedSearch : Kwon_2010_Pestic.Biochem.Physiol_97_93

Title : Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle - Kirkness_2010_Proc.Natl.Acad.Sci.U.S.A_107_12168
Author(s) : Kirkness EF , Haas BJ , Sun W , Braig HR , Perotti MA , Clark JM , Lee SH , Robertson HM , Kennedy RC , Elhaik E , Gerlach D , Kriventseva EV , Elsik CG , Graur D , Hill CA , Veenstra JA , Walenz B , Tubio JM , Ribeiro JM , Rozas J , Johnston JS , Reese JT , Popadic A , Tojo M , Raoult D , Reed DL , Tomoyasu Y , Kraus E , Mittapalli O , Margam VM , Li HM , Meyer JM , Johnson RM , Romero-Severson J , Vanzee JP , Alvarez-Ponce D , Vieira FG , Aguade M , Guirao-Rico S , Anzola JM , Yoon KS , Strycharz JP , Unger MF , Christley S , Lobo NF , Seufferheld MJ , Wang N , Dasch GA , Struchiner CJ , Madey G , Hannick LI , Bidwell S , Joardar V , Caler E , Shao R , Barker SC , Cameron S , Bruggner RV , Regier A , Johnson J , Viswanathan L , Utterback TR , Sutton GG , Lawson D , Waterhouse RM , Venter JC , Strausberg RL , Berenbaum MR , Collins FH , Zdobnov EM , Pittendrigh BR
Ref : Proc Natl Acad Sci U S A , 107 :12168 , 2010
Abstract : As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.
ESTHER : Kirkness_2010_Proc.Natl.Acad.Sci.U.S.A_107_12168
PubMedSearch : Kirkness_2010_Proc.Natl.Acad.Sci.U.S.A_107_12168
PubMedID: 20566863
Gene_locus related to this paper: pedhb-ACHE1 , pedhb-ACHE2 , pedhc-e0v9b5 , pedhc-e0v9b6 , pedhc-e0v9b7 , pedhc-e0vbv5 , pedhc-e0vcd0 , pedhc-e0vcl7 , pedhc-e0vd69 , pedhc-e0ve50 , pedhc-e0vel6 , pedhc-e0vel7 , pedhc-e0vf98 , pedhc-e0vfs8 , pedhc-e0vfv0 , pedhc-e0vg01 , pedhc-e0vha2 , pedhc-e0vha4 , pedhc-e0vi52 , pedhc-e0vp42 , pedhc-e0vqu6 , pedhc-e0vuj9 , pedhc-e0vup6 , pedhc-e0vv55 , pedhc-e0vwv3 , pedhc-e0vxf7 , pedhc-e0vxg1 , pedhc-e0w4a6 , pedhc-e0w4c8 , pedhc-e0w271 , pedhc-e0w444 , pedhc-e0vym0 , pedhc-e0vdk9 , pedhc-e0vk10 , pedhc-e0vgw4 , pedhc-e0vgw7 , pedhc-e0vga1 , pedhc-e0w3s1 , pedhc-e0vzt2

Title : Alterations in both acetylcholinesterase activity and synaptic scaffolding protein localization in the nervous system of Drosophila presenilin mutants - Kim_2010_J.Asia.Pac.Entomol_13_339
Author(s) : Kim WT , Choi HJ , Park Y , Kim AY , Kim YH , Seo J , Lee SH , Koh YH
Ref : Journal of Asia-Pacific Entomology , 13 :339 , 2010
Abstract : Presenilins are one of two types of critical genetic factors in familial Alzheimer's disease, and they regulate various cellular functions such as intracellular Ca2+ homeostasis, the endoplasmic reticulum (ER) stress response, apoptosis, and synaptic transmission. We utilized Drosophila presenilin (psn) mutants as a model for studying the role of this gene in regulating acetylcholinesterase activity (AChE) and synaptic plasticity. Several lines of biochemical evidence indicated that AChE activity in a functionally null psn mutant (psnB3) was significantly reduced. In addition, we also found that psnB3 mutant neuromuscular junctions (NMJs) had smaller synaptic boutons and altered localization of Discs large, a synaptic scaffolding protein at the synaptic terminals compared to wild-type controls. These phenotypic defects were completely rescued in transgenic lines expressing the long form of wild-type Psn under an endogenous psn promoter cassette (PEPC-PsnWT;psnB3 lines). Taken together, these results indicate that Psn is important for regulating AChE activity, the size of synaptic boutons, and the localization of DLG at synaptic terminals.
ESTHER : Kim_2010_J.Asia.Pac.Entomol_13_339
PubMedSearch : Kim_2010_J.Asia.Pac.Entomol_13_339

Title : Characterization of carboxylesterase-mediated pirimicarb resistance in Myzus persicae - Kwon_2009_Pestic.Biochem.Physiol_93_120
Author(s) : Kwon DH , Choi BR , Lee SW , Clark JM , Lee SH
Ref : Pesticide Biochemistry and Physiology , 93 :120 , 2009
Abstract : The biochemical and molecular mechanisms of pirimicarb resistance were investigated in a pirimicarb-resistant (Pc-R) strain of Myzus persicae. The Pc-R strain showed a 131-fold resistance to pirimicarb but no or slight cross-resistance to other organophosphate and carbamate insecticides. Interestingly, the strain showed a moderate level of cross-resistance to neonicotinoids. Sequence analysis of the acetylcholinesterase (AChE) gene revealed that the Ser431Phe mutation, previously known to be associated with AChE insensitivity, was saturated in the Pc-R strain, and the AChE insensitivity caused by the mutation is likely a major pirimicarb resistance mechanism. In addition, detoxifying enzyme assays suggested that enhanced carboxylesterase (CbE) activity is associated with pirimicarb resistance as a supporting mechanism. The higher CbE activity in the Pc-R strain was determined to be mainly due to a pI 4.9 esterase by native isoelectricfocusing. The resistance-associated CbE was further identified as the E4 type by native two-dimensional gel electrophoresis in conjunction with matrix-assisted laser desorption ionization-time of flight mass spectrometry. The gene copy number and transcription level of the E4 CbE were increased 4.0- and 10.5-fold in the Pc-R strain, respectively, suggesting that both gene duplication and transcriptional regulation of E4 CbE are associated with pirimicarb resistance.
ESTHER : Kwon_2009_Pestic.Biochem.Physiol_93_120
PubMedSearch : Kwon_2009_Pestic.Biochem.Physiol_93_120

