scispace - formally typeset
Search or ask a question
Topic

Esterase

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


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, depot ester derivatives of the nucleoside ara-cytidine (cytarabine, Cytosar) were used for clinical trial in cancer and rheumatoid arthritis.
Abstract: This manuscript if one of a series of investigations into modifying the pharmacologic properties of the antitumor, antiviral, and immunosuppressive nucleoside ara-cytidine (cytarabine, Cytosar). The present paper summarizes our studies on depot ester derivatives of the nucleoside. We are able to predict with reasonable accuracy the biological activity as measured by increased life span in the L1210 leukemic mouse from a combination of two predictor variables: (1) the solubility of the ester in water and (2) its rate of hydrolysis by the mixed esterase system of animal plasma. We have tried unsuccessfully to correlate enzymatic hydrolysis rates with an alkaline hydrolysis model. Calculated Hansch partition (p) values had a correlation of r equal to 0.86 with water solubility. These p values had no additional predictive value. Based on our results, two esters were selected for clinical trial in cancer and rheumatoid arthritis.

49 citations

Journal ArticleDOI
TL;DR: Flow cytometry was used with different viability dyes to assess changes in cell structure and function induced by acetic acid (AA) in populations of Zygosaccharomyces bailii and SacCharomyces cerevisiae, and to detect changes in esterase activity, intracellular dye processing, and membrane integrity.
Abstract: Flow cytometry (FCM) was used with different viability dyes to assess changes in cell structure and function induced by acetic acid (AA) in populations of Zygosaccharomyces bailii (AA resistant) and Saccharomyces cerevisiae (AA sensitive). Kinetic changes in esterase activity, intracellular dye processing, and membrane integrity were monitored, and to detect those changes we used three assays involving fluorescein diacetate hydrolysis, FUN-1 processing, and propidium iodide exclusion, respectively. In S. cerevisiae, the decrease in the ability to process FUN-1 preceded the decrease in esterase activity, and there was loss of cell membrane integrity after incubation with AA. In Z. bailii, with higher AA concentrations, there was a similar decrease in the ability to process FUN-1, which also preceded the loss of cell membrane integrity. Changes in esterase activity in this yeast induced by AA treatment could not be monitored because the changes occurred independently of the presence of the acid. For control samples (untreated cells killed with 10% v/v of AA), the percentages of nonaltered cells as estimated by FCM and percentages of viable cells as estimated by colony forming unit (CFU) counts were identical. However, for cell samples treated for short periods with 3% (v/v) or less of AA, none of the dyes produced FCM results comparable to those produced by CFU counts.

49 citations

Journal ArticleDOI
TL;DR: For the majority of the strains, the absence of correlation between zymotype, ribotype and serotype argues for a high level of heterogeneity within P. aeruginosa and indicates that the parallel use of the first two methods represent a potential tool for epidemiological study.
Abstract: Summary The intra-species differentiation of Pseudomonas aeruginosa was analysed by comparing the polymorphism of esterases by conventional polyacrylamide-agarose gel electrophoresis, the physicochemical properties of the variants of the major esterase P3 and the restriction fragment length polymorphism of ribosomal RNA gene regions (ribotyping) to O-serotyping for several panels of strains selected from among a series of 257 clinical isolates and two references strains, (ATCC nos. 10145 and 27853). The electrophoretic variation of four main kinds of esterase (P1-P4) and 11 additional esterases distinguished by their spectra of hydrolytic activity with synthetic substrates and by their sensitivity to di-isopropyl-fluorophosphate, allowed the discrimination of 67 zymotypes. Thirty-two esterase P3 variants were characterised by their pI, electrophoretic mobilities and titration curve analyses. They were distributed into two groups which, by these molecular criteria, seem to be distantly related. Combination of the patterns resulting from HindIII, EcoRI and BclI. restriction endonuclease digestions allowed the discrimination of 33 ribotypes among 134 strains. The strains exhibiting esterase P3 variants of group 2 presented a distinct ribotype and belonged to serotype O12. They could constitute a distinct group within the species. For the majority of the strains, the absence of correlation between zymotype, ribotype and serotype argues for a high level of heterogeneity within P. aeruginosa and indicates that the parallel use of the first two methods represent a potential tool for epidemiological study.

49 citations

Journal ArticleDOI
TL;DR: This work represents the first example of the purification and identification of a thermophilic glucuronoyl esterase from S. thermophile and was proved to be a modular enzyme containing a noncatalytic carbohydrate-binding module.
Abstract: The cellulolytic system of the thermophilic fungus Sporotrichum thermophile contains a recently discovered esterase that may hydrolyze the ester linkage between the 4-O-methyl-D-glucuronic acid of glucuronoxylan and lignin alcohols. The glucuronoyl esterase named StGE1 was purified to homogeneity with a molecular mass of M(r) 58 kDa and pI 6.7. The enzyme activity was optimal at pH 6.0 and 60 degrees C. The esterase displayed a narrow pH range stability at pH 8.0 and retained 50% of its activity after 430 and 286 min at 50 and 55 degrees C, respectively. The enzyme was active on substrates containing glucuronic acid methyl ester, showing a lower catalytic efficiency on 4-nitrophenyl 2-O-(methyl-4-O-methyl-alpha-d-glucopyranosyluronate)-beta-D-xylopyranoside than its mesophilic counterparts reported in the literature, which is typical of thermophilic enzymes. StGE1 was proved to be a modular enzyme containing a noncatalytic carbohydrate-binding module. LC-MS/MS analysis provided peptide mass and sequence information that facilitated the identification and classification of StGE1 as a family 15 glucuronoyl esterase that showed the highest homology with the hypothetical glucuronoyl esterase CHGG_10774 of Chaetomium globosum CBS 148.51. This work represents the first example of the purification and identification of a thermophilic glucuronoyl esterase from S. thermophile.

49 citations


Network Information
Related Topics (5)
Enzyme
32.8K papers, 1.1M citations
90% related
Amino acid
124.9K papers, 4M citations
86% related
Peptide sequence
84.1K papers, 4.3M citations
82% related
Glutathione
42.5K papers, 1.8M citations
82% related
Protein subunit
33.2K papers, 1.7M citations
81% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202391
2022209
202183
2020112
2019107
2018129