Topic
Esterase
About: Esterase is a research topic. Over the lifetime, 7622 publications have been published within this topic receiving 168270 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: Comparison of the amino acid sequence of this enzyme allows us to propose that Ser165, Asp262 and His292 constitute the catalytic triad of E. coli esterase, suggesting that the enzyme exists in a monomeric form.
Abstract: An esterase from Escherichia coli that is a member of the hormone-sensitive lipase (HSL) family was overproduced, purified and characterized. It is encoded by the ybaC gene and composed of 319 amino acid residues with an Mr of 36038. The enzymic activity was determined by using various p-nitrophenyl esters of fatty acids as a substrate at 25 degreesC and pH 7.1. The enzyme showed hydrolytic activity towards substrates with an acyl chain length of less than 8, whereas it showed little hydrolytic activity towards those with an acyl chain length of more than 10. In addition, it showed little hydrolytic activity towards trioleoylglycerol and cholesterol oleate. Determination of the kinetic parameters for the hydrolyses of the substrates from C2 to C8 indicates that C4 and C5 substrates are the most preferred. Close agreement between the Mr determined by SDS/PAGE (37000) and column chromatography (38000) suggests that the enzyme exists in a monomeric form. It is an acidic protein with a pI value of 4.1. The far-UV CD spectrum suggests that its helical content is 26.1%. Comparison of the amino acid sequence of this enzyme with those involved in the HSL family allows us to propose that Ser165, Asp262 and His292 constitute the catalytic triad of E. coli esterase.
70 citations
TL;DR: In this paper, a structural genomic approach was used to identify the Rv1399c gene product, LipH, previously annotated as a putative lipase, as a nonlipolytic rather than a lipolytic hydrolase.
Abstract: The Mycobacterium tuberculosis genome contains an unusually high number of proteins involved in the metabolism of lipids belonging to the Lip family, including various nonlipolytic and lipolytic hydrolases. Driven by a structural genomic approach, we have biochemically characterized the Rv1399c gene product, LipH, previously annotated as a putative lipase. Rv1399c was overexpressed in E. coli as inclusion bodies and refolded. Rv1399c efficiently hydrolyzes soluble triacylglycerols and vinyl esters. It is inactive against emulsified substrate and its catalytic activity is strongly inhibited by the diethyl paranitrophenyl phosphate (E600). These kinetic behaviors unambiguously classify Rv1399c as a nonlipolytic rather than a lipolytic hydrolase. Sequence alignment reveals that this enzyme belongs to the alpha/beta hydrolase fold family and shares 30-40% amino acid sequence identity with members of the hormone-sensitive lipase subfamily. A model of Rv1399c derived from homologous three-dimensional structures reveals a canonical catalytic triad (Ser162, His290 and Asp260) located at the bottom of a solvent accessible pocket lined by neutral or charged residues. Based on this model, kinetic data of the Arg213Ala mutant partially explain the role of the guanidinium moiety, located close to His290, to confer an unusual low pH shift of the catalytic histidine in the wild type enzyme. Overall, these data identify Rv1399c as a new nonlipolytic hydrolase from M. tuberculosis and we thus propose to reannotate its gene product as NLH-H.
70 citations
TL;DR: By comparing esterase zymograms from different tissues and from different species, it is apparent that the distribution and multiplicity of ester enzyme activity is tissue and species specific.
70 citations
TL;DR: EstS1, a newly identified thermostable esterase from Sulfobacillus acidophilus DSM10332, was heterologously expressed in Escherichia coli and shown to enzymatically degrade phthalate esters to their corresponding monoalkyl PAEs.
Abstract: EstS1, a newly identified thermostable esterase from Sulfobacillus acidophilus DSM10332, was heterologously expressed in Escherichia coli and shown to enzymatically degrade phthalate esters (PAEs) to their corresponding monoalkyl PAEs. The optimal pH and temperature of the esterase were found to be 8.0 and 70°C, respectively. The half-life of EstS1 at 60°C was 15 h, indicating that the enzyme had good thermostability. The specificity constant (kcat/Km) of the enzyme for p-nitrophenyl butyrate was as high as 6,770 mM(-1) s(-1). The potential value of EstS1 was demonstrated by its ability to effectively hydrolyze 35 to 82% of PAEs (10 mM) within 2 min at 37°C, with all substrates being completely degraded within 24 h. At 60°C, the time required for complete hydrolysis of most PAEs was reduced by half. To our knowledge, this enzyme is a new esterase identified from thermophiles that is able to degrade various PAEs at high temperatures.
70 citations
TL;DR: The structure of PFE, an aryl esterase from Pseudomonas fluorescens, has been solved to a resolution of 1.8 A by X-ray diffraction and shows a characteristic alpha/beta-hydrolase fold and shows its preference for small acyl groups.
Abstract: The structure of PFE, an aryl esterase from Pseudomonas fluorescens, has been solved to a resolution of 1.8 A by X-ray diffraction and shows a characteristic α/β-hydrolase fold. In addition to catalyzing the hydrolysis of esters in vitro, PFE also shows low bromoperoxidase activity. PFE shows highest structural similarity, including the active-site environment, to a family of non-heme bacterial haloperoxidases, with an r.m.s. deviation in 271 Cα atoms between PFE and its five closest structural neighbors averaging 0.8 A. PFE has far less similarity (r.m.s. deviation in 218 Cα atoms of 5.0 A) to P. fluorescens carboxyl esterase. PFE favors activated esters with small acyl groups, such as phenyl acetate. The X-ray structure of PFE reveals a significantly occluded active site. In addition, several residues, including Trp28 and Met95, limit the size of the acyl-binding pocket, explaining its preference for small acyl groups.
70 citations