Title : Identification of a serotonin receptor coupled to adenylyl cyclase involved in learning-related heterosynaptic facilitation in Aplysia - Lee_2009_Proc.Natl.Acad.Sci.U.S.A_106_14634
Author(s) : Lee YS , Choi SL , Lee SH , Kim H , Park H , Lee N , Chae YS , Jang DJ , Kandel ER , Kaang BK
Ref : Proc Natl Acad Sci U S A , 106 :14634 , 2009
Abstract : Serotonin (5-HT) plays a critical role in modulating synaptic plasticity in the marine mollusc Aplysia and in the mammalian nervous system. In Aplysia sensory neurons, 5-HT can activate several signal cascades, including PKA and PKC, presumably via distinct types of G protein-coupled receptors. However, the molecular identities of these receptors have not yet been identified. We here report the cloning and functional characterization of a 5-HT receptor that is positively coupled to adenylyl cyclase in Aplysia neurons. The cloned receptor, 5-HT(apAC1), stimulates the production of cAMP in HEK293T cells and in Xenopus oocytes. Moreover, the knockdown of 5-HT(apAC1) expression by RNA interference blocked 5-HT-induced cAMP production in Aplysia sensory neurons and blocked synaptic facilitation in nondepressed or partially depressed sensory-to-motor neuron synapses. These data implicate 5-HT(apAC1) as a major modulator of learning related synaptic facilitation in the direct sensory to motor neuron pathway of the gill withdrawal reflex.
ESTHER : Lee_2009_Proc.Natl.Acad.Sci.U.S.A_106_14634
PubMedSearch : Lee_2009_Proc.Natl.Acad.Sci.U.S.A_106_14634
PubMedID: 19706550

Title : Chitooligosaccharides suppress the level of protein expression and acetylcholinesterase activity induced by Abeta25-35 in PC12 cells - Lee_2009_Bioorg.Med.Chem.Lett_19_860
Author(s) : Lee SH , Park JS , Kim SK , Ahn CB , Je JY
Ref : Bioorganic & Medicinal Chemistry Lett , 19 :860 , 2009
Abstract : Clinical applications of acetylcholinesterase (AChE) inhibitors are widespread in Alzheimer's sufferers in order to activate central cholinergic system and alleviate cognitive deficits by inhibiting the hydrolysis of acetylcholine. In this study, six kinds of chitooligosaccharides (COSs) with different molecular weight and degree of deacetylation were examined for their inhibitory effects against AChE. The 90-COSs exhibited potent AChE inhibitory activities compared to 50-COSs, while 90-MMWCOS (1000-5000 Da) in the 90-COSs showed the highest activity. Cell culture experiment revealed that 90-MMWCOS suppressed the level of AChE protein expression and AChE activity induced by Abeta(25-35) in PC12 cell lines.
ESTHER : Lee_2009_Bioorg.Med.Chem.Lett_19_860
PubMedSearch : Lee_2009_Bioorg.Med.Chem.Lett_19_860
PubMedID: 19097785

Title : BT-11 improves stress-induced memory impairments through increment of glucose utilization and total neural cell adhesion molecule levels in rat brains - Shin_2009_J.Neurosci.Res_87_260
Author(s) : Shin KY , Won BY , Heo C , Kim HJ , Jang DP , Park CH , Kim S , Kim HS , Kim YB , Lee HG , Lee SH , Cho ZH , Suh YH
Ref : Journal of Neuroscience Research , 87 :260 , 2009
Abstract : In Oriental medicine, roots of Polygala tenuifolia Willdenow have been known to be an important herb that exhibits sedative effects in insomnia, palpitation with anxiety, restlessness, and disorientation in humans. We previously reported that BT-11, extracted from those roots, improved scopolamine-induced amnesia in rats and inhibited acetylcholinesterase activities in vitro. Therefore, we proposed that BT-11 could remedy stress-induced memory deficits in rats. In this study, the stress-induced memory impairments in rats were significantly reversed almost to the control level by BT-11 treatment. To seek an active component of BT-11 that plays an important role in antipsychotic effects, we compared BT-11 with 3,4,5-trimethoxycinnamic acid (TMCA), which is a constituent of those root extracts. However, the effects of TMCA were less or were not consistent with those of BT-11 in some of tests. In particular, BT-11 reversed the stress-induced reduction of glucose utilization by [(18)fluorodeoxyglucose]FDG-PET and the levels of neural cell adhesion molecule (NCAM) in rat brains to the control levels, whereas TMCA did not. Therefore, BT-11 improved stress-induced memory impairments through increment of glucose utilization and total NCAM levels in rat brains. In conclusion, BT-11 may be strongly effective against stress-induced amnesia in rats, through the combined effects of TMCA and other active components of BT-11.
ESTHER : Shin_2009_J.Neurosci.Res_87_260
PubMedSearch : Shin_2009_J.Neurosci.Res_87_260
PubMedID: 18712849

