Xu G

References (51)

Title : Incretin-based drugs decrease the incidence of prostate cancer in type 2 diabetics: A pooling-up analysis - Lin_2024_Medicine.(Baltimore)_103_e38018
Author(s) : Lin Y , Xu G , Li L , Xiang J , Zhai L
Ref : Medicine (Baltimore) , 103 :e38018 , 2024
Abstract : Incretin-based drugs, a class of Antidiabetic medications (ADMs) used in the treatment of type 2 diabetes, may affect the incidence of prostate cancer (PCa). But real-world evidence for this possible effect is lacking. Therefore, the aim of this study is to assess the effect of incretin-based drugs on the incidence of PCa, including glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors. We searched PubMed, Embase, and Cochrane Library databases for eligible studies through September 2023. Two independent reviewers performed screening and data extraction. We used the Cochrane Handbook for Systematic Reviews and the Newcastle-Ottawa Scale (NOS) to assess the quality of included randomized controlled trials (RCTs) and cohort studies. We did a meta-analysis of available trial data to calculate overall risk ratios (RRs) for PCa. A total of 1238 articles were identified in our search. After screening for eligibility, 7 high-quality studies met the criteria for meta-analysis, including 2 RCTs and 5 cohort studies, with a total of 1165,738 patients. Compared with the control group, we found that incretin-based drugs reduced the relative risk of PCa by 35% (95% confidence interval (CI), 0.17-0.49; P=.0006). In subgroup analysis, the RR values for GLP-1 receptor agonists and DPP-4 inhibitors were 62% (95% CI, 0.45-0.85; P=.003) and 72% (95% CI, 0.46-1.12; P=.14), respectively. Incretin-based drugs are associated with lower incidence of prostate cancer and may have a preventive effect on prostate cancer in patients with type 2 diabetes.
ESTHER : Lin_2024_Medicine.(Baltimore)_103_e38018
PubMedSearch : Lin_2024_Medicine.(Baltimore)_103_e38018
PubMedID: 38758855

Title : Toxicity comparison of benzophenone-3 and its metabolite benzophenone-8 in different tissues of zebrafish - Wang_2024_Aquat.Toxicol_268_106852
Author(s) : Wang Y , Shang Y , Liu X , Chen X , Xu G , Lu G
Ref : Aquat Toxicol , 268 :106852 , 2024
Abstract : Benzophenone-3 (BP-3) is a commonly used ultraviolet absorber that has the potential to accumulate in organisms, leading to toxicity. Benzophenone-8 (BP-8) is one of the major metabolites of BP-3. In this study, zebrafish were exposed to different concentrations of BP-3 and BP-8 (1 microg/L, 30 microg/L, and 300 microg/L) to investigate their accumulation and toxic effects in various tissues, including zebrafish brain, gut, and liver. The analysis focused on neurotoxicity, oxidative damage, inflammation, and gene expressions. The results showed that both BP-3 and BP-8 accumulated in the tissues, with the highest concentration observed in the gut, followed by the liver and brain. BP-8 exhibited a stronger ability to accumulate. In the brain, exposure to 1 microg/L of BP-3 and BP-8 promoted cortisol production, while higher exposures (30 microg/L and 300 microg/L) inhibited acetylcholinesterase activity and suppressed cortisol production. In the gut, both BP-3 and BP-8 exposures disrupted oxidative stress, inflammatory immunity, and apoptosis functions. In the liver, BP-3 and BP-8 affected hepatic metabolism, oxidative stress, apoptosis, and inflammatory immunity. Comparing gene expression in the brain, gut, and liver, it was found that BP-3 and BP-8 had a lower effect on gene expression in the brain, while the effect on the gut and liver was significantly higher. BP-8 generally had a higher effect than BP-3, which aligns with the observed accumulation pattern. These findings provide valuable insights for the risk assessment of BP-3 and BP-8 in the aquatic environment.
ESTHER : Wang_2024_Aquat.Toxicol_268_106852
PubMedSearch : Wang_2024_Aquat.Toxicol_268_106852
PubMedID: 38310667

Title : Strigolactone and gibberellin signalling coordinately regulates metabolic adaptations to changes in nitrogen availability in rice - Sun_2023_Mol.Plant__
Author(s) : Sun H , Guo X , Zhu X , Gu P , Zhang W , Tao W , Wang D , Wu Y , Zhao Q , Xu G , Fu X , Zhang Y
Ref : Mol Plant , : , 2023
Abstract : Modern semi-dwarf rice varieties of the 'Green Revolution' require a high nitrogen (N) fertilizer supply to obtain a high yield. A better understanding of the interplay between N metabolic and developmental processes is required for improved N use efficiency (NUE) and agricultural sustainability. Here, we show that strigolactones (SLs) modulate root metabolic and developmental adaptations to low N availability, which ensure efficient uptake and translocation of available N. The key repressor DWARF 53 (D53) of the SL signalling interacts with the transcription factor GROWTH-REGULATING FACTOR 4 (GRF4) and prevents GRF4 from binding to its target gene promoters. N limitation induces the accumulation of SLs, which in turn promotes SL-mediated degradation of D53, leading to the release of GRF4 and thus promoting the genes expression associated with N metabolism. N limitation also induces degradation of the rice DELLA protein SLENDER RICE 1 (SLR1) in the D14- and D53-dependent manners, and that is effective for the release of GRF4 from the competitive inhibition caused by SLR1. Our findings reveal a previously unknown mechanism underlying SL and gibberellin crosstalk in response to N availability, which advances our understanding of plant growth-metabolic coordination that can be useful to improve NUE in high-yield crops.
ESTHER : Sun_2023_Mol.Plant__
PubMedSearch : Sun_2023_Mol.Plant__
PubMedID: 36683328

Title : A dual-emission ratiometric fluorescence strategy with enzyme-based inhibition for organophosphorus pesticides determination - Xu_2023_Mikrochim.Acta_190_337
Author(s) : Xu F , Li X , Chen C , Liang Z , Xu G , Wei F , Yang J , Hu Q , Cen Y
Ref : Mikrochim Acta , 190 :337 , 2023
Abstract : A fast, eco-friendly and accurate ratiometric fluorescent strategy is presented for the determination of organophosphorus pesticides (OPs) using intrinsic dual-emission silica nanoparticles modified with Rhodamine 6G (SiNPs-Rho6G). SiNPs-Rho6G had intrinsic dual-emission at 410 and 550 nm. The substrate acetylcholine was catalyzed by acetylcholinesterase (AChE) to produce thiocholine (TCh). TCh triggered the specific reaction of Ellman's reagent 5, 5-dithiobis (2-nitrobenzoic acid) to obtain 5-thio-2-nitrobenzoic acid, which caused the decrease in fluorescence intensity of SiNPs-Rho6G at 410 nm by the inner filter effect, while the fluorescence intensity of SiNPs-Rho6G at 550 nm was not significantly changed. OPs caused the recovery of the fluorescence at 410 nm by inhibiting the activity of AChE. Thus, the quantitative detection of OPs could be achieved through utilizing the catalytic characteristic of AChE. The linear curve from 0.010 to 0.250 microg mL(-1) with a detection limit of 7 ng mL(-1) was obtained for the determination of chlorpyrifos (Cpf). The ratiometric probe was used to detect the spiked Cpf in environmental and food samples with good recoveries. Therefore, combined with the dual emission characteristics of SiNPs-Rho6G and the specificity of the enzyme, the ratio fluorescence sensing platform has potential application prospects in OPs determinations.
ESTHER : Xu_2023_Mikrochim.Acta_190_337
PubMedSearch : Xu_2023_Mikrochim.Acta_190_337
PubMedID: 37516685

Title : Rational redesign of thermophilic PET hydrolase LCCICCG to enhance hydrolysis of high crystallinity polyethylene terephthalates - Ding_2023_J.Hazard.Mater_453_131386
Author(s) : Ding Z , Xu G , Miao R , Wu N , Zhang W , Yao B , Guan F , Huang H , Tian J
Ref : J Hazard Mater , 453 :131386 , 2023
Abstract : Polyethylene terephthalate (PET)-degrading enzymes represent a promising solution to the plastic pollution. However, PET-degrading enzymes, even thermophilic PETase, can effectively degrade low-crystallinity (-8%) PETs, but exhibit weak depolymerization of more common, high-crystallinity (30-50%) PETs. Here, based on the thermophilic PETase, LCCICCG, we proposed two strategies for rational redesign of LCCICCG using the machine learning tool, Preoptem, combined with evolutionary analysis. Six single-point mutants (S32L, D18T, S98R, T157P, E173Q, N213P) were obtained that exhibit higher catalytic efficiency towards PET powder than wild-type LCCICCG at 75 degreesC. Additionally, the optimal temperature for degrading 39.07% crystalline PET increased from 65 degreesC in the wild-type LCCICCG to between 75 and 80 degreesC in the LCCICCG_I6M mutant that carries all six single-point mutations. Especially, the LCCICCG_I6M mutant has a significantly higher degradation effect on some commonly used bottle-grade plastic powders at 75-80 degreesC than that of wild type. The enzymatic digestion of ground 31.30% crystalline PET water bottles by LCCICCG_I6M yielded 31.91 +/- 0.99 mM soluble products in 24 h, which was 3.64 times that of LCCICCG (8.77 +/- 1.52 mM). Overall, this study provides a feasible route for engineering thermostable enzymes that can degrade high-crystallinity PET plastic.
ESTHER : Ding_2023_J.Hazard.Mater_453_131386
PubMedSearch : Ding_2023_J.Hazard.Mater_453_131386
PubMedID: 37043849
Gene_locus related to this paper: 9bact-g9by57

Title : Biocatalytic Cascade Synthesis of Enantioenriched Epoxides and Triols from Biomass-Derived Synthons Driven by Specifically Designed Enzymes - Grandi_2023_Chemistry__e202300697
Author(s) : Grandi E , Crotti M , Sigmund MC , Xu G , Tepper PG , Poelarends GJ
Ref : Chemistry , :e202300697 , 2023
Abstract : Multi-enzymatic cascades exploiting engineered enzymes are a powerful tool for the tailor-made synthesis of complex molecules from simple inexpensive building blocks. In this work, we engineered the promiscuous enzyme 4-oxalocrotonate tautomerase (4-OT) into an effective aldolase with 160-fold increased activity compared to 4OT wild type. Subsequently, we applied the evolved 4-OT variant to perform an aldol condensation, followed by an epoxidation reaction catalyzed by a previously engineered 4-OT mutant, in a one-pot two-step cascade for the synthesis of enantioenriched epoxides (up to 98% ee) from biomass-derived starting materials. For three chosen substrates, the reaction was performed at milligram scale with product yields up to 68% and remarkably high enantioselectivity. Furthermore, we developed a three-step enzymatic cascade involving an epoxide hydrolase for the production of chiral aromatic 1,2,3-prim,sec,sec-triols with high enantiopurity and good isolated yields. The reported one-pot, three-step cascade, with no intermediate isolation and being completely cofactor-less, provides an attractive route for the synthesis of chiral aromatic triols from biomass-based synthons.
ESTHER : Grandi_2023_Chemistry__e202300697
PubMedSearch : Grandi_2023_Chemistry__e202300697
PubMedID: 36893219

