Tran H

References (7)

Title : The Mobility of the Cap Domain Is Essential for the Substrate Promiscuity of a Family IV Esterase from Sorghum Rhizosphere Microbiome - Distaso_2023_Appl.Environ.Microbiol__e0180722
Author(s) : Distaso M , Cea-Rama I , Coscolin C , Chernikova TN , Tran H , Ferrer M , Sanz-Aparicio J , Golyshin PN
Ref : Applied Environmental Microbiology , :e0180722 , 2023
Abstract : Metagenomics offers the possibility to screen for versatile biocatalysts. In this study, the microbial community of the Sorghum bicolor rhizosphere was spiked with technical cashew nut shell liquid, and after incubation, the environmental DNA (eDNA) was extracted and subsequently used to build a metagenomic library. We report the biochemical features and crystal structure of a novel esterase from the family IV, EH(0), retrieved from an uncultured sphingomonad after a functional screen in tributyrin agar plates. EH(0) (optimum temperature [T(opt)], 50 degreesC; melting temperature [T(m)], 55.7 degreesC; optimum pH [pH(opt)], 9.5) was stable in the presence of 10 to 20% (vol/vol) organic solvents and exhibited hydrolytic activity against p-nitrophenyl esters from acetate to palmitate, preferably butyrate (496 U mg(-1)), and a large battery of 69 structurally different esters (up to 30.2 U mg(-1)), including bis(2-hydroxyethyl)-terephthalate (0.16 +/- 0.06 U mg(-1)). This broad substrate specificity contrasts with the fact that EH(0) showed a long and narrow catalytic tunnel, whose access appears to be hindered by a tight folding of its cap domain. We propose that this cap domain is a highly flexible structure whose opening is mediated by unique structural elements, one of which is the presence of two contiguous proline residues likely acting as possible hinges, which together allow for the entrance of the substrates. Therefore, this work provides a new role for the cap domain, which until now was thought to be an immobile element that contained hydrophobic patches involved in substrate prerecognition and in turn substrate specificity within family IV esterases. IMPORTANCE A better understanding of structure-function relationships of enzymes allows revelation of key structural motifs or elements. Here, we studied the structural basis of the substrate promiscuity of EH(0), a family IV esterase, isolated from a sample of the Sorghum bicolor rhizosphere microbiome exposed to technical cashew nut shell liquid. The analysis of EH(0) revealed the potential of the sorghum rhizosphere microbiome as a source of enzymes with interesting properties, such as pH and solvent tolerance and remarkably broad substrate promiscuity. Its structure resembled those of homologous proteins from mesophilic Parvibaculum and Erythrobacter spp. and hyperthermophilic Pyrobaculum and Sulfolobus spp. and had a very narrow, single-entry access tunnel to the active site, with access controlled by a capping domain that includes a number of nonconserved proline residues. These structural markers, distinct from those of other substrate-promiscuous esterases, can help in tuning substrate profiles beyond tunnel and active site engineering.
ESTHER : Distaso_2023_Appl.Environ.Microbiol__e0180722
PubMedSearch : Distaso_2023_Appl.Environ.Microbiol__e0180722
PubMedID: 36602332
Gene_locus related to this paper: 9bact-EH0

Title : The environment shapes microbial enzymes: five cold-active and salt-resistant carboxylesterases from marine metagenomes - Tchigvintsev_2015_Appl.Microbiol.Biotechnol_99_2165
Author(s) : Tchigvintsev A , Tran H , Popovic A , Kovacic F , Brown G , Flick R , Hajighasemi M , Egorova O , Somody JC , Tchigvintsev D , Khusnutdinova A , Chernikova TN , Golyshina OV , Yakimov MM , Savchenko A , Golyshin PN , Jaeger KE , Yakunin AF
Ref : Applied Microbiology & Biotechnology , 99 :2165 , 2015
Abstract : Most of the Earth's biosphere is cold and is populated by cold-adapted microorganisms. To explore the natural enzyme diversity of these environments and identify new carboxylesterases, we have screened three marine metagenome gene libraries for esterase activity. The screens identified 23 unique active clones, from which five highly active esterases were selected for biochemical characterization. The purified metagenomic esterases exhibited high activity against alpha-naphthyl and p-nitrophenyl esters with different chain lengths. All five esterases retained high activity at 5 degrees C indicating that they are cold-adapted enzymes. The activity of MGS0010 increased more than two times in the presence of up to 3.5 M NaCl or KCl, whereas the other four metagenomic esterases were inhibited to various degrees by these salts. The purified enzymes showed different sensitivities to inhibition by solvents and detergents, and the activities of MGS0010, MGS0105 and MGS0109 were stimulated three to five times by the addition of glycerol. Screening of purified esterases against 89 monoester substrates revealed broad substrate profiles with a preference for different esters. The metagenomic esterases also hydrolyzed several polyester substrates including polylactic acid suggesting that they can be used for polyester depolymerization. Thus, esterases from marine metagenomes are cold-adapted enzymes exhibiting broad biochemical diversity reflecting the environmental conditions where they evolved.
ESTHER : Tchigvintsev_2015_Appl.Microbiol.Biotechnol_99_2165
PubMedSearch : Tchigvintsev_2015_Appl.Microbiol.Biotechnol_99_2165
PubMedID: 25194841