Title : Pharmacokinetics and pharmacodynamics of LC15-0444, a novel dipeptidyl peptidase IV inhibitor, after multiple dosing in healthy volunteers - Lim_2009_Br.J.Clin.Pharmacol_68_883
Author(s) : Lim KS , Cho JY , Kim BH , Kim JR , Kim HS , Kim DK , Kim SH , Yim HJ , Lee SH , Shin SG , Jang IJ , Yu KS
Ref : British Journal of Clinical Pharmacology , 68 :883 , 2009
Abstract : WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * The importance of efficient drug development using biomarkers has been increasingly emphasized, from preclinical studies to clinical trials. * However, as yet few validated or qualified biomarkers are used in early-stage drug development in terms of clinical pharmacology and disease pathophysiology. WHAT THIS STUDY ADDS: * This first-time-in-human study provides evidence of the pharmacological activity of LC15-0444 in humans, by using dipeptidyl peptidase IV activity and active glucagon-like peptide-1 concentrations. * LC15-0444 possesses pharmacokinetic and pharmacodynamic characteristics that support a once-daily dosing regimen. AIMS: LC15-0444 is a selective and competitive inhibitor of dipeptidyl peptidase (DPP) IV with potential for the treatment of Type 2 diabetes. The aim was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD) profiles after multiple oral ascending doses of LC15-0444 in healthy male subjects. METHODS: A dose block-randomized, double-blind, placebo-controlled, parallel group study was performed in three groups with 10 subjects (eight for active drug; two for placebo) per group; each group received 200, 400 or 600 mg of LC15-0444 once daily for 10 days. Blood and urine samples were collected up to 24 h after the first dosing and up to 72 h after the last dosing. RESULTS: The LC15-0444 concentration-time profiles exhibited characteristics of multicompartment disposition. No dose- or time-dependent change in PK parameters was observed. Mean elimination half-life was in a range 16.6-20.1 h in the dose groups. Mean renal clearance and fraction of unchanged drug excreted in urine was 18.6-21.9 and 0.40-0.48 l h(-1), respectively. In the steady state, mean accumulation ratios by dose groups were between 1.22 and 1.31. More than 80% inhibition of DPP IV activity from baseline was sustained for >24 h in all dose groups. CONCLUSIONS: This study provides evidence of the pharmacological activity of LC15-0444 in humans. LC15-0444 possesses PK and PD characteristics that support a once-daily dosing regimen.
ESTHER : Lim_2009_Br.J.Clin.Pharmacol_68_883
PubMedSearch : Lim_2009_Br.J.Clin.Pharmacol_68_883
PubMedID: 20002082

Title : Genetic variations in soluble epoxide hydrolase and graft function in kidney transplantation - Lee_2008_Transplant.Proc_40_1353
Author(s) : Lee SH , Lee J , Cha R , Park MH , Ha JW , Kim S , Kim YS
Ref : Transplant Proc , 40 :1353 , 2008
Abstract : BACKGROUND: Epoxyeicosatrienoic acids (EETs) are endothelium-derived hyperpolarizing factors that contribute renal protective actions. The aim of this study was to identify the association between genetic variations in soluble epoxide hydrolase (EPHX2, EET-metabolizing enzyme) and kidney allograft dysfunction.
MATERIALS AND METHODS: Data from 204 kidney transplant donor-recipient pairs were examined for polymorphisms of exon 8 (R287Q, rs751141 G/A) and 3' untranslated region (3' UTR, rs1042032 A/G) of the EPHX2 gene and correlated with clinical data.
RESULTS: The mean duration of follow-up for recipients was 58 +/- 45.3 months who were 39 +/- 11.8 years old at the time of operation and displayed estimated glomerular filtration rate (eGFR) of 68 +/- 16.5 mL/min/1.73 m2 at 1 month after transplantation. AA, AG, and GG genotype frequencies in 3' UTR were 28%, 55%, and 16%, respectively. Twenty-one recipients experienced allograft dysfunction with eGFR <30 mL/min/1.73 m2; 10 had AA genotype of rs1042032 polymorphism (chi-square test; A/A vs A/G+G/G; P = .04). Recipients without rs1042032 polymorphism variant allele showed a significant risk for allograft dysfunction (A/A vs A/G+G/G; P = .04; odds ratio, 2.65; 95% confidence interval [CI], 1.03-6.81). Multivariate analysis of the characteristics of patients using a Cox proportional hazard model showed that the AA genotype of rs1042032 polymorphism was predictive of allograft dysfunction (Hazard Ratio = 3.26; P = .04; 95% CI, 1.08-9.59). CONCLUSION: The present study suggested that the presence of the rs1042032 variant allele in EPHX2 was associated with a protective role for allograft function.
ESTHER : Lee_2008_Transplant.Proc_40_1353
PubMedSearch : Lee_2008_Transplant.Proc_40_1353
PubMedID: 18589104

Title : Lipase-catalyzed synthesis of glucose fatty acid ester using ionic liquids mixtures - Lee_2008_J.Biotechnol_133_486
Author(s) : Lee SH , Ha SH , Hiep NM , Chang WJ , Koo YM
Ref : J Biotechnol , 133 :486 , 2008
Abstract : Novozym 435-catalyzed synthesis of 6-O-lauroyl-d-glucose in ionic liquids (ILs) was investigated. The highest lipase activity was obtained in water-miscible [Bmim][TfO] which can dissolve high concentration of glucose, while the highest stability of lipase was shown in hydrophobic [Bmim][Tf(2)N]. The optimal activity and stability of lipase could be obtained in [Bmim][TfO] and [Bmim][Tf(2)N] mixture (1:1, v/v). Specifically, the activity of lipase was increased from 1.1 to 2.9 micromolmin(-1)g(-1) by using supersaturated glucose solution in this mixture, compared with reaction using saturated solution. After 5 times reuse of lipase, 86% of initial activity was remained in this mixture, while the residual activity in pure [Bmim][TfO] was 36%. Therefore, the productivity obtained by using ILs mixtures was higher than those in pure ILs.
ESTHER : Lee_2008_J.Biotechnol_133_486
PubMedSearch : Lee_2008_J.Biotechnol_133_486
PubMedID: 18160167