Title : Comprehensive analysis of the carboxylesterase gene reveals that NtCXE22 regulates axillary bud growth through strigolactone metabolism in tobacco - Wang_2022_Front.Plant.Sci_13_1019538
Author(s) : Wang L , Xie X , Xu Y , Li Z , Xu G , Cheng L , Yang J , Li L , Pu W , Cao P
Ref : Front Plant Sci , 13 :1019538 , 2022
Abstract : Carboxylesterases (CXE) are a class of hydrolytic enzymes with alpha/beta-folding domains that play a vital role in plant growth, development, stress response, and activation of herbicide-active substances. In this study, 49 Nicotiana tabacum L. CXE genes (NtCXEs) were identified using a sequence homology search. The basic characteristics, phylogenetic evolution, gene structure, subcellular location, promoter cis-elements, and gene expression patterns of the CXE family were systematically analyzed. RNA-seq data and quantitative real-time PCR showed that the expression level of CXEs was associated with various stressors and hormones; gene expression levels were significantly different among the eight tissues examined and at different developmental periods. As a new class of hormones, strigolactones (SLs) are released from the roots of plants and can control the germination of axillary buds.NtCXE7, NtCXE9, NtCXE22, and NtCXE24 were homologous to Arabidopsis SLs hydrolase AtCXE15, and changes in their expression levels were induced by topping and by GR24 (a synthetic analogue of strigolactone). Further examination revealed that NtCXE22-mutant (ntcxe22) plants generated by CRISPR-Cas9 technology had shorter bud outgrowth with lower SLs content. Validation of NtCXE22 was also performed in NtCCD8-OE plants (with fewer axillary buds) and in ntccd8 mutant plants (with more axillary buds). The results suggest that NtCXE22 may act as an efficient SLs hydrolase and affects axillary bud development, thereby providing a feasible method for manipulating endogenous SLs in crops and ornamental plants.
ESTHER : Wang_2022_Front.Plant.Sci_13_1019538
PubMedSearch : Wang_2022_Front.Plant.Sci_13_1019538
PubMedID: 36600915
Gene_locus related to this paper: tobac-NtCXE49 , tobac-NtCXE48 , tobac-NtCXE46 , tobac-NtCXE44 , tobac-NtCXE41 , tobac-NtCXE40 , tobac-NtCXE39 , tobac-NtCXE38 , tobac-NtCXE36 , tobac-NtCXE34 , tobac-NtCXE33 , tobac-NtCXE28 , tobac-NtCXE27 , tobac-NtCXE26 , tobac-NtCXE25 , tobac-NtCXE24 , tobac-NtCXE23 , tobac-NtCXE21 , tobac-NtCXE19 , tobac-NtCXE18 , tobac-NtCXE17 , tobac-NtCXE15 , tobac-NtCXE14 , tobac-NtCXE13 , tobac-NtCXE12 , tobac-NtCXE11 , tobac-NtCXE10 , tobac-NtCXE8 , tobac-NtCXE7 , tobac-NtCXE6 , tobac-NtCXE5 , tobac-NtCXE4 , tobac-NtCXE3 , tobac-NtCXE2 , tobac-NtCXE1 , tobac-NtCXE30 , tobac-NtCXE32 , tobac-NtCXE22 , tobac-NtCXE29 , tobac-NtCXE35 , tobac-NtCXE45

Title : Structural and mechanistic insights into enantioselectivity toward near-symmetric esters of a novel carboxylesterase RoCE - Dou_2022_Catal.Sci.Technol_12_7448
Author(s) : Dou Z , Jia P , Chen X , Wu Z , Xu G , Ni Y
Ref : Catal Sci Technol , 12 :7448 , 2022
Abstract : A novel carboxylesterase designated as RoCE was identified from Rhodococcus opacus with high activity and enantioselectivity toward asymmetric esters such as ethyl 2,2-dimethylcyclopropane-1-carboxylate (DMCPE). Moreover, RoCE could catalyze the enantioselective resolution of near-symmetric oxyheterocyclic esters such as ethyl tetrahydro-2H-pyran-2-carboxylate (THPCE), which are generally regarded as 'hard-to-be-discriminated' by chemical and biological catalysts. The crystal structure of RoCE was resolved at a resolution of 1.78 A. Theozyme calculation, MD simulations and pre-reaction state analysis were performed to clarify the molecular basis for the enantioselectivity toward oxyheterocyclic carboxylic acid esters with a nearly symmetric structure. F166 plays an important role in manipulating the enantioselective recognition of (S)- and (R)-DMCPE through steric effect. The intrinsic symmetric structure of (S)- and (R)-THPCE is mainly responsible for the relatively lower enantioselectivity than DMCPE. By introducing hydrogen bond interactions, a mutant M144T was successfully obtained with an E value of 2.44-fold that of WT. MD simulations further prove the increased enantioselectivity of M144T in terms of pre-reaction state and binding free energy. This study provides a novel carboxylesterase and important molecular insights into the enantioselectivity of carboxylesterase toward heterocyclic carboxylic acid esters with a nearly symmetric structure, which will facilitate further engineering of the enantioselectivity of carboxylesterase.
ESTHER : Dou_2022_Catal.Sci.Technol_12_7448
PubMedSearch : Dou_2022_Catal.Sci.Technol_12_7448
PubMedID:
Gene_locus related to this paper: rhoop-RoCE

Title : Inhibitors of soluble epoxide hydrolase on acute lung injury: a meta-analysis of preclinical studies - Tao_2022_Inflammopharmacology__
Author(s) : Tao W , Xu G , Luo Y , Li PS
Ref : Inflammopharmacology , : , 2022
Abstract : INTRODUCTION: This study investigated the effects of soluble epoxide hydrolase (sEH) inhibitors on acute lung injury (ALI) using the measure of meta-analysis. METHODS: Relative publications were systematic reviewed and retrieved by searching electronic databases including the Cochrane Library, PubMed, China National Knowledge Infrastructure, Wanfang Data, and Google Scholar. RESULTS: Seven animal studies were included in this meta-analysis. Our result showed that the lung injury scores (SMD = - 2.31, 95% CI - 3.50 to - 1.12) and lung wet to dry weight ratios (WMD-1.44, 95% CI - 1.69 to - 1.18) were reduced in sEH inhibitors-treated animals compared with control. The mortality was improved by sEH inhibitors at 48 h (RR = 0.62, 95% CI 0.42 to 0.92), 72 h, and 120 h, but not at 24 h (RR = 0.59, 95% CI 0.35 to 1.01) and 96 h, after induction of ALI model. CONCLUSIONS: The sEH inhibitor is a potent candidate of pharmacological agents for ALI/acute respiratory distress syndrome, as its effects on improvement of lung injury and mortality in preclinical researches.
ESTHER : Tao_2022_Inflammopharmacology__
PubMedSearch : Tao_2022_Inflammopharmacology__
PubMedID: 36085400

Title : Integrative Analysis of Transcriptome and Metabolome Reveals Molecular Responses in Eriocheir sinensis with Hepatopancreatic Necrosis Disease - Zhan_2022_Biology.(Basel)_11_
Author(s) : Zhan M , Wen L , Zhu M , Gong J , Xi C , Wen H , Xu G , Shen H
Ref : Biology (Basel) , 11 : , 2022
Abstract : Hepatopancreatic necrosis disease (HPND) is a highly lethal disease that first emerged in 2015 in Jiangsu Province, China. So far, most researchers believe that this disease is caused by abiotic factors. However, its true pathogenic mechanism remains unknown. In this study, the effects of HPND on the metabolism and other biological indicators of the Chinese mitten crab (Eriocheir sinensis) were evaluated by integrating transcriptomics and metabolomics. Our findings demonstrate that the innate immunity, antioxidant activity, detoxification ability, and nervous system of the diseased crabs were affected. Additionally, metabolic pathways such as lipid metabolism, nucleotide metabolism, and protein metabolism were dysregulated, and energy production was slightly increased. Moreover, the IL-17 signaling pathway was activated and high levels of autophagy and apoptosis occurred in diseased crabs, which may be related to hepatopancreas damage. The abnormal mitochondrial function and possible anaerobic metabolism observed in our study suggested that functional hypoxia may be involved in HPND progression. Furthermore, the activities of carboxylesterase and acetylcholinesterase were significantly inhibited, indicating that the diseased crabs were likely stressed by pesticides such as pyrethroids. Collectively, our findings provide new insights into the molecular mechanisms altered in diseased crabs, as well as the etiology and pathogenic mechanisms of HPND.
ESTHER : Zhan_2022_Biology.(Basel)_11_
PubMedSearch : Zhan_2022_Biology.(Basel)_11_
PubMedID: 36138745

Title : Highly Sensitive Detection of the Insecticide Azamethiphos by Tris(2,2'-bipyridine)ruthenium(II) Electrogenerated Chemiluminescence - Barkae_2022_Sensors.(Basel)_22_
Author(s) : Barkae TH , Zeid AM , Xu G
Ref : Sensors (Basel) , 22 : , 2022
Abstract : Azamethiphos (AZA) is an insecticide and neurotoxic agent that causes the inhibition of acetylcholinesterase (AChE). AChE is a vital enzyme for neurotransmission because it metabolizes acetylcholine neurotransmitter at the synaptic cleft and terminates synaptic transmission. It is worth mentioning that organophosphates and carbamates inhibit AChE. These AChE inhibitors bind to the active site of the enzyme and inactivate it, leading to paralysis and death. Herein, for the first time, we develop a sensitive, low-cost, and rapid electrogenerated chemiluminescence (ECL) system for the detection of AZA. The designed ECL sensor was applied for the highly sensitive detection of AZA with a wide dynamic range (from 0.1 microM to 1000 microM) and low detection limit of 0.07 microM (S/N = 3). The practical utility of the sensor demonstrates high recoveries (96-102%) in real samples of lake water and wastewater.
ESTHER : Barkae_2022_Sensors.(Basel)_22_
PubMedSearch : Barkae_2022_Sensors.(Basel)_22_
PubMedID: 35408132