Title : Hands-On Approach to Structure Activity Relationships: The Synthesis, Testing, and Hansch Analysis of a Series of Acetylcholineesterase Inhibitors - ocock_2015_J.Chem.Educ_92_1745
Author(s) : Locock K , Tran H , Codd R , Allan R
Ref : Journal of Chemical Education , 92 :1745 , 2015
Abstract :
ESTHER : ocock_2015_J.Chem.Educ_92_1745
PubMedSearch : ocock_2015_J.Chem.Educ_92_1745
PubMedID:

Title : Genome sequence and functional genomic analysis of the oil-degrading bacterium Oleispira antarctica - Kube_2013_Nat.Commun_4_2156
Author(s) : Kube M , Chernikova TN , Al-Ramahi Y , Beloqui A , Lopez-Cortez N , Guazzaroni ME , Heipieper HJ , Klages S , Kotsyurbenko OR , Langer I , Nechitaylo TY , Lunsdorf H , Fernandez M , Juarez S , Ciordia S , Singer A , Kagan O , Egorova O , Petit PA , Stogios P , Kim Y , Tchigvintsev A , Flick R , Denaro R , Genovese M , Albar JP , Reva ON , Martinez-Gomariz M , Tran H , Ferrer M , Savchenko A , Yakunin AF , Yakimov MM , Golyshina OV , Reinhardt R , Golyshin PN
Ref : Nat Commun , 4 :2156 , 2013
Abstract : Ubiquitous bacteria from the genus Oleispira drive oil degradation in the largest environment on Earth, the cold and deep sea. Here we report the genome sequence of Oleispira antarctica and show that compared with Alcanivorax borkumensis--the paradigm of mesophilic hydrocarbonoclastic bacteria--O. antarctica has a larger genome that has witnessed massive gene-transfer events. We identify an array of alkane monooxygenases, osmoprotectants, siderophores and micronutrient-scavenging pathways. We also show that at low temperatures, the main protein-folding machine Cpn60 functions as a single heptameric barrel that uses larger proteins as substrates compared with the classical double-barrel structure observed at higher temperatures. With 11 protein crystal structures, we further report the largest set of structures from one psychrotolerant organism. The most common structural feature is an increased content of surface-exposed negatively charged residues compared to their mesophilic counterparts. Our findings are relevant in the context of microbial cold-adaptation mechanisms and the development of strategies for oil-spill mitigation in cold environments.
ESTHER : Kube_2013_Nat.Commun_4_2156
PubMedSearch : Kube_2013_Nat.Commun_4_2156
PubMedID: 23877221
Gene_locus related to this paper: olean-olei00960 , olean-r4ym14 , olean-r4yv64 , olean-r4ys13

Title : Genome Sequence of Thalassolituus oleivorans MIL-1 (DSM 14913T) - Golyshin_2013_Genome.Announc_1_e0014113
Author(s) : Golyshin PN , Werner J , Chernikova TN , Tran H , Ferrer M , Yakimov MM , Teeling H , Golyshina OV
Ref : Genome Announc , 1 :e0014113 , 2013
Abstract : Thalassolituus oleivorans is one of the most prevalent marine gammaproteobacteria in microbial communities, emerging after oil spills in coastal, estuarine, and surface seawaters. Here, we present the assembled genome of strain T. oleivorans MIL-1 (DSM 14913(T)), which is 3,920,328 bp with a G+C content of 46.6%.
ESTHER : Golyshin_2013_Genome.Announc_1_e0014113
PubMedSearch : Golyshin_2013_Genome.Announc_1_e0014113
PubMedID: 23599290
Gene_locus related to this paper: 9gamm-m5dq85 , 9gamm-m5dt68 , 9gamm-m5dm97