Title : High-resolution structure of ybfF from Escherichia coli K12: a unique substrate-binding crevice generated by domain arrangement. - Park_2008_J.Mol.Biol_376_1426
Author(s) : Park SY , Lee SH , Lee J , Nishi K , Kim YS , Jung CH , Kim JS
Ref : Journal of Molecular Biology , 376 :1426 , 2008
Abstract : Esterases are one of the most common enzymes and are involved in diverse cellular functions. ybfF protein from Escherichia coli (Ec_ybfF) belongs to the esterase family for the large substrates, palmitoyl coenzyme A and malonyl coenzyme A, which are important cellular intermediates for energy conversion and biomolecular synthesis. To obtain molecular information on ybfF esterase, which is found in a wide range of microorganisms, we elucidated the crystal structures of Ec_ybfF in complexes with small molecules at resolutions of 1.1 and 1.68 A, respectively. The structure of Ec_ybfF is composed of a globular alpha/beta hydrolase domain with a three-helical bundle cap, which is linked by a kinked helix to the alpha/beta hydrolase domain. It contains a catalytic tetrad of Ser-His-Asp-Ser with the first Ser acting as a nucleophile. The unique spatial arrangement and orientation of the helical cap with respect to the alpha/beta hydrolase domain form a substrate-binding crevice for large substrates. The helical cap is also directly involved in catalysis by providing a substrate anchor, viz., the conserved residues of Arg123 and Tyr208. The high-resolution structure of Ec_ybfF shows that the inserted helical bundle structure and its spatial orientation with respect to the alpha/beta hydrolase domain are critical for creating a large inner space and constituting a specific active site, thereby providing the broad substrate spectrum toward large biomolecules.
ESTHER : Park_2008_J.Mol.Biol_376_1426
PubMedSearch : Park_2008_J.Mol.Biol_376_1426
PubMedID: 18215690
Gene_locus related to this paper: ecoli-ybff

Title : Nuclear translocation of CAM-associated protein activates transcription for long-term facilitation in Aplysia - Lee_2007_Cell_129_801
Author(s) : Lee SH , Lim CS , Park H , Lee JA , Han JH , Kim H , Cheang YH , Lee YS , Ko HG , Jang DH , Miniaci MC , Bartsch D , Kim E , Bailey CH , Kandel ER , Kaang BK
Ref : Cell , 129 :801 , 2007
Abstract : Repeated pulses of serotonin (5-HT) induce long-term facilitation (LTF) of the synapses between sensory and motor neurons of the gill-withdrawal reflex in Aplysia. To explore how apCAM downregulation at the plasma membrane and CREB-mediated transcription in the nucleus, both of which are required for the formation of LTF, might relate to each other, we cloned an apCAM-associated protein (CAMAP) by yeast two-hybrid screening. We found that 5-HT signaling at the synapse activates PKA which in turn phosphorylates CAMAP to induce the dissociation of CAMAP from apCAM and the subsequent translocation of CAMAP into the nucleus of sensory neurons. In the nucleus, CAMAP acts as a transcriptional coactivator for CREB1 and is essential for the activation of ApC/EBP required for the initiation of LTF. Combined, our data suggest that CAMAP is a retrograde signaling component that translocates from activated synapses to the nucleus during synapse-specific LTF.
ESTHER : Lee_2007_Cell_129_801
PubMedSearch : Lee_2007_Cell_129_801
PubMedID: 17512412

Title : Crystallization and preliminary X-ray diffraction analysis of ybfF, a new esterase from Escherichia coli K12 - Park_2007_Acta.Crystallogr.Sect.F.Struct.Biol.Cryst.Commun_63_1051
Author(s) : Park SY , Lee SH , Lee J , Jung CH , Kim JS
Ref : Acta Crystallographica Sect F Struct Biol Cryst Commun , 63 :1051 , 2007
Abstract : The product of the recently discovered ybfF gene, which belongs to the esterase family, does not show high sequence similarity to other esterases. To provide the molecular background to the enzymatic mechanism of the ybfF esterase, the ybfF protein from Escherichia coli K12 (Ec_ybfF) was cloned, expressed and purified. The Ec_ybfF protein was crystallized from 60% Tacsimate and 0.1 M bis-Tris propane buffer pH 7.0. Diffraction data were collected to 1.10 A resolution using synchrotron radiation. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 66.09, b = 90.71, c = 92.88 A. With two Ec_ybfF molecules in the asymmetric unit, the crystal volume per unit protein weight is 2.17 A(3) Da(-1), corresponding to a solvent content of 42%.
ESTHER : Park_2007_Acta.Crystallogr.Sect.F.Struct.Biol.Cryst.Commun_63_1051
PubMedSearch : Park_2007_Acta.Crystallogr.Sect.F.Struct.Biol.Cryst.Commun_63_1051
PubMedID: 18084091
Gene_locus related to this paper: ecoli-ybff

Title : Frequency Detection of Organophosphate Resistance Allele in Anopheles sinensis (Diptera: Culicidae) Populations by Real-time PCR Amplification of Specific Allele (rtPASA) - Baek_2006_J.Asia.Pac.Entomol_9_375
Author(s) : Baek JH , Kim HW , Lee WJ , Lee SH
Ref : Journal of Asia-Pacific Entomology , 9 :375 , 2006
Abstract : A rapid, simple and accurate real-time PASA (PCR amplification of specific allele) (rtPASA) protocol was developed and optimized for the frequency estimation of the Glyl119Ser mutation in the type-I acetylcholinesterase locus, putatively associated with organophosphate resistance, in pooled DNA samples of Anopheles sinensis, a major vector mosquito of malaria in Korea. Performance of the rtPASA protocol was evaluated by comparing with the data generated from individual genotypings of a field population. The resistance allele frequency of the population (74.4%) predicted from the linear regression line of the rtPASA agreed well with that estimated from the individual genotyping (74.1%), demonstrating its reliability and accuracy. Using this rtPASA protocol, the resistance allele frequency in 10 local populations of An. sinensis was determined to range from 74.4% to 97.2%, suggestive of the widespread organophosphate resistance in An. sinensis in Korea.
ESTHER : Baek_2006_J.Asia.Pac.Entomol_9_375
PubMedSearch : Baek_2006_J.Asia.Pac.Entomol_9_375