Title : Unlocking New Reactivities in Enzymes by Iminium Catalysis - Xu_2022_Angew.Chem.Int.Ed.Engl_61_e202203613
Author(s) : Xu G , Poelarends GJ
Ref : Angew Chem Int Ed Engl , 61 :e202203613 , 2022
Abstract : The application of biocatalysis in conquering challenging synthesis requires the constant input of new enzymes. Developing novel biocatalysts by absorbing catalysis modes from synthetic chemistry has yielded fruitful new-to-nature enzymes. Organocatalysis was originally bio-inspired and has become the third pillar of asymmetric catalysis. Transferring organocatalytic reactions back to enzyme platforms is a promising approach for biocatalyst creation. Herein, we summarize recent developments in the design of novel biocatalysts that adopt iminium catalysis, a fundamental branch in organocatalysis. By repurposing existing enzymes or constructing artificial enzymes, various biocatalysts for iminium catalysis have been created and optimized via protein engineering to promote valuable abiological transformations. Recent advances in iminium biocatalysis illustrate the power of combining chemomimetic biocatalyst design and directed evolution to generate useful new-to-nature enzymes.
ESTHER : Xu_2022_Angew.Chem.Int.Ed.Engl_61_e202203613
PubMedSearch : Xu_2022_Angew.Chem.Int.Ed.Engl_61_e202203613
PubMedID: 35524737

Title : Genetic manipulation of the interconversion between diacylglycerols and triacylglycerols in Rhodosporidium toruloides - Zhang_2022_Front.Bioeng.Biotechnol_10_1034972
Author(s) : Zhang Y , Zhang S , Chu Y , Zhang Q , Zhou R , Yu D , Wang S , Lyu L , Xu G , Zhao ZK
Ref : Front Bioeng Biotechnol , 10 :1034972 , 2022
Abstract : The basidiomycetous yeast Rhodosporidium toruloides (R. toruloides) is an excellent producer for neutral lipids, including triacylglycerols (TAG). Partially because genetic tools for this yeast were less developed, limited efforts were shown to explore its capacity for the production of higher-value lipids such as diacylglycerols (DAG). Here, four genes linked to the interconversion between DAG and TAG were manipulated to promote the production of DAG and free fatty acids (FFA). Among them, three TAG synthesis-related genes, DGA1, LRO1, and ARE1, were down-regulated successively via the RNA interference technology, and an endogenous TAG lipase encoded by TGL5 was fused with LDP1 and over-expressed to convert TAG into DAG and FFA. Results showed that those engineered R. toruloides strains grew normally under nutrient-rich conditions but notably slower than the parental strain NP11 in the lipid production stage. When cultivated in nitrogen-limited media, engineered strains were able to produce total lipids with improved contents of DAG and FFA by up to two-fold and three-fold, respectively. Further correlation analysis between lipid composition and cell density indicated that the formation of TAG correlated positively with cell growth; however, other lipids including DAG did negatively. This study offered valuable information and strains to engineer R. toruloides for advanced production of fatty acid derivatives.
ESTHER : Zhang_2022_Front.Bioeng.Biotechnol_10_1034972
PubMedSearch : Zhang_2022_Front.Bioeng.Biotechnol_10_1034972
PubMedID: 36394004

Title : Accelerated Solvent Extraction of Antioxidant Compounds from Gardeniae Fructus and Its Acetylcholinesterase Inhibitory and PC12 Cell Protective Activities - Fan_2021_Foods_10_
Author(s) : Fan Y , Li X , Ding L , Zhou W , Xu G , Wang Y , Zhang Y , Ni Q
Ref : Foods , 10 : , 2021
Abstract : Gardeniae fructus is a common neuroprotective medicinal food in China, however the extraction efficiency and mixture activities are rarely mentioned. In this study, accelerated solvent extraction (ASE) parameters were optimized by a response surface methodology to extract antioxidants from Gardeniae fructus. Neuroprotective activity was evaluated using H(2)O(2) and amyloid-beta(25-35) peptide-treated PC12 cells. By comparing with three other extract methods (i.e., heated refluxing extraction (HRE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE)), it was found that the yield (35.10%), total iridoids (27.69%), total flavonoid (6.12%) content, antioxidant activities (IC(50) on DPPH, 164.46 microg/mL; FRAP value 4703.54 micromol/L), and acetylcholinesterase inhibitory ability (IC(50) 92.58 microg/mL) of ASE extract under the optimal condition (150 degreesC temperature, 10 min static time, 60% ethanol, 2 extract cycles) were significantly higher than other extract methods. The strongest ability to protect PC12 cells from damage was also present in ASE extract, as evidenced by decreasing lactate dehydrogenase and malondialdehyde levels, elevating superoxide dismutase and glutathioneperoxidase activities. Compositional analysis indicated that the extremely high crocetin level in ASE extract (1.30 microg/mg) may offer great potential. Our results indicated that ASE is a proper extraction method that could offer great potential for finding the neuroprotective ability of Gardeniae fructus for the treatment of AD.
ESTHER : Fan_2021_Foods_10_
PubMedSearch : Fan_2021_Foods_10_
PubMedID: 34829086

Title : Protein engineering of stable IsPETase for PET plastic degradation by Premuse - Meng_2021_Int.J.Biol.Macromol_180_667
Author(s) : Meng X , Yang L , Liu H , Li Q , Xu G , Zhang Y , Guan F , Zhang W , Wu N , Tian J
Ref : Int J Biol Macromol , 180 :667 , 2021
Abstract : Poly(ethylene terephthalate) (PET) is used widely by human beings, but is very difficult to degrade. Up to now, the PET degradation effect of PETase from Ideonella sakaiensis 201-F6 (IsPETase) variants with low stability and activity was not ideal. In this study, a mutation design tool, Premuse, was developed to integrate the sequence alignment and quantitative selection of the preferred mutations based on natural sequence evolution. Ten single point mutants were selected from 1486 homologous sequences using Premuse, and then two mutations (W159H and F229Y) with improved stability were screened from them. The derived double point mutant, W159H/F229Y, exhibited a strikingly enhanced enzymatic performance. Its T(m) and catalytic efficiency values (k(cat)/K(m)) respectively increased by 10.4 degreesC and 2.0-fold using p-NPP as the substrate compared with wild type. The degradation activity for amorphous PET was increased by almost 40-fold in comparison with wild type at 40 degreesC in 24 h. Additionally, the variant could catalyze biodegradation of PET bottle preform at a mean rate of 23.4 mg(PET)/h/mg(enzyme). This study allowed us to design the mutation more efficiently, and provides a tool for achieving biodegradation of PET pollution under mild natural environments.
ESTHER : Meng_2021_Int.J.Biol.Macromol_180_667
PubMedSearch : Meng_2021_Int.J.Biol.Macromol_180_667
PubMedID: 33753197
Gene_locus related to this paper: idesa-peth

Title : Diterpenoid Alkaloids from the Aerial Parts of Aconitum flavum Hand.-Mazz - Zhang_2021_Nat.Prod.Bioprospect__
Author(s) : Zhang N , Xia F , Li SY , Nian Y , Wei LX , Xu G
Ref : Nat Prod Bioprospect , : , 2021
Abstract : Sixteen diterpenoid alkaloids (DAs), including six aconitine-type alkaloids (5 and 9 - 13), seven 7,17-seco-aconitine-type alkaloids (1 - 4, 6 - 8), two napelline-type alkaloids (14 and 15) as well as one veatchine-type alkaloid (16), were isolated from the aerial parts of Aconitum flavum Hand.-Mazz. In which, flavumolines A - D (1 - 4) were four new ones, and flavumoline E (5) was reported as natural compound for the first time. Their chemical structures were elucidated by the analysis of extensive spectroscopic data. The inhibitory activities of these isolates on Ca(v)3.1 low voltage-gated Ca(2+) channel, NO production in LPS-activated RAW264.7cells, five human tumor cell lines, as well as acetylcholinesterase (AChE) were tested.
ESTHER : Zhang_2021_Nat.Prod.Bioprospect__
PubMedSearch : Zhang_2021_Nat.Prod.Bioprospect__
PubMedID: 33861417

Title : Kinetic Resolution of Nearly Symmetric 3-Cyclohexene-1-carboxylate Esters Using a Bacterial Carboxylesterase Identified by Genome Mining - Dou_2021_Org.Lett__
Author(s) : Dou Z , Chen X , Niwayama S , Xu G , Ni Y
Ref : Org Lett , : , 2021
Abstract : A new bacterial carboxylesterase (CarEst3) was identified by genome mining and found to efficiently hydrolyze racemic methyl 3-cyclohexene-1-carboxylate (rac-CHCM) with a nearly symmetric structure for the synthesis of (S)-CHCM. CarEst3 displayed a high substrate tolerance and a stable catalytic performance. The enantioselective hydrolysis of 4.0 M (560 g.L(-1)) rac-CHCM was accomplished, yielding (S)-CHCM with a >99% ee, a substrate to catalyst ratio of 1400 g.g(-1), and a space-time yield of 538 g.L(-1).d(-1).
ESTHER : Dou_2021_Org.Lett__
PubMedSearch : Dou_2021_Org.Lett__
PubMedID: 33797267
Gene_locus related to this paper: 9gamm-a0a3b7mcl8

Title : Protein tyrosine phosphatase 1B (PTP1B) inhibitorsfrom the deep-sea fungus Penicillium chrysogenum SCSIO 07007 - Han_2020_Bioorg.Chem_96_103646
Author(s) : Han W , Cai J , Zhong W , Xu G , Wang F , Tian X , Zhou X , Liu Q , Liu Y , Wang J
Ref : Bioorg Chem , 96 :103646 , 2020
Abstract : Three new compounds, including two new 3,4,6-trisubstituted alpha-pyrone derivatives, chrysopyrones A and B (1 and 2), and one new indolyl diketopiperazine derivative, penilline C (3), along with twelve known compounds (4-15), were isolated and identified from the fungus Penicillium chrysogenum SCSIO 07007, separated from deep-sea hydrothermal vent environment sample collected from the Western Atlantic. Their structures and absolute configurations were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. All of the isolated compounds (1-15) were evaluated for their cytotoxic, antibacterial activities and enzyme inhibitory activities against acetylcholinesterase (AChE), alpha-glycosidase, and protein tyrosine phosphatase 1B (PTP1B). Among them, new compounds chrysopyrones A and B (1 and 2) displayed obvious inhibitory activities against PTP1B with IC50 values of 9.32 and 27.8 mug/mL, respectively. Furthermore, molecular docking was performed to investigate the inside perspective of the action in PTP1B enzyme.
ESTHER : Han_2020_Bioorg.Chem_96_103646
PubMedSearch : Han_2020_Bioorg.Chem_96_103646
PubMedID: 32036160