Title : Refsum's Disease-Use of the Intestinal Lipase Inhibitor, Orlistat, as a Novel Therapeutic Approach to a Complex Disorder - Perera_2011_J.Obes_2011_
Author(s) : Perera NJ , Lewis B , Tran H , Fietz M , Sullivan DR
Ref : J Obes , 2011 : , 2011
Abstract : Refsum's Disease is an inherited metabolic disorder in which a metabolite of branched chain fatty acids accumulates due to lack of appropriate oxidative enzymes. Patients have elevated plasma phytanic acid levels and high concentrations of phytanic acid in a variety of tissues leading to progressive tissue damage. Besides retinal degeneration or retinal dystrophy associated with adult onset retinitis pigmentosa, additional symptoms include chronic polyneuropathy, cerebellar ataxia, sensorineural hearing loss, anosmia, ichthyosis, as well as skeletal, cardiac, hepatic, and renal abnormalities. Current management includes avoidance of dietary sources of branched chain fatty acids and regular plasmapheresis to prevent accumulation of these compounds to ameliorate progressive neurological deficits. Two brothers with Refsum's disease who experienced progressive symptoms despite optimal diet and plasmapheresis were commenced on a novel therapy. We report the effect of the intestinal lipase inhibitor, Orlistat, which led to significant reduction (P-value <0.001 on 2-sample unpaired t-test) of mean preplasmapheresis phytanic acid levels with retardation of the progression of most of their dermatological and neurological symptoms.
ESTHER : Perera_2011_J.Obes_2011_
PubMedSearch : Perera_2011_J.Obes_2011_
PubMedID: 20871815

Title : Identification of the 170-kDa melanoma membrane-bound gelatinase (seprase) as a serine integral membrane protease - Pineiro-Sanchez_1997_J.Biol.Chem_272_7595
Author(s) : Pineiro-Sanchez ML , Goldstein LA , Dodt J , Howard L , Yeh Y , Tran H , Argraves WS , Chen WT
Ref : Journal of Biological Chemistry , 272 :7595 , 1997
Abstract : The 170-kDa membrane-bound gelatinase, seprase, is a cell surface protease, the expression of which correlates with the invasive phenotype of human melanoma and carcinoma cells. We have isolated seprase from cell membranes and shed vesicles of LOX human melanoma cells. The active enzyme is a dimer of N-glycosylated 97-kDa subunits. Sequence analysis of three internal proteolytic fragments of the 97-kDa polypeptide revealed up to 87.5% identity to the 95-kDa fibroblast activation protein alpha (FAPalpha), the function of which is unknown. Thus, we used reverse transcription-polymerase chain reaction to generate a 2.4-kilobase cDNA from LOX mRNA with FAPalpha primers. COS-7 cells transfected with this cDNA expressed a 170-kDa gelatinase that is recognized by monoclonal antibodies directed against seprase. Sequence analysis also showed similarities to the 110-kDa subunit of dipeptidyl peptidase IV (DPPIV). Like DPPIV, the gelatinase activity of seprase was completely blocked by serine-protease inhibitors, including diisopropyl fluorophosphate. Seprase could be affinity-labeled by [3H]diisopropyl fluorophosphate, but the proteolytically inactive 97-kDa subunit could not, confirming the existence of a serine protease active site on the dimeric form. Proteolytic activity is lost upon dissociation into its 97-kDa subunit following treatment with acid, heat, or cysteine and histidine-modifying agents. We conclude that seprase, FAPalpha, and DPPIV are related serine integral membrane proteases and that seprase is similar to DPPIV, the proteolytic activities of which are dependent upon subunit association.
ESTHER : Pineiro-Sanchez_1997_J.Biol.Chem_272_7595
PubMedSearch : Pineiro-Sanchez_1997_J.Biol.Chem_272_7595
PubMedID: 9065413
Gene_locus related to this paper: human-FAP