Title : Molecular, biochemical and histochemical characterization of two acetylcholinesterase cDNAs from the German cockroach Blattella germanica - Kim_2006_Insect.Mol.Biol_15_513
Author(s) : Kim JI , Jung CS , Koh YH , Lee SH
Ref : Insect Molecular Biology , 15 :513 , 2006
Abstract : Full length cDNAs encoding two acetylcholinesterases (AChEs; Bgace1 and Bgace2) were cloned and characterized from the German cockroach, Blattella germanica. Sequence analyses showed that both genes possess all the typical features of ace, and that Bgace1 is orthologous to the insect ace1 whereas Bgace2 is to the insect ace2. Transcript level of Bgace1 was significantly higher (c. 10 fold) than that of Bgace2 in all 11 tissues examined, suggesting that Bgace1 likely encodes a predominant AChE. Multiple AChE bands were identified by native polyacrylamide gel electrophoresis and isoelectricfocusing from various tissue preparations, among which ganglia produced distinct two major and two minor AChE bands, indicative of the presence of at least two active AChEs. B. germanica AChEs appeared to be mainly localized in the central nervous system as demonstrated by histochemical activity staining, together with quantitative analysis of Bgace transcripts. Fluorescence in situ hybridization of the 1st thoracic ganglion confirmed that Bgace1 is predominantly transcribed and further showed that its transcript is found in almost entire region of inter or motor neurones including the cell bodies and axonal/dendritic branches. Bgace2 transcript is found only in the subset of neurones, particularly in the cell body. In addition, certain neurones were observed to express Bgace1 only.
ESTHER : Kim_2006_Insect.Mol.Biol_15_513
PubMedSearch : Kim_2006_Insect.Mol.Biol_15_513
PubMedID: 16907838
Gene_locus related to this paper: blage-ACHE1 , blage-ACHE2

Title : PKA-activated ApAF-ApC\/EBP heterodimer is a key downstream effector of ApCREB and is necessary and sufficient for the consolidation of long-term facilitation - Lee_2006_J.Cell.Biol_174_827
Author(s) : Lee JA , Lee SH , Lee C , Chang DJ , Lee Y , Kim H , Cheang YH , Ko HG , Lee YS , Jun H , Bartsch D , Kandel ER , Kaang BK
Ref : Journal of Cell Biology , 174 :827 , 2006
Abstract : Long-term memory requires transcriptional regulation by a combination of positive and negative transcription factors. Aplysia activating factor (ApAF) is known to be a positive transcription factor that forms heterodimers with ApC/EBP and ApCREB2. How these heterodimers are regulated and how they participate in the consolidation of long-term facilitation (LTF) has not, however, been characterized. We found that the functional activation of ApAF required phosphorylation of ApAF by PKA on Ser-266. In addition, ApAF lowered the threshold of LTF by forming a heterodimer with ApCREB2. Moreover, once activated by PKA, the ApAF-ApC/EBP heterodimer transactivates enhancer response element-containing genes and can induce LTF in the absence of CRE- and CREB-mediated gene expression. Collectively, these results suggest that PKA-activated ApAF-ApC/EBP heterodimer is a core downstream effector of ApCREB in the consolidation of LTF.
ESTHER : Lee_2006_J.Cell.Biol_174_827
PubMedSearch : Lee_2006_J.Cell.Biol_174_827
PubMedID: 16966424

Title : PEGylated glucagon-like peptide-1 displays preserved effects on insulin release in isolated pancreatic islets and improved biological activity in db\/db mice - Lee_2006_Diabetologia_49_1608
Author(s) : Lee S , Youn YS , Lee SH , Byun Y , Lee KC
Ref : Diabetologia , 49 :1608 , 2006
Abstract : AIMS/HYPOTHESIS: The rapid degradation and clearance of glucagon-like peptide-1 (GLP-1) by the enzymes dipeptidyl peptidase-IV and neutral endopeptidase 24.11 are the main impediments to the development of GLP-1 as a potential glucose-lowering agent. In this study, new enzyme-resistant polyethylene glycol (PEG)-conjugated GLP-1 analogues were designed and examined for metabolic stability and biological potency. MATERIALS AND
METHODS: Two mono-PEGylated GLP-1 analogues, N-terminally modified N-PEG/GLP-1 and Lys-modified Lys-PEG/GLP-1, were prepared. Stability was tested in plasma and tissue extracts. In vitro insulin release studies were performed using isolated rat pancreatic islets, while in vivo glycaemic responses were measured in db/db mice.
RESULTS: The half-life of Lys-PEG/GLP-1 was 40-, 10- and 28-fold longer than that of GLP-1 in plasma, liver and kidney homogenates, respectively. Lys-PEG/GLP-1 stimulated insulin secretion in the islets in a dose- and glucose-dependent manner, and was as potent as GLP-1. In contrast, N-PEG/GLP-1 showed extended metabolic stability but had significantly lower biological activity. The administration of Lys-PEG/GLP-1 (9 nmol/kg i.p.) to non-fasted db/db mice stabilised glycaemia (p<0.001), whereas GLP-1 (9 nmol/kg) only caused small changes in glucose level. During OGTT in fasted db/db mice, Lys-PEG/GLP-1 administered at 1, 3 and 9 nmol/kg (i.p.) reduced the glucose AUC(0-3h) by 48.7+/-9.4, 55.0+/-2.9 and 63.4+/-2.5%, respectively, compared with placebo (p<0.01), whereas GLP-1 (9 nmol/kg) lowered the glucose level by 39.5+/-12.9% (p<0.01). CONCLUSIONS/INTERPRETATION: This study demonstrates that site-specific PEGylated GLP-1 analogues are resistant to degradation. The enhanced biological potencies of these analogues highlight their potential as new, GLP-1-like glucose-lowering agents.
ESTHER : Lee_2006_Diabetologia_49_1608
PubMedSearch : Lee_2006_Diabetologia_49_1608
PubMedID: 16586064