Title : Rationally design and chemical modification: Getting a new and efficient biocatalyst for Henry reaction - Yu_2020_Enzyme.Microb.Technol_142_109695
Author(s) : Yu Z , Zhang Q , Tang H , Xu G
Ref : Enzyme Microb Technol , 142 :109695 , 2020
Abstract : A robust biocatalyst for green Henry reaction was achieved. Based on the fact that Henry reaction requires a base for proton transfer, we firstly proposed that the catalytic triad of lipase could play this role. The distance between the substrate and the catalytic center and the surrounding amino acid interaction network were used as the criterion. Benzaldehyde and nitromethane were used as the model reaction, RNL (Lipase from Rhizopus niveus) was considered to be the best Henry reaction catalyst via a molecular dynamics simulation. Then experiments demonstrated that RNL has a yield of 48 % using model substrate in water. Further, in order to increase product yield, the chemical modifier 1, 2-cyclohexanedione (CHD) was used to modify Arg on RNL. As a result, RNL (CHD) increased the activity of catalyzing Henry reaction and had a broad spectrum of substrates, the yield of the product was as high as 67-99 %.
ESTHER : Yu_2020_Enzyme.Microb.Technol_142_109695
PubMedSearch : Yu_2020_Enzyme.Microb.Technol_142_109695
PubMedID: 33220873
Gene_locus related to this paper: rhidl-lipas

Title : A novel carboxylesterase from Acinetobacter sp. JNU9335 for efficient biosynthesis of Edoxaban precursor with high substrate to catalyst ratio - Dou_2020_Bioresour.Technol_317_123984
Author(s) : Dou Z , Xu G , Ni Y
Ref : Bioresour Technol , 317 :123984 , 2020
Abstract : A novel carboxylesterase AcEst1 was identified from Acinetobacter sp. JNU9335 with high efficiency in the biosynthesis of chiral precursor of Edoxaban through kinetic resolution of methyl 3-cyclohexene-1-carboxylate (CHCM). Sequence analysis revealed AcEst1 belongs to family IV of esterolytic enzymes and exhibits <40% identities with known carboxylesterases. The optimum pH and temperature of recombinant AcEst1 are 8.0 and 40 degC. Substrate spectrum analysis indicated that AcEst1 prefers substrates with short acyl and alcohol groups. AcEst1 was highly active in the hydrolysis of CHCM with k(cat) of 1153 s(-1) and displayed high substrate tolerance. As much as 2.0 M (280 g.L(-1)) CHCM could be enantioselectively hydrolyzed into (S)-CHCM by merely 0.08 g.L(-1)AcEst1 with ee(s) of >99% (S) and substrate to catalyst ratio (S/C) of 3500 g.g(-1). These results indicate that the novel AcEst1 is a promising biocatalyst in the synthesis of chiral carboxylic acids.
ESTHER : Dou_2020_Bioresour.Technol_317_123984
PubMedSearch : Dou_2020_Bioresour.Technol_317_123984
PubMedID: 32827974
Gene_locus related to this paper: 9gamm-a0a7h9sp49

Title : A ratiometric fluorescence probe based on carbon dots for discriminative and highly sensitive detection of acetylcholinesterase and butyrylcholinesterase in human whole blood - Xu_2019_Biosens.Bioelectron_131_232
Author(s) : Xu X , Cen Y , Xu G , Wei F , Shi M , Hu Q
Ref : Biosensors & Bioelectronics , 131 :232 , 2019
Abstract : A ratiometric fluorescence probe based on carbon dots (CDs) was developed for discriminative and highly sensitive detection of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in human whole blood. When o-phenylenediamine (OPD) was oxidized by Cu(2+), the product 2,3-diaminophenazine (oxOPD) could effectively quench the fluorescence of CDs at 460nm due to the inner filter effect and gave rise to a new emission peak at 570nm. The AChE or BChE catalyzed hydrolysis reaction of acetylthiocholine or butyrylthiocholine to generate thiocholine, whose sulfhydryl group strongly captured Cu(2+) to inhibit the oxidization of OPD, thus effectively preserving the natural fluorescence emission of CDs. The resulting fluorescence intensity ratio served as the signal output of the probe for cholinesterases (ChEs) activity sensing. The activities of AChE and BChE were determined to range from 0.2 to 14.0 U L(-1) and from 0.1 to 5.0 U L(-1), with detection limits of 0.1 U L(-1) and 0.04 U L(-1), respectively. Additionally, the IC50 of tacrine and ethopropazine for the inhibition of AChE and BChE were estimated to be 29.8nM and 132.6nM, respectively. Moreover, the probe was successfully applied to the discriminative determination of AChE and BChE in human whole blood without any pretreatment. These results suggested that the proposed strategy provided a discriminative, sensitive and robust analytical platform for ChEs clinical diagnostics and drug screening.
ESTHER : Xu_2019_Biosens.Bioelectron_131_232
PubMedSearch : Xu_2019_Biosens.Bioelectron_131_232
PubMedID: 30849722

Title : Systematic exploration of Astragalus membranaceus and Panax ginseng as immune regulators: Insights from the comparative biological and computational analysis - Liu_2019_Phytomedicine__153077
Author(s) : Liu J , Nile SH , Xu G , Wang Y , Kai G
Ref : Phytomedicine , :153077 , 2019
Abstract : BACKGROUND: Immune system plays a decisive role for defending various pathogenic microorganisms. Astragalus membranaceus (AM) and Panax ginseng (PG) are two tonic herbs used in traditional Chinese medicine (TCM) as immune booster and help to control diseases with their healthy synergistic effect on immune system. PURPOSE: This study was aimed to investigate the promote effect and molecular mechanisms of AM and PG on immune system as booster and to control the target diseases using animal and computational systematic study. METHODS: Computational models including absorption, distribution, metabolism, and elimination (ADME) with weighted ensemble similarity (WES) algorithm-based models and ClueGo network analysis were used to find the potential bioactive compounds targets and pathways, which were responsible for immune regulation. Viscera index analysis, proliferation activity of splenic lymphocytes and cytotoxic activity of NK cells assays were performed to validate the effect of AM and PG on immune system of long-term administrated mice. Metabonomic study of mice plasma was conducted to investigate effect of AM and PG on the endogenous metabolic perturbations, together with correlation analysis. RESULTS: AM and PG simultaneously showed the ability to strengthen the immune system function including enhancement of spleen and thymus index, proliferation of splenic lymphocytes and cytotoxic activity of NK cells. Besides, the different molecular mechanisms of AM and PG on immune regulation were also investigated by analyzing the potential bioactive compounds, enzymes actions and pathways. Quercetin, formononetin and kaempferol were the main immune-related compounds in AM, while ginsenoside Ra1, ginsenoside Rh1 and kaempferol in PG. About 10 target proteins were found close to immune regulation, including acetylcholinesterase (ACHE, common target in AM and PG), sphingosine kinase 1(SPHK1), cytidine deaminase (CDA), and Choline O-acetyltransferase (CHAT). Glycerophospholipid metabolism was regulated in both AM and PG groups. Pyrimidine metabolism and sphingolipid metabolism were considered as the special pathway in AM groups. Energy metabolism and glycerolipid metabolism were the special pathways in PG groups. CONCLUSION: A novel comprehensive molecular mechanism analysis method was established and applied to clarify the scientific connotation of AM and PG as immune regulation, with similar herbal tonic effect provided in clinical practice of TCM, which can provide a new line of research for drug development (immune booster) using AM and PG.
ESTHER : Liu_2019_Phytomedicine__153077
PubMedSearch : Liu_2019_Phytomedicine__153077
PubMedID: 31477352

Title : Neuroprotective potential of ketamine prevents developing brain structure impairment and alteration of neurocognitive function induced via isoflurane through the PI3K\/AKT\/GSK-3beta pathway - Wang_2019_Drug.Des.Devel.Ther_13_501
Author(s) : Wang R , Zhang Z , Kumar M , Xu G , Zhang M
Ref : Drug Des Devel Ther , 13 :501 , 2019
Abstract : Background: The aim of the current experimental study was to scrutinize the neuroprotective effect of ketamine on the isoflurane (iso)-induced cognitive dysfunction in rats via phosphoinositide 3 kinase (PI3K)/protein kinase B (AKT)/glycogen synthase kinase 3beta (GSK-3beta) pathway. Materials and methods: Sprague-Dawley rats were used for the current experimental study. The rats were divided into six groups and rats were treated with ketamine and memantine. For the estimation of cognitive function study, we used the Morris water test. Pro-inflammatory cytokines such as IL-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and caspase-6; the antioxidant parameters malondialdehyde, glutathione, superoxide dismutase, catalase, and protein carbonyl; acetylcholinesterase, amyloid beta, and brain-derived neurotrophic factor were estimated, respectively. The protein expression of AKT, GSK-3beta, p21WAF1/CIP1, and p53 was also estimated, respectively. Results: Ketamine significantly enhanced cognitive function and showed anti-inflammatory and antioxidant effects, and exhibited the neuroprotective effect of ketamine against the isoflurane-induced cognitive impairment. Additionally, ketamine significantly (P<0.005) suppressed IL-1beta, TNF-alpha, IL-6, caspase-6 and p21WAF1/CIP1, p53 expression and up-regulated the PI3K/AKT/GSK-3beta expression in the group of iso-induced rats. Conclusion: We can conclude that ketamine prevented the cognitive impairment induced by isoflurane anesthesia through anti-apoptotic, anti-inflammatory, and antioxidant effects via the PI3K/AKT/GSK-3beta pathway.
ESTHER : Wang_2019_Drug.Des.Devel.Ther_13_501
PubMedSearch : Wang_2019_Drug.Des.Devel.Ther_13_501
PubMedID: 30787593

Title : Improvement of Learning and Memory Induced by Cordyceps Polypeptide Treatment and the Underlying Mechanism - Yuan_2018_Evid.Based.Complement.Alternat.Med_2018_9419264
Author(s) : Yuan G , An L , Sun Y , Xu G , Du P
Ref : Evid Based Complement Alternat Med , 2018 :9419264 , 2018
Abstract : Our previous research revealed that Cordyceps militaris can improve the learning and memory, and although the main active ingredient should be its polypeptide complexes, the underlying mechanism of its activity remains poorly understood. In this study, we explored the mechanisms by which Cordyceps militaris improves learning and memory in a mouse model. Mice were given scopolamine hydrobromide intraperitoneally to establish a mouse model of learning and memory impairment. The effects of Cordyceps polypeptide in this model were tested using the Morris water maze test; serum superoxide dismutase activity; serum malondialdehyde levels; activities of acetyl cholinesterase, Na+-k+-ATPase, and nitric oxide synthase; and gamma aminobutyric acid and glutamate contents in brain tissue. Moreover, differentially expressed genes and the related cellular signaling pathways were screened using an mRNA expression profile chip. The results showed that the genes Pik3r5, Il-1beta, and Slc18a2 were involved in the effects of Cordyceps polypeptide on the nervous system of these mice. Our findings suggest that Cordyceps polypeptide may improve learning and memory in the scopolamine-induced mouse model of learning and memory impairment by scavenging oxygen free radicals, preventing oxidative damage, and protecting the nervous system.
ESTHER : Yuan_2018_Evid.Based.Complement.Alternat.Med_2018_9419264
PubMedSearch : Yuan_2018_Evid.Based.Complement.Alternat.Med_2018_9419264
PubMedID: 29736181

