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Esterase

About: Esterase is a research topic. Over the lifetime, 7622 publications have been published within this topic receiving 168270 citations.


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Journal ArticleDOI
TL;DR: Heterologous expression in Aspergillus vadensis, Pycnoporus cinnabarinus and Schizophyllum commune resulted in extracellular glucuronoyl esterase activity, demonstrating that these genes encode this enzymatic function.
Abstract: The white-rot fungus Phanerochaete chrysosporium produces glucuronoyl esterase, a recently discovered carbohydrate esterase, during growth on sugar beet pulp. Two putative genes encoding this enzyme, ge1 and ge2, were isolated and cloned. Heterologous expression in Aspergillus vadensis, Pycnoporus cinnabarinus and Schizophyllum commune resulted in extracellular glucuronoyl esterase activity, demonstrating that these genes encode this enzymatic function. The amino acid sequence of GE1 was used to identify homologous genes in the genomes of twenty-four fungi. Approximately half of the genomes, both from ascomycetes and basidiomycetes, contained putative orthologues, but their presence could not be assigned to any of fungal class or subclass. Comparison of the amino acid sequences of identified and putative glucuronoyl esterases to other types of carbohydrate esterases (CE) confirmed that they form a separate family of CEs. These enzymes are interesting candidates for biotechnological applications such as the separation of lignin and hemicellulose.

52 citations

Journal Article
TL;DR: The lack of straight forward correlation between cocaine methyl esterase activity and immunoreactive protein and nonspecific ester enzyme activity suggests that more than one enzyme catalyzes the hydrolysis of cocaine to benzoylecgonine in the rat.
Abstract: The tissue distribution of cocaine methyl esterase and ethanol-dependent ethyl transferase activities was determined in the rat and compared to the tissue distribution of three distinct non-specific hydrolases. Rates of formation of benzoylecgonine from cocaine and cocaethylene from ethanol and cocaine were measured in serum and tissue homogenate-supernatants of the brain, heart, kidney, liver, lung and spleen. The tissue distribution of three nonspecific esterases, A, B and C, was defined by nondenaturing gel electrophoresis and measuring the hydrolysis of 4-methylumbelliferyl acetate in the gels. Immunoreactive protein was localized by using Western blot analysis with polyclonal rabbit antihuman liver cocaine methyl esterase antibody after denaturing and nondenaturing gel electrophoresis. The rat liver, lung, kidney and heart exhibited cocaine methyl esterase and ethyl transferase activities and immunoreactive protein. The brain had cocaine methyl esterase activity but no ethyl transferase activity; neither activity was found in serum or spleen. The dominant immunoreactive bands in the liver, lung, kidney and heart comigrated with the 59 kD band of purified human liver cocaine methyl esterase. The rat liver, lung and kidney exhibited a band of nonspecific esterase activity that migrated with purified human liver cocaine methyl esterase and rat hydrolase A. These observations suggest that rat hydrolase A is similar to human cocaine methyl esterase. The lack of straight forward correlation between cocaine methyl esterase activity and immunoreactive protein and nonspecific esterase activity suggests that more than one enzyme catalyzes the hydrolysis of cocaine to benzoylecgonine in the rat.

52 citations

Journal ArticleDOI
TL;DR: The [ 18 O 2 ]PGF2α was found to be relative stable toward back exchange in methanol, aqueous buffer, and urine, but rapidly back exchanged to the native PGF2α in plasma with a half-life of 1 h.

52 citations

Journal ArticleDOI
Y.-J. Choi1, B. H. Lee1
TL;DR: Culture conditions in growth and esterase production by a newly isolated Lactobacillus casei CL96 were investigated and the enzyme activity was maximal at pH 7.0 and 37°C, which might be suitable for biotechnological applications in the dairy industry.
Abstract: Culture conditions in growth and esterase production by a newly isolated Lactobacillus casei CL96 were investigated using a dextrose-free MRS medium supplemented with different sugars in a 2 l fermentor at different pHs (4.0–9.0) and temperatures (20–50°C). The optimal growth was obtained in basal MRS medium containing 1% (w/v) lactose at pH 7.0 and 30°C. The maximal esterase production was obtained intracellularly during the late logarithmic phase, but during the stationary phase, the esterase activity was released in the culture medium. The enzyme activity was maximal at pH 7.0 and 37°C. Among various substrates (C2–C16) tested, the highest activity was towards C6 and C8. Though the enzyme was produced constitutively, the tributylin induced the enzyme production by 2.5 fold. L. casei CL96 esterase was very active at neutral pH and ambient temperature and might be suitable for biotechnological applications in the dairy industry.

52 citations

Journal ArticleDOI
TL;DR: Carboxylic ester hydrolases in human serum were identified, characterized, and quantified by means of crossed and rocket immunoelectrophoresis, illustrating general methodological problems concerning immunochemical characterization of enzymes.
Abstract: Carboxylic ester hydrolases in human serum were identified, characterized, and quantified by means of crossed and rocket immunoelectrophoresis. Two types of esterase were found, arylesterase (EC 3.1.1.2) and cholinesterase (EC 3.1.1.8), exhibiting differences in specificity for several histochemical substrates. α-naphthyl acetate and β-naphthyl acetate were used to distinguish between the two enzymes. Arylesterase seemed to interact specifically with aJipoprotein. Quantitation of enzyme protein and correlation with enzyme activity is described. The experiments illustrate general methodological problems concerning immunochemical characterization of enzymes.

52 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202391
2022209
202183
2020112
2019107
2018129