Title : Display of lipase on the cell surface of Escherichia coli using OprF as an anchor and its application to enantioselective resolution in organic solvent - Lee_2005_Biotechnol.Bioeng_90_223
Author(s) : Lee SH , Choi JI , Han MJ , Choi JH , Lee SY
Ref : Biotechnol Bioeng , 90 :223 , 2005
Abstract : We have developed a new cell surface display system using a major outer membrane protein of Pseudomonas aeruginosa OprF as an anchoring motif. Pseudomonas fluorescens SIK W1 lipase gene was fused to the truncated oprF gene by C-terminal deletion fusion strategy. The truncated OprF-lipase fusion protein was successfully displayed on the surface of Escherichia coli. Localization of the truncated OprF-lipase fusion protein was confirmed by western blot analysis, immunofluorescence microscopy, and whole-cell lipase activity. To examine the enzymatic characteristics of the cell surface displayed lipase, the whole-cell enzyme activity and stability were determined under various conditions. Cell surface displayed lipase showed the highest activity at 37 degrees C and pH 8.0. It retained over 80% of initial activity after incubation for a week in both aqueous solution and organic solvent. When the E. coli cells displaying lipases were used for enantioselective resolution of racemic 1-phenylethanol in hexane, (R)-phenyl ethyl acetate was successfully obtained with the enantiomeric excess of greater than 96% in 36 h of reaction. These results suggest that E. coli cells displaying lipases using OprF as an anchoring motif can be employed for various biotechnological applications both in aqueous and nonaqueous phases.
ESTHER : Lee_2005_Biotechnol.Bioeng_90_223
PubMedSearch : Lee_2005_Biotechnol.Bioeng_90_223
PubMedID: 15739170

Title : Identification and characterization of ace1-type acetylcholinesterase likely associated with organophosphate resistance in Plutella xylostella - Baek_2005_Pestic.Biochem.Physiol_81_164
Author(s) : Baek JH , Kim JI , Lee DW , Chung BK , Miyata T , Lee SH
Ref : Pesticide Biochemistry and Physiology , 81 :164 , 2005
Abstract : Insensitive acetylcholinesterase (AChE) was determined to be primarily involved in a prothiofos-resistant (PR) strain of diamondback moth (DBM, Plutella xylostella L.), as judged by the AChE inhibition assay using paraoxon, where the PR strain exhibited ca. 26-fold increased I50 value. Extensive sequence analysis of the previously reported ace2-type DBM AChE gene revealed no difference between the susceptible and PR strains. To elucidate the molecular basis of the prothiofos resistance mechanism mediated by insensitive AChE, we cloned and characterized a second AChE gene from DBM. The deduced amino acid sequence of the novel AChE showed the highest homology to ace1, the second copy of insect ace, and was determined in fact as the predominant AChE in DBM compared to the ace2-type with 13- to 250-fold higher transcription levels depending on different tissues. Sequence comparison of the ace1-type cDNA between the susceptible and PR strains of DBM revealed that a total of three amino acid substitutions are closely associated with the PR strain. Among these, the Gly227Ala mutation, exclusively present in the PR strain, was located at the same position of the organophosphate resistance-conferring Gly-to-Ala mutation on the ace2 of the fruit fly and house fly. This finding suggests that the Gly227Ala mutation along with two other ones on the ace1 are likely responsible for the AChE insensitivity in DBM.
ESTHER : Baek_2005_Pestic.Biochem.Physiol_81_164
PubMedSearch : Baek_2005_Pestic.Biochem.Physiol_81_164
Gene_locus related to this paper: pluxy-ACHE1

Title : Stereoselective lipases from Burkholderia sp., cloning and their application to preparation of methyl (R)-N-(2,6-dimethylphenyl)alaninate, a key intermediate for (R)-Metalaxyl - Park_2005_J.Biotechnol_120_174
Author(s) : Park OJ , Lee SH
Ref : J Biotechnol , 120 :174 , 2005
Abstract : Two microbial strains (referred to as MC 16-3 and 99-2-1) that produce extracellular lipases were isolated from soil samples and identified as Burkholderia species. The lipases were partially purified by isopropyl alcohol precipitation and gave molecular weight of 33kDa. The lipases were characterized in terms of stereoselectivity with racemic methoxyethyl (R,S)-N-(2,6-dimethylphenyl)alaninate and the genes encoding the proteins have been identified by homology alignment of lipases reported belonging to I.2 subfamily and their complete DNA sequences were determined. The lipases will be useful for the preparation of methyl (R)-N-(2,6-dimethylphenyl)alaninate, a key intermediate for the synthesis of (R)-Metalaxyl, which is one of the best-selling fungicides.
ESTHER : Park_2005_J.Biotechnol_120_174
PubMedSearch : Park_2005_J.Biotechnol_120_174
PubMedID: 16102866
Gene_locus related to this paper: 9pseu-a0a0p0s9g4 , burce-lipaa

Title : N-nitrosocarbofuran induces apoptosis in mouse brain microvascular endothelial cells (bEnd.3) - Jung_2003_J.Pharmacol.Sci_93_489
Author(s) : Jung YS , Kim CS , Park HS , Sohn S , Lee BH , Moon CK , Lee SH , Baik EJ , Moon CH
Ref : J Pharmacol Sci , 93 :489 , 2003
Abstract : In this study, we investigated whether carbofuran, a commonly used carbamate pesticide, and N-nitrosocarbofuran (NOCF), the N-nitroso metabolite of carbofuran, have cytotoxicity in mouse brain microvascular endothelial cells (bEnd.3). Results from the MTT assay in bEnd.3 cells showed that NOCF but not carbofuran caused a remarkable decrease in cell viability. The cell death induced by NOCF appeared to involve apoptosis, based on our results from annexin V staining and electron microscopy. To investigate the mechanism of the NOCF-induced cell death, we examined the effects of selective inhibitors for MAP kinase pathways, PD98059 (for MEK/ERK), SB202190 (for p38 MAP kinase), and SP600125 (for JNK), on the NOCF-induced cell death. The NOCF-induced cell death was significantly reduced by PD98059, but not by SB202190 or SP600125. NOCF increased ERK phosphorylation as early as 15 min after the treatment and this increase was maintained for 2 h. In summary, our results suggest that NOCF can induce apoptotic cell death, at least in part, through the ERK pathway in brain microvascular endothelial cells.
ESTHER : Jung_2003_J.Pharmacol.Sci_93_489
PubMedSearch : Jung_2003_J.Pharmacol.Sci_93_489
PubMedID: 14737022