Title : Soluble Epoxide Hydrolase Plays a Vital Role in Angiotensin II-Induced Lung Injury in Mice - Tao_2018_Shock_50_589
Author(s) : Tao W , Li PS , Xu G , Luo Y , Shu YS , Tao YZ , Yang LQ
Ref : Shock , 50 :589 , 2018
Abstract : BACKGROUND: Angiotensin II plays a vital role in the pathogenesis of acute respiratory distress syndrome (ARDS). However, its mechanism is not well defined. Angiotensin II upregulates the expression of soluble epoxide hydrolase (sEH; Ephx2). sEH is suggested as a potential pharmacologic target for ARDS. The present study investigates whether the sEH is involved in the angiotensin II-triggered pulmonary inflammation and edema using an angiotensin II-induced lung injury animal model. METHODS: Lung injury was induced by angiotensin II intratracheally instillation in wild-type or Ephx2 deficient mice. RESULTS: sEH activities were markedly increased in wild-type mice treated with angiotensin II. Angiotensin II markedly increased the levels of tumor necrosis factor-alpha and interleukin-1beta in bronchoalveolar lavage fluid, worsened alveolar capillary protein leak and lung histological alterations, and elevated activity of activator protein-1 and nuclear factor-kappaB. However, these changes were significantly improved in Ephx2 deficient mice. Moreover, Losartan, an angiotensin II receptor 1 antagonist, abolished the sEH induction and improved mortality. CONCLUSIONS: Angiotensin II-induced lung injury was improved in sEH gene deleted mice. The angiotensin II-triggered pulmonary inflammation is mediated, at least in part, through the sEH.
ESTHER : Tao_2018_Shock_50_589
PubMedSearch : Tao_2018_Shock_50_589
PubMedID: 29206762

Title : Protein Discovery: Combined Transcriptomic and Proteomic Analyses of Venom from the Endoparasitoid Cotesia chilonis (Hymenoptera: Braconidae) - Teng_2017_Toxins.(Basel)_9_
Author(s) : Teng ZW , Xiong SJ , Xu G , Gan SY , Chen X , Stanley D , Yan ZC , Ye GY , Fang Q
Ref : Toxins (Basel) , 9 : , 2017
Abstract : Many species of endoparasitoid wasps provide biological control services in agroecosystems. Although there is a great deal of information on the ecology and physiology of host/parasitoid interactions, relatively little is known about the protein composition of venom and how specific venom proteins influence physiological systems within host insects. This is a crucial gap in our knowledge because venom proteins act in modulating host physiology in ways that favor parasitoid development. Here, we identified 37 possible venom proteins from the polydnavirus-carrying endoparasitoid Cotesia chilonis by combining transcriptomic and proteomic analyses. The most abundant proteins were hydrolases, such as proteases, peptidases, esterases, glycosyl hydrolase, and endonucleases. Some components are classical parasitoid venom proteins with known functions, including extracellular superoxide dismutase 3, serine protease inhibitor and calreticulin. The venom contains novel proteins, not recorded from any other parasitoid species, including tolloid-like proteins, chitooligosaccharidolytic beta-N-acetylglucosaminidase, FK506-binding protein 14, corticotropin-releasing factor-binding protein and vascular endothelial growth factor receptor 2. These new data generate hypotheses and provide a platform for functional analysis of venom components.
ESTHER : Teng_2017_Toxins.(Basel)_9_
PubMedSearch : Teng_2017_Toxins.(Basel)_9_
PubMedID: 28417942

Title : Molecular characterization and expression profiles of nicotinic acetylcholine receptors in the rice striped stem borer, Chilo suppressalis (Lepidoptera: Crambidae) - Xu_2017_Insect.Sci_24_371
Author(s) : Xu G , Wu SF , Teng ZW , Yao HW , Fang Q , Huang J , Ye GY
Ref : Insect Sci , 24 :371 , 2017
Abstract : Nicotinic acetylcholine receptors (nAChRs) are members of the cys-loop ligand-gated ion channel (cysLGIC) superfamily, mediating fast synaptic cholinergic transmission in the central nervous system in insects. Insect nAChRs are the molecular targets of economically important insecticides, such as neonicotinoids and spinosad. Identification and characterization of the nAChR gene family in the rice striped stem borer, Chilo suppressalis, could provide beneficial information about this important receptor gene family and contribute to the investigation of the molecular modes of insecticide action and resistance for current and future chemical control strategies. We searched our C. suppressalis transcriptome database using Bombyx mori nAChR sequences in local BLAST searches and obtained the putative nAChR subunit complementary DNAs (cDNAs) via reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods. Similar to B. mori, C. suppressalis possesses 12 nAChR subunits, including nine alpha-type and three beta-type subunits. Quantitative RT-PCR analysis revealed the expression profiles of the nAChR subunits in various tissues, including the brain, subesophageal ganglion, thoracic ganglion, abdominal ganglion, hemocytes, fat body, foregut, midgut, hindgut and Malpighian tubules. Developmental expression analyses showed clear differential expression of nAChR subunits throughout the C. suppressalis life cycle. The identification of nAChR subunits in this study will provide a foundation for investigating the diverse roles played by nAChRs in C. suppressalis and for exploring specific target sites for chemicals that control agricultural pests while sparing beneficial species.
ESTHER : Xu_2017_Insect.Sci_24_371
PubMedSearch : Xu_2017_Insect.Sci_24_371
PubMedID: 26847606

Title : Effects and mechanism of cerebroprotein hydrolysate on learning and memory ability in mice - An_2016_Genet.Mol.Res_15_
Author(s) : An L , Han X , Li H , Ma Y , Shi L , Xu G , Yuan G , Sun J , Zhao N , Sheng Y , Wang M , Du P
Ref : Genet Mol Res , 15 : , 2016
Abstract : Cerebroprotein hydrolysate is an extract from porcine brain tissue that acts on the central nervous system in various ways to protect neurons and improve memory, attention, and vigilance. This study examined the effect and mechanism of cerebroprotein hydrolysate on learning and memory in mice with scopolamine-induced impairment. Mice were given an intraperitoneal injection of scopolamine hydrobromide to establish a murine model of learning and memory impairment. After 35 successive days of cerebroprotein hydrolysate treatment, their behaviors were observed in the Morris water maze and step-down test. Superoxide dismutase (SOD), Na+-K+-ATPase, and acetylcholinesterase (AChE) activity, and malondialdehyde (MDA), gamma-aminobutyric acid (GABA), and glutamic acid (Glu) levels in the brain tissue of the mice were determined, and pathological changes in the hippocampus were examined. The results of the water-maze test showed that cerebroprotein hydrolysate shortened the escape latency and increased the number of platform crossings. In the step-down test, cerebroprotein hydrolysate treatment prolonged the step-down latency and reduced the number of errors; cerebroprotein hydrolysate increased the activity of SOD, Na+-K+-ATPase, and AChE, reduced the levels of MDA, decreased the Glu/GABA ratio in brain tissue, and reduced pathological changes in the hippocampus. The results indicate that cerebroprotein hydrolysate can improve learning and memory in mice with scopolamine-induced impairment. This effect may be associated with its ability to reduce injury caused by free radicals, improve acetylcholine function, and modulate the Glu/GABA learning and memory regulation system, reducing excitotoxicity caused by Glu.
ESTHER : An_2016_Genet.Mol.Res_15_
PubMedSearch : An_2016_Genet.Mol.Res_15_
PubMedID: 27525868

Title : Cloning and characterization of a novel lipase from Stenotrophomonas maltophilia GS11: The first member of a new bacterial lipase family XVI - Li_2016_J.Biotechnol_228_30
Author(s) : Li M , Yang LR , Xu G , Wu JP
Ref : J Biotechnol , 228 :30 , 2016
Abstract : Bacterial lipases are an important group of enzymes that offer enormous potential in organic synthesis, and there is considerable interest in identifying and developing novel bacterial lipases. In previous studies, strains of the genus Stenotrophomonas were proved to be potential source of lipases, but there is little genetic information describing lipase from the genus Stenotrophomonas. We have cloned and characterized a novel lipase (LipSM54), the first lipase described from the genus Stenotrophomonas. Enzymatic study showed that LipSM54 was a cold-active, solvent-tolerant and alkaline lipase. Using bioinformatics tools, LipSM54 was found to be related only to several putative lipases from different bacterial origins, none of which could be assigned to any previously described bacterial lipase family. LipSM54 and these related putative lipases share four conserved motifs around the catalytic residues. These motifs clearly distinguish them from the known bacterial lipase families. Consequently, LipSM54 is the first characterized member of the novel bacterial lipase family.
ESTHER : Li_2016_J.Biotechnol_228_30
PubMedSearch : Li_2016_J.Biotechnol_228_30
PubMedID: 27117245
Gene_locus related to this paper: stema-s4tny8

Title : Independent Evolution of Six Families of Halogenating Enzymes - Xu_2016_PLoS.One_11_e0154619
Author(s) : Xu G , Wang BG
Ref : PLoS ONE , 11 :e0154619 , 2016
Abstract : Halogenated natural products are widespread in the environment, and the halogen atoms are typically vital to their bioactivities. Thus far, six families of halogenating enzymes have been identified: cofactor-free haloperoxidases (HPO), vanadium-dependent haloperoxidases (V-HPO), heme iron-dependent haloperoxidases (HI-HPO), non-heme iron-dependent halogenases (NI-HG), flavin-dependent halogenases (F-HG), and S-adenosyl-L-methionine (SAM)-dependent halogenases (S-HG). However, these halogenating enzymes with similar biological functions but distinct structures might have evolved independently. Phylogenetic and structural analyses suggest that the HPO, V-HPO, HI-HPO, NI-HG, F-HG, and S-HG enzyme families may have evolutionary relationships to the alpha/beta hydrolases, acid phosphatases, peroxidases, chemotaxis phosphatases, oxidoreductases, and SAM hydroxide adenosyltransferases, respectively. These halogenating enzymes have established sequence homology, structural conservation, and mechanistic features within each family. Understanding the distinct evolutionary history of these halogenating enzymes will provide further insights into the study of their catalytic mechanisms and halogenation specificity.
ESTHER : Xu_2016_PLoS.One_11_e0154619
PubMedSearch : Xu_2016_PLoS.One_11_e0154619
PubMedID: 27153321

