Topic
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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TL;DR: The estcrolytic and lipolytic enzymes were produced by cell lysis of Lactobacillus casei-subsp-casei LLG during the late logarithmic growth phase and purified to 67 fold by ion exchange chromatography and gel filtration chromatography using the FPLC system.
Abstract: The estcrolytic and lipolytic enzymes were produced by cell lysis of Lactobacillus casei-subsp-casei LLG during the late logarithmic growth phase. The enzyme was purified to 67 fold by ion exchange chromatography and gel filtration chromatography using the FPLC system. Polyacrylamide gel electrophoresis and sodium dodecyl sulfate-poly-acrylamide gel electrophoresis using the “Phast” system of the purified enzyme showed a single protein band for butyrate-esterase (3.2 × 105 Dalton), caproate esterase (1.1 × 105 Dalton) and capryate esterase (4.0 × 104 Dalton), respectively. The maximum lipolytic activity was observed at pH 7.2 and 37°C. The enzyme activity was inhibited by silver and mercury ions but magnesium and calcium stimulated lipolytic activity. The Km and Vmax values for esterase-lipase of the strain LLG were 76 μM/min/mg of protein, and 0.57 mM, respectively. This enzyme was stable at room temperature for at least 2 days.
58 citations
TL;DR: It is suggested that the two electrophoretically identical B1 esterase isoenzymes from California and Cuba have been amplified independently, if amplification has occurred only once, and the original amplification has not occurred recently.
Abstract: Resistance to organophosphates in Culex mosquitoes is typically associated with increased activity of non-specific esterases. The commonest phenotype involves two elevated esterases, A2 and B2, while some strains have elevation of esterase B1 alone. Overexpression of the two B esterase electromorphs is due to gene amplification. Full-length cDNAs coding for amplified esterase B genes from a resistant Cuban strain (MRES, with amplified B1 esterase) and a Sri Lankan strain (PelRR, with amplified B2 esterase) of C. quinquefasciatus have been sequenced. In addition, a partial-length cDNA coding for a B esterase from an insecticide-susceptible Sri Lankan strain (PelSS) has been sequenced. All the nucleotide sequences and the inferred amino acid sequences show a high level of identify (> 95% at the nucleotide and amino acid level), confirming that they are an allelic series. The two B1 esterase nucleotide sequences (MRES and the previously published TEM-R [Mouches, Pauplin, Agarwal, Lemieux, Herzog, Abadon, Beyssat-Arnaouty, Hyrien, De Saint Vincent, Georghiou and Pasteur (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 2574-2578]) showed the lowest identity, and restriction-fragment-length-polymorphism analysis of the two strains was different. On the basis of these data we suggest that the two electrophoretically identical B1 esterase isoenzymes from California and Cuba have been amplified independently. Alternatively, if amplification has occurred only once, the original amplification has not occurred recently.
58 citations
TL;DR: Results indicate that intestinal esterase from humans differs characteristically from esterases in experimental animals, and appears to be characteristically quite different from hepatic esters.
58 citations
TL;DR: Forty-five potato varieties were analysed for three biochemical systems obtained from tuber extracts, finding this is an effective and efficient procedure for variety identification.
Abstract: Forty-five potato varieties were analysed for three biochemical systems obtained from tuber extracts. The systems employed were esterase and peroxidase isozymes and soluble-proteins patterns; separation was accomplished by disc electrophoresis. Five esterase isozymes, a group of eight peroxidase isozymes and more than 20 proteins were present in unique combinations specific for each variety. This is an effective and efficient procedure for variety identification.
58 citations
TL;DR: The variation and distribution of esterase isozymes in tuber-bearing Solanums was determined by disc electrophoresis and a hypothesis based on the active enzyme being a tetramer composed of one, two or three types of monomers accounts for the results.
58 citations