Title : DNA-based genotyping techniques for the detection of point mutations associated with insecticide resistance in Colorado potato beetle Leptinotarsa decemlineata - Clark_2001_Pest.Manag.Sci_57_968
Author(s) : Clark JM , Lee SH , Kim HJ , Yoon KS , Zhang A
Ref : Pest Manag Sci , 57 :968 , 2001
Abstract : Three DNA-based genotyping techniques, bi-directional PCR amplification of specific allele (bi-PASA), single-stranded conformational polymorphism (SSCP) and minisequencing, have been developed and compared for the detection of the S291G (insensitive acetylcholinesterase) and L1014F (insensitive sodium channel) mutations associated with azinphos-methyl and permethrin resistance, respectively, in the Colorado potato beetle (Leptinotarsa decemlineata). Extraction of genomic DNA from individual neonates that were hatched from previously collected egg masses is the most efficient and reliable means to obtain suitable templates in terms of convenience, economy, speed and DNA quality. Bi-PASA, employing two allele-specific primers, appears to be the most efficient and rapid genotyping method for the simultaneous detection of both resistant/susceptible homozygous (SS, RR) and heterozygous (SR) alleles. Its resolution, however, is strongly dependent on the quality of template genomic DNA. SSCP also allows unambiguous genotyping, including the detection of heterozygous alleles, and is less dependent on template DNA quality, but requires a longer processing time. Minisequencing is amenable to a 96-well microtiter plate format for the processing of a large number of samples and allows direct detection of resistant/susceptible homozygous alleles but is not as efficient as the PASA and SSCP in detecting heterozygous alleles. In considering the advantages and disadvantages of each technique, DNA-based genotyping is best employed in combinations, with the bi-PASA as the primary method and the SSCP and minisequencing as the secondary validating methods. These methods are rugged, rapid, cost-effective and capable of resolving SS, RR and SR individuals. The availability of such DNA-based genotyping techniques, using neonate genomic DNA as templates, will enable the precise monitoring of the resistant and susceptible allele frequencies, including those of heterozygote individuals, in field populations of L. decemlineata.
ESTHER : Clark_2001_Pest.Manag.Sci_57_968
PubMedSearch : Clark_2001_Pest.Manag.Sci_57_968
PubMedID: 11695191
Gene_locus related to this paper: lepde-ACHE

Title : Permethrin Carboxylesterase Functions as Nonspecific Sequestration Proteins in the Hemolymph of Colorado Potato Beetle, - Lee_1998_Pestic.Biochem.Physiol_62_51
Author(s) : Lee SH , Clark JM
Ref : Pesticide Biochemistry and Physiology , 62 :51 , 1998
Abstract : The inhibition profiles of the pI4.8 and 4.5 carboxylesterases from the permethrin-resistant strain of Colorado potato beetle were evaluated for a variety of inhibitors and insecticides. Both carboxylesterases were determined to be serine-hydroxyl-type esterases with different inhibition specificities toward phenylmethylsulfonyl fluoride, a serine-hydroxyl proteinase inhibitor, and para-hydroxylmercuribenzoate, a cysteine-sulfhydryl group arylesterase inhibitor. The para-hydroxylmercuribenzoate-binding site appears separate from the catalytic binding site as determined by p-chloromercuribenzoate-agarose affinity chromatography of the purified pI4.5-4.8 carboxylesterases. The pI4.8 and 4.5 carboxylesterases, however, were not significantly different in their sensitivity to various insecticides. The levels of inhibition achieved by the insecticides and eserine showed a positive correlation with the hydrophobicity of the compounds, suggesting that the pI4.8 and 4.5 carboxylesterases can interact with a variety of hydrophobic compounds through nonspecific hydrophobic site(s). The kinetics of inhibition of the pI4.5-4.8 carboxylesterases elicited by permethrin and DDT are most similar to a mixed-noncompetitive type and a noncompetitive type of inhibition, respectively. Analysis of these kinetic differences indicates the presence of hydrophobic catalytic site(s) as well as hydrophobic noncatalytic site(s) that are available for the binding of esteratic (e.g., permethrin) and nonesteratic (e.g., DDT) hydrophobic insecticides, respectively. Along with a low level of permethrin hydrolysis, the hydrophobic binding nature of the pI4.5-4.8 carboxylesterases suggests that resistance to permethrin is mainly conferred by sequestration. Sequestration of insecticides by the pI4.5-4.8 carboxylesterases appears to be nonspecific and associated with the cross-resistance of the PE-R strain to other hydrophobic insecticides, such as other pyrethroids, DDT, and abamectin.
ESTHER : Lee_1998_Pestic.Biochem.Physiol_62_51
PubMedSearch : Lee_1998_Pestic.Biochem.Physiol_62_51

Title : A Point Mutation of Acetylcholinesterase Associated with Azinphosmethyl Resistance and Reduced Fitness in Colorado Potato Beetle - Zhu_1996_Pestic.Biochem.Physiol_55_100
Author(s) : Zhu KY , Lee SH , Clark JM
Ref : Pestic Biochem Physiol , 55 :100 , 1996
Abstract : A serine to glycine point mutation of acetylcholinesterase (AChE, EC was identified in an azinphosmethyl-resistant strain of Colorado potato beetle [Leptinotarsa decemlineata (Say)]. The position of the mutation corresponds to Val 238 of the Torpedo AChE and represents the first amino acid residue to form the alpha-helix, alpha-E'1. The predicted secondary structure of the mutation-containing region of AChE suggested that the transition from the turn to the alpha-helix occurs sooner in the sequence when serine is replaced by glycine. Thus, conformational changes in the AChE due to the alpha-helix deformation were expected to impinge upon both the catalytic and the peripheral binding sites, resulting in the modification of the bindings of organophosphorus insecticides and other ligands to these sites. The mutation appeared to be associated with the fitness of the beetle. The intrinsic rate of increase of the azinphosmethyl-resistant (AZ-R) strain was relatively low when the beetles were reared on the Russet Burbank potato cultivar, but was relatively high when they were reared on the NDA 1725-1 potato cultivar. Because these two potato cultivars contain different amounts of steroidal glycoalkaloids (e.g., alpha-solanine and alpha-chaconine), the different fitness of the AZ-R strain on different potato cultivars may be partially attributed to the increased sensitivity of the azinphosmethyl-resistant form of AChE to the inhibition by alpha-solanine and reduced sensitivity to alpha-chaconine as previously reported.
ESTHER : Zhu_1996_Pestic.Biochem.Physiol_55_100
PubMedSearch : Zhu_1996_Pestic.Biochem.Physiol_55_100
PubMedID: 8980034
Gene_locus related to this paper: lepde-ACHE