Title : The discovery of new acetylcholinesterase inhibitors derived from pharmacophore modeling, virtual screening, docking simulation and bioassays - Zhang_2016_Mol.Biosyst_12_3734
Author(s) : Zhang Y , Zhang S , Xu G , Yan H , Pu Y , Zuo Z
Ref : Mol Biosyst , 12 :3734 , 2016
Abstract : Hyperactivity of acetylcholinesterase (AChE) in the brain is the immediate cause of Alzheimer's disease (AD), which is one of the most prevalent fatal diseases afflicting numerous older people. In this research, an in silico study was carried out to find potential AChE inhibitors from a large chemical library. With clustering and lots of comprehensive analysis, some molecules were screened using in vitro bioassays. The IC50 values against AChE ranged from 33.620 to 101.570 muM, while the inhibition ratios at 50 muM ranged from 11.37% to 77.35%. The binding mode between the inhibitor and the binding sites of AChE was studied. Four residues (Tyr133, Tyr124, Ser203 and Trp86) were suggested to be crucial because they can form hydrogen bonds with the ligand. Therefore, ZYQ1 and its derivatives might represent a promising starting point for the development of highly potent lead compounds for the treatment of AD.
ESTHER : Zhang_2016_Mol.Biosyst_12_3734
PubMedSearch : Zhang_2016_Mol.Biosyst_12_3734
PubMedID: 27801451

Title : Targeting of cancerassociated fibroblasts enhances the efficacy of cancer chemotherapy by regulating the tumor microenvironment - Li_2016_Mol.Med.Rep_13_2476
Author(s) : Li M , Yin T , Shi H , Wen Y , Zhang B , Chen M , Xu G , Ren K , Wei Y
Ref : Mol Med Rep , 13 :2476 , 2016
Abstract : Cancerassociated fibroblasts (CAFs), key components of the tumor stroma, can regulate tumorigenesis by altering the tumor microenvironment in variety of ways to promote angiogenesis, recruit inflammatory immune cells and remodel the extracellular matrix. Using a murine xenograft model of colon carcinoma, the present study observed that oxaliplatin increased the accumulation of CAFs and stimulated the production of cytokines associated with CAFs. When oxaliplatin was combined with the smallmolecule dipeptidyl peptidase inhibitor PT100, which inhibits CAFs by targeting fibroblast activation protein (FAP), the accumulation of CAFs was markedly reduced, xenograft tumor growth was significantly suppressed and the survival of the mice increased, compared to those of mice treated with oxaliplatin or PT100 alone. Furthermore, the xenograft tumor tissues of mice treated with oxaliplatin and PT100 contained lower numbers of tumorassociated macrophages and dendritic cells, expressed lower levels of cytokines associated with CAFs and had a lower density of CD31+ endothelial cells. The present study demonstrated that pharmacological inhibition of CAFs improved the response to chemotherapy, reduced the recruitment of immune tumorpromoting cells and inhibited angiogenesis. Combining chemotherapy with agents which target CAFs may represent a novel strategy for improving the efficacy of chemotherapy and reducing chemoresistance.
ESTHER : Li_2016_Mol.Med.Rep_13_2476
PubMedSearch : Li_2016_Mol.Med.Rep_13_2476
PubMedID: 26846566

Title : Strigolactones are required for nitric oxide to induce root elongation in response to nitrogen and phosphate deficiencies in rice - Sun_2016_Plant.Cell.Environ_39_1473
Author(s) : Sun H , Bi Y , Tao J , Huang S , Hou M , Xue R , Liang Z , Gu P , Yoneyama K , Xie X , Shen Q , Xu G , Zhang Y
Ref : Plant Cell Environ , 39 :1473 , 2016
Abstract : The response of the root system architecture to nutrient deficiencies is critical for sustainable agriculture. Nitric oxide (NO) is considered a key regulator of root growth, although the mechanisms remain unknown. Phenotypic, cellular and genetic analyses were undertaken in rice to explore the role of NO in regulating root growth and strigolactone (SL) signalling under nitrogen-deficient and phosphate-deficient conditions (LN and LP). LN-induced and LP-induced seminal root elongation paralleled NO production in root tips. NO played an important role in a shared pathway of LN-induced and LP-induced root elongation via increased meristem activity. Interestingly, no responses of root elongation were observed in SL d mutants compared with wild-type plants, although similar NO accumulation was induced by sodium nitroprusside (SNP) application. Application of abamine (the SL inhibitor) reduced seminal root length and pCYCB1;1::GUS expression induced by SNP application in wild type; furthermore, comparison with wild type showed lower SL-signalling genes in nia2 mutants under control and LN treatments and similar under SNP application. Western blot analysis revealed that NO, similar to SL, triggered proteasome-mediated degradation of D53 protein levels. Therefore, we presented a novel signalling pathway in which NO-activated seminal root elongation under LN and LP conditions, with the involvement of SLs.
ESTHER : Sun_2016_Plant.Cell.Environ_39_1473
PubMedSearch : Sun_2016_Plant.Cell.Environ_39_1473
PubMedID: 27194103

Title : Polycyclic Polyprenylated Acylphloroglucinol Congeners Possessing Diverse Structures from Hypericum henryi - Yang_2015_J.Nat.Prod_78_885
Author(s) : Yang XW , Li MM , Liu X , Ferreira D , Ding Y , Zhang JJ , Liao Y , Qin HB , Xu G
Ref : Journal of Natural Products , 78 :885 , 2015
Abstract : Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structural and bioactive diversity. In a systematic phytochemical investigation of Hypericum henryi, 40 PPAP-type derivatives, including the new compounds hyphenrones G-Q, were obtained. These compounds represent 12 different structural types, including four unusual skeletons exemplified by 5, 8, 10, and 17. The 12 different core structures found are explicable in terms of their biosynthetic origin. The structure of a known PPAP, perforatumone, was revised to hyphenrone A (5) by NMR spectroscopic and biomimetic synthesis methods. Several compounds exhibited inhibitory activities against acetylcholinesterase and human tumor cell lines. This study deals with the structural diversity, function, and biogenesis of natural PPAPs.
ESTHER : Yang_2015_J.Nat.Prod_78_885
PubMedSearch : Yang_2015_J.Nat.Prod_78_885
PubMedID: 25871261

Title : Discovery and expression of a Pseudomonas sp. esterase as a novel biocatalyst for the efficient biosynthesis of a chiral intermediate of pregabalin -
Author(s) : Xu F , Chen S , Xu G , Wu J , Yang L
Ref : Biotechnol Bioprocess Eng , 20 :473 , 2015
PubMedID:

Title : 1,9-seco-Bicyclic Polyprenylated Acylphloroglucinols from Hypericum uralum - Zhang_2015_J.Nat.Prod_78_3075
Author(s) : Zhang JJ , Yang XW , Liu X , Ma JZ , Liao Y , Xu G
Ref : Journal of Natural Products , 78 :3075 , 2015
Abstract : Hyperuralones C-H (1-6), six new 1,9-seco-bicyclic polyprenylated acylphloroglucinols (1,9-seco-BPAPs) derived from the normal polyprenylated acylphloroglucinols with a bicyclo[3.3.1]nonane-2,4,9-trione core, together with six known analogues, were isolated from the aerial parts of Hypericum uralum. The structures of 1-6 were elucidated on the basis of the interpretation of NMR and MS spectroscopic data. The structure of attenuatumione B, a known compound isolated from H. attenuatum, was revised to that of a 1,9-seco-BPAP by NMR spectroscopic analysis and previous biomimetic synthesis methods. The inhibitory activities of these isolates on acetylcholinesterase were tested, and compounds 1 and 2 exhibited moderate activities with IC50 values of 9.6 and 7.1 muM, respectively.
ESTHER : Zhang_2015_J.Nat.Prod_78_3075
PubMedSearch : Zhang_2015_J.Nat.Prod_78_3075
PubMedID: 26583263

Title : Introducing a salt bridge into the lipase of Stenotrophomonas maltophilia results in a very large increase in thermal stability - Wu_2015_Biotechnol.Lett_37_403
Author(s) : Wu JP , Li M , Zhou Y , Yang LR , Xu G
Ref : Biotechnol Lett , 37 :403 , 2015
Abstract : High thermostability of enzymes is a prerequisite for their biotechnological applications. An organic solvent-tolerant and cold-active lipase, from the Stenotrophomonas maltophilia, was unstable above 40 degrees C in previous studies. To increase the enzyme stability, possible hydrogen-bond networks were simulated by the introduction of a salt bridge in a highly flexible region of the protein. Compared with the wild-type lipase, a mutant lipase (G165D and F73R) showed a >900-fold improvement in half-life at 50 degrees C, with the optimal activity-temperature increasing from 35 to 90 degrees C. Therefore, the hydrogen-bond strategy is a powerful approach for improving enzyme stability through the introduction of a salt bridge.
ESTHER : Wu_2015_Biotechnol.Lett_37_403
PubMedSearch : Wu_2015_Biotechnol.Lett_37_403
PubMedID: 25257598

Title : Characterization and structure basis of Pseudomonas alcaligenes lipase's enantiopreference towards d,l-menthyl propionate - Chen_2014_J.Mol.Catal.B.Enzym_102_81
Author(s) : Chen H , Wu J , Yang L , Xu G
Ref : J Mol Catal B Enzym , 102 :81 , 2014
Abstract : In this work, a lipase from Pseudomonas alcaligenes CGMCC4405 (PaL) was cloned and expressed. It was very attractive that the recombinant PaL exhibited excellent enantioselectivity (E > 200) in the resolution of racemic d,l-menthyl propionate to produce l-menthol. The structure basis of enantiopreference is a fundamental scientific problem which needs to be resolved. In our research, molecular dynamic simulation (MD) research was employed to research the different binding modes of d and l-menthyl propionate. The results showed that when bound with slow-reacting enantiomer (d-menthyl propionate), the steric requirements of the large substituent (isopropyl) of the d-menthyl propionate force a rotation of the imidazole ring of catalytic residue His271 and further pushed the active site His271 away from its proper orientation. Moreover, the average distance between alcohol oxygen (Oalc) and HNe of catalytic His271 increased to 3.7 A, which was too far to form an essential hydrogen bond and further prevented efficient catalysis of slow enantiomer. This correlation of the distance between alcohol oxygen (Oalc) and HNe of catalytic His271 and the enantioselectivity was also confirmed by the result of site-directed mutagenesis.
ESTHER : Chen_2014_J.Mol.Catal.B.Enzym_102_81
PubMedSearch : Chen_2014_J.Mol.Catal.B.Enzym_102_81
PubMedID:
Gene_locus related to this paper: stema-s4tny8

Title : Improving Pseudomonas alcaligenes lipase's diastereopreference in hydrolysis of diastereomeric mixture of menthyl propionate by site-directed mutagenesis - Chen_2014_Biotechnol.Bioprocess.Eng_19_592
Author(s) : Chen H , Wu JP , Yang LR , Xu G
Ref : Biotechnol Bioprocess Eng , 19 :592 , 2014
Abstract : The resolutions of racemic diastereomeric mixtures of menthyl propionate was performed by Pseudomonas alcaligenes lipase (PaL) to produce (2S, 5R) L-menthol. Because of the inherently low diastereopreference of PaL, covalent docking and molecular dynamic (MD) simulations were used to investigate possible avenues of improvement. Rational site-directed mutagenesis of PaL revealed residues V180 and A272 to be the hotspots for diastereopreference. The double V180L/A272F mutant exhibited the highest degree of diastereopreference, as the diastereomeric ratio of (2S, 5R) L-menthol increased towards both (2R, 5S) L-neomenthol (dr1) and (2R, 5R) D-isoneomenthol (dr2) (diastereomeric ratios dr1 and dr2 increased to 4.65 and 2.13 times that of wild-type PaL). MD simulation analysis indicated that these mutations decrease the flexibility of the surrounding protein regions. The combination of increased steric exclusion and decreased flexibility results in less favorable binding of the non-target substrates, (2R, 5S) L-neomenthyl propionate and (2R, 5R) D-isoneomenthyl propionate, to the V180L/A272F mutant. These results confirmed and further improved our previously proposed model of the diastereomer recognition mechanism based on the combined effect of steric exclusion and regional flexibility.
ESTHER : Chen_2014_Biotechnol.Bioprocess.Eng_19_592
PubMedSearch : Chen_2014_Biotechnol.Bioprocess.Eng_19_592
PubMedID:
Gene_locus related to this paper: stema-s4tny8

Title : Bioactive Polyprenylated Acylphloroglucinol Derivatives from Hypericum cohaerens - Liu_2013_J.Nat.Prod_76_1612
Author(s) : Liu X , Yang XW , Chen CQ , Wu CY , Zhang JJ , Ma JZ , Wang H , Yang LX , Xu G
Ref : Journal of Natural Products , 76 :1612 , 2013
Abstract : Nine new polyprenylated acylphloroglucinol derivatives, hypercohins B-J (1-9), and nine known analogues were isolated from the aerial parts of Hypericum cohaerens. The structures of 1-9 were elucidated based on spectroscopic analysis, and the absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of these isolates on acetylcholinesterase and five human tumor cell lines were tested, and hypercohins B-D (1-3) exhibited moderate inhibitory activity (IC50 5.8-17.9 muM) against the tested tumor cell lines.
ESTHER : Liu_2013_J.Nat.Prod_76_1612
PubMedSearch : Liu_2013_J.Nat.Prod_76_1612
PubMedID: 23957453

Title : Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Strain Marinobacter nanhaiticus D15-8WT - Cui_2013_Genome.Announc_1_E00301
Author(s) : Cui Z , Gao W , Li Q , Xu G , Zheng L
Ref : Genome Announc , 1 : , 2013
Abstract : Marinobacter nanhaiticus strain D15-8W(T) was isolated from a phenanthrene-degrading consortium, enriched from sediment of the South China Sea. Here, we present the draft genome of strain D15-8W(T), which contains 5,358,309 bp with a G+C content of 58.53% and contains 4,829 protein-coding genes and 47 tRNA genes.
ESTHER : Cui_2013_Genome.Announc_1_E00301
PubMedSearch : Cui_2013_Genome.Announc_1_E00301
PubMedID: 23723401
Gene_locus related to this paper: 9alte-n6wxm5 , 9alte-n6wy71 , cycsp-k0c2b8 , 9alte-n6wng0 , 9alte-n6w2r7 , 9alte-n6w156 , 9alte-n6wvv7

Title : Hemolytic phospholipase Rv0183 of Mycobacterium tuberculosis induces inflammatory response and apoptosis in alveolar macrophage RAW264.7 cells - Xu_2010_Can.J.Microbiol_56_916
Author(s) : Xu G , Jia H , Li Y , Liu X , Li M , Wang Y
Ref : Can J Microbiol , 56 :916 , 2010
Abstract : The metabolic pathway of phospholipids is one of the most important physiologic pathways in Mycobacterium tuberculosis, a typical intracellular bacterium. The hemolytic phospholipase lip gene (Rv0183) is one of 24 phospholipase genes that have been demonstrated to play critical roles in the metabolism of phospholipids in M. tuberculosis. Quantitative RT-PCR and flow cytometry were used to elucidate the immunological and pathogenic implications of the Rv0183 gene on the inflammatory response following persistent expression of Rv0183 in mouse alveolar macrophage RAW264.7 cells. Our results demonstrate that a time-course-dependent ectopic expression of Rv0183 significantly elevated the expression of IL-6, NF-kappaB, TLR-2, TLR-6, TNFalpha, and MyD88 in these alveolar macrophage cells. Furthermore, the persistent expression of Rv0183 induced RAW264.7 cell apoptosis in vitro. These findings demonstrate that the expression of Rv0183 induces an inflammatory response and cell apoptosis in the host cells, suggesting that Rv0183 may play an important role in the virulence and pathogenesis of M. tuberculosis infection.
ESTHER : Xu_2010_Can.J.Microbiol_56_916
PubMedSearch : Xu_2010_Can.J.Microbiol_56_916
PubMedID: 21076482
Gene_locus related to this paper: myctu-rv0183

Title : Comparative study of properties of immobilized lipase onto glutaraldehyde-activated amino-silica gel via different methods - Yang_2010_Colloids.Surf.B.Biointerfaces_78_351
Author(s) : Yang G , Wu J , Xu G , Yang L
Ref : Colloids Surf B Biointerfaces , 78 :351 , 2010
Abstract : The enzyme-aggregate coating method was performed to immobilize Arthrobacter sp. lipase in order to achieve better catalytic properties comparable to the conventional covalent attachment and covalent attachment plus cross-linking. The glutaraldehyde-activated amino-silica gel which was synthesized by sol-gel technique was used as the support, and the catalytic characteristics of the lipase preparations were tested in the asymmetric acylation of 4-hydroxy-3-methyl-2-(2-propenyl)-2-cyclopenten-1-one (HMPC) in organic solvents. The results showed that the immobilized lipase by enzyme-aggregate coating possessed both higher activity and stability than those by other methods, e.g. it obtained an activity of 82.6 U/g and remained 42% and 93% of the original activity after incubation in vinyl acetate at 60 degrees C for 16 h and 9 times recycles, respectively, while the covalently attached lipase got an activity of 67.4 U/g and left 33% and 73% of the original under the same conditions, and the enzyme prepared by covalent attachment plus cross-linking exhibited the lowest activity yield. Moreover, excellent enantioselectivity (E > or =400) was achieved by all the three prepared lipases in our paper (E=85 for the free enzyme).
ESTHER : Yang_2010_Colloids.Surf.B.Biointerfaces_78_351
PubMedSearch : Yang_2010_Colloids.Surf.B.Biointerfaces_78_351
PubMedID: 20399626

Title : Increased lipolysis in adipose tissues is associated with elevation of systemic free fatty acids and insulin resistance in perilipin null mice - Zhai_2010_Horm.Metab.Res_42_247
Author(s) : Zhai W , Xu C , Ling Y , Liu S , Deng J , Qi Y , Londos C , Xu G
Ref : Hormone & Metabolic Research , 42 :247 , 2010
Abstract : Elevated plasma levels of free fatty acids (FFAs) are thought to restrict glucose utilization and induce insulin resistance. Plasma FFA concentrations are primarily governed by lipolysis in adipocytes. Perilipin surrounds the lipid droplet in adipocytes and has a dual role in lipolysis regulation. Perilipin null mice studied by two independent laboratories exhibited similar phenotypes of reduced adipose mass and resistance to diet-induced obesity, but have inconsistent metabolic parameters such as plasma levels of FFA, glucose, and insulin. This discrepancy may be due to differences in genetic background, generation, and nutritional status of the animals examined. In this study, we examined the major metabolic parameters in 129/SvEv perilipin null mice fasted for 4 h and observed increased plasma concentrations of FFA, glycerol, glucose, and insulin. An increase in the score for the homeostasis model assessment of insulin resistance index confirmed the insulin resistance in perilipin null mice, which may be attributed to the plasma FFA elevation. Basal lipolysis was increased in adipose tissues or primary adipocytes isolated from perilipin null mice with increased mass and activity of hormone-sensitive lipase and adipose triglyceride lipase. The increased lipolytic action may accelerate FFA efflux from the adipose tissues to the bloodstream, thereby accounting for systemic FFA elevation and, hence, insulin resistance in perilipin null mice.
ESTHER : Zhai_2010_Horm.Metab.Res_42_247
PubMedSearch : Zhai_2010_Horm.Metab.Res_42_247
PubMedID: 20091459

Title : Cloning and heterologous expression of two cold-active lipases from the Antarctic bacterium Psychrobacter sp. G. - Lin_2010_Polar.Res_29_421
Author(s) : Lin X , Cui S , Xu G , Wang S , Du N
Ref : Polar Research , 29 :421 , 2010
Abstract : Antarctic bacteria producing extracellular lipolytic enzymes with activity at low temperature were isolated, and the most promising strain, named G, was identified as a Psychrobacter species based on 16S rDNA sequence alignment. The genomic DNA of this bacterium was used to construct its plasmid genomic library into pUC118 plasmid vectors, and to screen the cold-active lipolytic enzyme genes. Two genes encoding for cold-active lipolytic enzymes, Lip-1452 (with an open reading frame of 1452 bp in length) and Lip-948 (with an open reading frame of 948 bp in length), were screened. The primary structure of the two lipases deduced from the nucleotide sequence showed a consensus pentapeptide containing the active serine (Lip-1452, GDSAG, and Lip-948, GNSMG) and a conserved His-Gly dipeptide in the N-terminal part of the enzyme. Protein sequence alignment and conserved regions analysis indicated that the two lipases probably belonged to family IV and family V of the bacterial lipolytic enzymes, respectively. The upstream and downstream sequences of the two lipolytic lipases were also obtained. The two lipase genes were cloned into the expression vector pCold III and integrated into Escherichia coli BL21 (DE3). The functional expression of both lipase genes by E. coli BL21 (DE3) cells was observed as the formation of clear haloes around colonies on a 1% (vol/vol) tributyrin plate upon induction with isopropyl-b-Dthiogalactopyranoside at 5C. A lipase activity assay showed that the specific activity of the pCold III+Lip-948 expression system was up to 3.7 U ml-1, whereas that of pCold III+Lip-1452 was very low.
ESTHER : Lin_2010_Polar.Res_29_421
PubMedSearch : Lin_2010_Polar.Res_29_421
PubMedID:
Gene_locus related to this paper: psyck-q1q7w8 , psyck-q1qeu6