Title : Permethrin resistance in a near isogenic strain of Colorado potato beetle - Argentine_1995_Pestic.Biochem.Physiol_53_97
Author(s) : Argentine JA , Lee SH , Sos MA , Barry SR , Clark JM
Ref : Pesticide Biochemistry and Physiology , 53 :97 , 1995
Abstract : The mechanisms of resistance were investigated in a near isogenic permethrin-resistant strain of Colorado potato beetle (Leptinotarsa decemlineata (Say)). The near isogenic strain was bred from a Massachusetts field strain that was multiply resistant to a number of insecticides by backcrossing to a laboratory susceptible strain. Permethrin resistance was principally associated with two contributing factors, an increased level of carboxylesterase activity and a site insensitivity associated with the nervous system. Pharmacokinetically, there were no differences noted in the rate of permethrin penetration or excretion between strains. An increased level of carboxylesterase activity was associated with the permethrin-resistant strain resulting in a 1.5-fold greater hydrolytic rate of alpha-naphthyl butyrate. Additionally, the permethrin-resistant strain produced more hydrolytic metabolites of 14C-labeled permethrin when incubated under in vivo and in vitro conditions compared to the nearly isogenic susceptible strain. The increased carboxylesterase activity associated with permethrin resistance is largely membrane-associated when whole-body extracts are examined. Increased carboxylesterase activity showed a preference of alpha-naphthyl butyrate over alpha-naphthyl acetate, suggestive of a more hydrophobic catalytic center associated with the resistant form of enzyme activity. The near isogenic permethrin-resistant strain was also determined to br cross-resistant to DDT, indicating the possibility of site insensitivity as an additional mechanism involved in permethrin resistance. Time to 50% knockdown for the resistant strain was 3.6 times longer than for its nearly isogenic susceptible strain (i.e., 56 min versus 15 min, respectively). Recovery from permethrin-induced knockdown was largely attributed to enhanced oxidative metabolism of permethrin by the resistant strain. Electrophysiological recordings determined the resistant strain to be recalcitrant to neuronal hyperexcitability caused by permethrin in the susceptible strain. These findings are consistent with a nerve insensitivity factor associated with kdr and kdr-type resistances in other insects.
ESTHER : Argentine_1995_Pestic.Biochem.Physiol_53_97
PubMedSearch : Argentine_1995_Pestic.Biochem.Physiol_53_97

Title : Biochemical Mechanisms of Azinphosmethyl Resistance in Isogenic Strains of Colorado Potato Beetle - Argentine_1994_Pestic.Biochem.Physiol_48_63
Author(s) : Argentine JA , Zhu KY , Lee SH , Clark JM
Ref : Pesticide Biochemistry and Physiology , 48 :63 , 1994
Abstract : The high level of resistance to azinphosmethyl in both the azinphosmethyl-resistant (AZ-R), near-isogenic strain (136-fold) and the multiply resistant (MA-R) field strain (435-fold) of Colorado potato beetle is complex and due to multiple factors including reduced penetration, enhanced xenobiotic metabolism, and site insensitivity. A slightly reduced penetration rate was observed in the MA-R field strain. This resistance mechanism may be potentiated further by the overall rapid excretion of aziophosmethyl in Colorado potato beetle, as well as by the above-mentioned additional resistance mechanisms. Although no significant differences were noted in monooxygenase activity or in cytochrome P450 content, both resistant strains produced significantly more of the azinphosmethyl metabolites, benzazimide and desmethyl azinphosmethyl-oxon, than the SS strain under both in vivo and in vitro conditions. The AZ-R strain, which is 97% isogenic with the SS strain, showed a significant increase in activity toward chlorodinitrobenzene, indicating glutathione S-transferase involvement. However, there was no increase in azinphosmethyl metabolites in the resistant strains using an in vitro glutathione S-transferase assay. Although not directly responsible for overall resistance, increased activity of glutathione S-transferase(s) in the resistant strains may further metabolize toxic oxidative metabolites of azinphosmethyl which are present at higher levels in the resistant strains than in the SS strain. The AZ-R strain possessed an altered acetylcholinesterase with a reduced substrate affinity for acetylthiocholine. There was a significant reduction (2-fold) in the bimolecular rate constant to azinphosmethyl-oxon in the AZ-R strain compared to that in the susceptible (SS) strain. Differential sensitivity of the acetylcholinesterase activity measured in individual beetles of these two strains to azinphosmethyl-oxon and paraoxon corroborate the presence of an altered acetylcholinesterase. Additionally, this resistant form of the acetylcholinesterase is more sensitive to the inhibitory action of the steroidal glycoalkaloid, tomatine, than the form present in the SS strain. This phenomenon may be at least partly responsible for the reduced fitness associated with these resistant strains. The demonstration of multiple resistant factors used to mitigate the toxicity of azinphosmethyl corroborates the initial findings by us that this resistance was not monofactorial. The wide range of resistance mechanisms employed by CPB is in keeping with its well-recognized status as an agricultural pest that is extremely difficult to control.
ESTHER : Argentine_1994_Pestic.Biochem.Physiol_48_63
PubMedSearch : Argentine_1994_Pestic.Biochem.Physiol_48_63