Title : Occurrence and degradation characteristics of dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) in typical agricultural soils of China - Xu_2008_Sci.Total.Environ_393_333
Author(s) : Xu G , Li F , Wang Q
Ref : Sci Total Environ , 393 :333 , 2008
Abstract : In this study, we analyze the pollution and degradation characteristics of two kinds of phthalate esters (PEs), dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), in two kinds of soils collected from non-cultivated, crop, greenhouse, and vegetable fields from the Harbin and Handan Districts, China. The results demonstrate that DBP has relatively high residual levels in the soils, ranging from 3.18 to 29.37 mg/kg in fluvo-aquic soils of the Handan District (average 14.06 mg/kg) and 2.75-14.62 mg/kg in black soils of the Harbin District (average 7.60 mg/kg). Residual levels of DEHP reach 1.15-7.99 mg/kg in fluvo-aquic soils of the Handan District (average 4.86 mg/kg) and 0.44-4.20 mg/kg in black soils of the Harbin District (average 2.35 mg/kg). All non-cultivated soils contain the lowest contents of PEs, suggesting that the kinds of pollutants are largely derived from human agricultural activities. Laboratory experiments verify that the degradations of two kinds of PEs are mainly via microbial processes. The microbial populations are higher and reduce more slowly in black soils than those in fluvo-aquic soils. These observations might partially explain the lower levels of residuals and higher degradation rates of PEs pollutants in black soils than those in fluvo-aquic soils. The detection of DBP metabolites indicates that DBP biodegradation might begin by ester hydrolysis to form monobutyl phthalate (MBP) and corresponding alcohol. The MBP then degrades to phthalic acid or butyl benzoate, which might be possibly caused by microbial decarboxylation. The two derivatives of MBP degrade to form protocatechuate through ring cleavage.
ESTHER : Xu_2008_Sci.Total.Environ_393_333
PubMedSearch : Xu_2008_Sci.Total.Environ_393_333
PubMedID: 18258283

Title : Cloning and sequencing of putative acetylcholinesterase cDNAs from the American dog tick, Dermacentor variabilis and the brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae) - Xu_2003_J.Med.Entomol_40_890
Author(s) : Xu G , Fang QQ , Keirans JE , Durden LA
Ref : Journal of Medical Entomology , 40 :890 , 2003
Abstract : wo putative cDNAs of acetylcholinesterase (AChE), one from Dermacentor variabilis, and the other from Rhipicephalus sanguineus, were amplified and sequenced. The deduced amino acid sequences have high amino acid identities (between 70 and 94%) to known tick AChE sequences deposited in GenBank. Furthermore, these two AChEs also possess common features in their primary AChE structure such as catalytic active sites. A 2,220-bp contiguous sequence, containing a 1,791-bp open reading frame encoding an AChE precursor with 596 amino acid residues, was obtained from D. variabilis. The deduced proteins of R. sanguineus are different in size by 6 amino acids because of alternative splicing at the 5' end. A gene tree deduced from phylogenetic analysis indicates that there are at least three lineages of AChE in arthropods.
ESTHER : Xu_2003_J.Med.Entomol_40_890
PubMedSearch : Xu_2003_J.Med.Entomol_40_890
PubMedID: 14765667
Gene_locus related to this paper: derva-ACHE , rhisa-ACHE

Title : Donepezil treatment of vascular dementia - Meyer_2002_Ann.N.Y.Acad.Sci_977_482
Author(s) : Meyer JS , Chowdhury MH , Xu G , Li YS , Quach M
Ref : Annals of the New York Academy of Sciences , 977 :482 , 2002
Abstract : Cholinergic deficits are clinicopathological hallmarks of Alzheimer's disease (DAT) and during the past decade have been the sole target for clinically effective treatments. By contrast, vascular dementia subtypes (VaD) are heterogeneous clinical syndromes, and therapeutic approaches have been directed toward control of vascular risk factors. Little attention has been paid to cholinergic deficits as a mechanism contributing to cognitive impairments in VaD as a potential target for treatment. The purpose of the study was to determine whether there are therapeutic benefits from long-term treatment with cholinesterase inhibitors among VaD patients. Ten VaD patients were diagnosed according to DSM-III-R and NINDS-AIREN criteria and classified into subtypes by neuroimaging. All were treated with titrated doses of donepezil for a mean interval of 15 months. At baseline and follow-up clinic visits, patients underwent medical and neurological examinations, as well as neuropsychological testing including Mini-Mental Status Examinations (MMSE) and Cognitive Capacity Screening Examinations (CCSE). Cognitive statuses of 10 treated patients were then compared before and after treatment. Net changes were expressed as annual MMSE score changes (DeltaMMSE/year) and annual CCSE score changes (DeltaCCSE/year). Of the 10 treated VaD patients, cognitive improvements were found when comparisons were made before and after treatment. Ten treated patients also showed greater cognitive improvements, while untreated patients showed continued cognitive decline. This study suggests that cholinergic deficits in VaD are due to neuronal ischemic damage with loss of acetylcholine and that treatment of VaD with cholinesterase inhibitors is a rational therapy.
ESTHER : Meyer_2002_Ann.N.Y.Acad.Sci_977_482
PubMedSearch : Meyer_2002_Ann.N.Y.Acad.Sci_977_482
PubMedID: 12480789

Title : Human carboxylesterase 2 is commonly expressed in tumor tissue and is correlated with activation of irinotecan - Xu_2002_Clin.Cancer.Res_8_2605
Author(s) : Xu G , Zhang W , Ma MK , McLeod HL
Ref : Clin Cancer Research , 8 :2605 , 2002
Abstract : The prodrug irinotecan is an active agent for the treatment of advanced colorectal cancer and a number of other solid tumors. Irinotecan is converted in vivo to SN-38 (7-ethyl-10-hydroxy-camptothecin), the active metabolite that causes cell death, by human liver carboxylesterases. Previous studies suggest that human carboxylesterase 2 (CES2) is the key activating isoform. Although conversion of irinotecan to SN-38 by liver carboxylesterase is an inefficient process, clinical data indicate that irinotecan has significant antitumor activity. This scenario raises the possibility that local conversion of irinotecan to SN-38 by CES2 in tumor tissues might occur. The expression profile of CES2 protein in human tumor tissues was evaluated in a tissue array of 18 different types of human cancer and in a panel of normal human liver samples by immunohistochemistry and Western blot, respectively. Cytosolic CES2 expression was observed in 101 of 154 tumors (66%) and 55 of 60 normal tissues (92%). Among the 18 types of tumors analyzed, 2 types (gallbladder tumor and lymphoma) did not express CES2, 5 types expressed weak CES2, and 11 types expressed moderate to intense CES2. In functional studies, CES2 protein was highly variable among liver samples, with a 15-fold range in cytosol and a 3-fold range in microsome fractions. Liver microsomal CES2 protein expression was significantly correlated with irinotecan activation to SN-38 (R(s) = 0.70; P = 0.007). This study confirms that CES2 is a key enzyme for irinotecan activation. Tumor CES2 expression may contribute to variable response to irinotecan chemotherapy for solid tumors.
ESTHER : Xu_2002_Clin.Cancer.Res_8_2605
PubMedSearch : Xu_2002_Clin.Cancer.Res_8_2605
PubMedID: 12171891

Title : Feasibility of treating mild cognitive impairment with cholinesterase inhibitors -
Author(s) : Meyer JS , Li Y , Xu G , Thornby J , Chowdhury M , Quach M
Ref : Int J Geriatr Psychiatry , 17 :586 , 2002
PubMedID: 12112184

Title : Complete DNA sequence of yeast chromosome XI - Dujon_1994_Nature_369_371
Author(s) : Dujon B , Alexandraki D , Andre B , Ansorge W , Baladron V , Ballesta JP , Banrevi A , Bolle PA , Bolotin-Fukuhara M , Bossier P , Bou G , Boyer J , Bultrago MJ , Cheret G , Colleaux L , Dalgnan-Fornler B , del Rey F , Dlon C , Domdey H , Dsterhoft A , Dsterhus S , Entlan KD , Erfle H , Esteban PF , Feldmann H , Fernandes L , Robo GM , Fritz C , Fukuhara H , Gabel C , Gaillon L , Carcia-Cantalejo JM , Garcia-Ramirez JJ , Gent NE , Ghazvini M , Goffeau A , Gonzalez A , Grothues D , Guerreiro P , Hegemann J , Hewitt N , Hilger F , Hollenberg CP , Horaitis O , Indge KJ , Jacquier A , James CM , Jauniaux C , Jimenez A , Keuchel H , Kirchrath L , Kleine K , Ktter P , Legrain P , Liebl S , Louis EJ , Maia e Silva A , Marck C , Monnier AL , Mostl D , Mller S , Obermaier B , Oliver SG , Pallier C , Pascolo S , Pfeiffer F , Philippsen P , Planta RJ , Pohl FM , Pohl TM , Pohlmann R , Portetelle D , Purnelle B , Puzos V , Ramezani Rad M , Rasmussen SW , Remacha M , Revuelta JL , Richard GF , Rieger M , Rodrigues-Pousada C , Rose M , Rupp T , Santos MA , Schwager C , Sensen C , Skala J , Soares H , Sor F , Stegemann J , Tettelin H , Thierry A , Tzermia M , Urrestarazu LA , van Dyck L , Van Vliet-Reedijk JC , Valens M , Vandenbo M , Vilela C , Vissers S , von Wettstein D , Voss H , Wiemann S , Xu G , Zimmermann J , Haasemann M , Becker I , Mewes HW
Ref : Nature , 369 :371 , 1994
Abstract : The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome XI has been determined. In addition to a compact arrangement of potential protein coding sequences, the 666,448-base-pair sequence has revealed general chromosome patterns; in particular, alternating regional variations in average base composition correlate with variations in local gene density along the chromosome. Significant discrepancies with the previously published genetic map demonstrate the need for using independent physical mapping criteria.
ESTHER : Dujon_1994_Nature_369_371
PubMedSearch : Dujon_1994_Nature_369_371
PubMedID: 8196765
Gene_locus related to this paper: yeast-mgll