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At least 91 records · Page 5Linked to original sources
PubMed1977

Polymorphism of esterase 11 in Mus musculus, a further esterase locus on chromosome 8.

A further esterase, esterase 11, which exhibits a polymorphism detectable by electrophoresis, has been observed in the house mouse, Mus musculus. In 15 inbred strains and two outbred strains, the ES-11A phenotype has been found, composed of two bands of enzyme activity of greater anodal electrophoretic mobility than the two bands of the ES-11B phenotype found in one inbred strain, one wild stock, and 101 wild mice. In F1 hybrids (IS/Cam X C57BL/Gr), the phenotype shown corresponds to a mixture of the two parental phenotypes. In backcrosses, ES-11 segregates as an autosomal gene, designated Es-11, closely linked to Es-2 and Es-5 on chromosome 8.

Animals↗
PubMed1978

Esterase 13, a new mouse esterase locus with recessive expression and its genetic location on chromosome 9.

A new esterase locus (Es-13) has been identified in Musculus. Strains AEJ/GnRk, LG/J, SJL/J, and SWR/J carry a recessive allele, Es-13b, for a locus possibly involved in the posttranslational modification of a kidney esterase. All other strains observed carried the dominant Es-13a allele. Es-13 was mapped on Chr 9 by recombinant inbred lines and by conventional backcrossing experiments. Backcross data produced the following gene order and map distances: Lap-1 (31.6 +/- 7.5 cM) Es-13 (2.6 +/- 2.6 cM) Mod-1.

Animals↗
PubMed1976

Esterase. XXIII. Electron microscopical demonstration of non-specific esterases in the jejunum of the mouse (Mus musc.) with two quinoline derivatives.

The intracellular distribution of non specific esterases in various villous cells of mouse jejunum was investigated using two substrates, 8-acetoxiquinoline (Q-O-2) and 8-acetyl mercaptoquinoline (Q-S-2) respectively. With the more selectively staining Q-S-2 a uniform reaction was demonstrated in all enterocytes which was mainly located in the endoplasmic reticulum and the nuclear envelope. Possibly it is a matter of a single enzyme being hardly detachable from the membranes. With the non selectively staining Q-O-2 several esterases were demonstrated Es-2, adn Es-9 among them. The main reaction was found in columnar and Goblet cells, in both at all cellular membranes and in the mitochondrial matrix, additionally in cisterns and vesicles of the endoplasmic reticulum and of the Golgi apparatus and at lipid droplets of the former, finally at mucous droplets of the latter. An extracellular reaction was found in the intercellular cleft and between the microvilli of the brush border.

Animals↗
PubMed1980

New polymorphisms of esterase 7 and esterase 8 in inbred strains of rats: tissue expression and linkage studies.

Two new esterase polymorphisms (Es-7 and Es-8) were identified in the testis homogenate of laboratory rats, Rattus norvegicus, by using discontinuous gradient polyacrylamide gel electrophoresis. Es-7 expressed two phenotypes: ES-7A (fast) and ES-7B (slow). Es-8, which migrated in the cathodal region rather than the ES-7 region, also expressed two phenotypes: ES-8A (fast) and ES-8B (slow). Linkage tests among Es-2, Es-7, and Es-8 were made from backcross progeny of the mating (LEJ/Hkm x T/Hok)F1 x LEJ/Hkm. One recombinant in 51 progeny tested was observed between Es-2 and Es-7; however, recombination between Es-2 and Es-8 was not observed in the same progeny. In addition, we show that the esterase polymorphisms of Es-5 in liver homogenate and Es-3 in small intestine homogenate are identical.

Animals↗
PubMed1974

Esterases of Drosophila. II. Biochemical studies of esterase-5 in D. pseudoobscura.

In vitro enzyme hybridization was carried out with combinations of six allozymic variants of Esterase-5 from Drosophila pseudoobscura. Studies on heat stability and specific activity changes accompanying hybridization were done to examine the possible expression of overdominance at the biochemical level. In 11 of 15 combinations no significant change in specific activity was found following hybridization. In two cases hybridization resulted in a decrease in activity in the mixture, while in two cases esterase activity was elevated. Heat stability studies, in several cases, revealed reduced rates of inactivation in in vitro and in vivo heterozygotes compared with homozygotes. From these and other data a model for the molecular mechanism of heterosis is presented.

Animals↗
PubMed1975

Esterase polymorphism in the Adriatic sardine (Sardina pilchardus Walb.). 1. Electrophoretic and biochemical properties of the serum and tissue esterases.

At least four zones of esterase activity designated I, II, III and IV were found after electrophoretic separation of sera and soluble extracts of sardine tissues on starch gel. Each zone consisted of one or more bands that were distinguishable from other zones by electrophoretic mobility, substrate specificity and sensitivity to various inhibitors. Polymorphism was noted in zones I, II and III, while zone IV consisted of a single band. A genetic interpretation of the polymorphism was given for zone I esterases in the tissue, which appears to be controlled by four codominant alleles. The zones designated I, II and IV in the sera and II, III and IV in the liver were characterized as carboxylesterases, zone II in the sera was the only one with cholinesterase activity, while zone I in the liver tissue was unclassifiable.

Animals↗
PubMed1977

Esterase XXV. On the induction of Es-9 esterase of mouse kidney by testosterone.

The Es-9 esterase is expressed in the cortical zone of the NMRI mouse kidney only in the presence of testosterone. In disc electrophoresis, three esterase bands, absent in the control, emerge under the influence of exogenous testosterone, accompanied by the appearance of active sites, as shown by marking with [3H] diisopropyl fluorophosphate ([3H]DFP). It is suggested that the testosterone dependent appearance of Es-9 activity is due to true enzyme induction which requires the presence of an intact testosterone receptor.

Animals↗
PubMed1998

In vitro transesterification of cocaethylene (ethylcocaine) in the presence of ethanol. esterase-mediated ethyl ester exchange esterase-mediated ethyl ester exchange.

This study reports that cocaethylene undergoes an esterase-mediated ethyl ester exchange with ethanol, resulting in an increase in the apparent in vitro t1/2, compared with control conditions. Homogenized liver from male Sprague Dawley rats in pH 7.4 phosphate buffer was centrifuged at 9000g, and the resulting supernatant (S9) fraction was collected. Tubes containing the rat S9 fraction and 50 microM cocaethylene plus aqueous buffer (control), 50 mM ethanol, or 51. 3 mM 2H6-ethanol were incubated at 37 degrees C for 4 hr. Samples were collected from the incubation tubes at various times, extracted with a solid-phase extraction system, and assayed for cocaethylene and 2H5-cocaethylene by GC/MS. Concentration-time profiles were constructed and kinetic parameters were determined. The experiment was repeated in the presence of specific and nonspecific esterase inhibitors. Enzyme kinetic parameters were also determined. Cocaethylene underwent ethyl ester exchange, being converted to 2H5-cocaethylene in the presence of 2H6-ethanol. The average apparent in vitro t1/2 value for cocaethylene (13.0 +/- 1.4 min) incubated with the S9 fraction and buffer only was increased approximately 5-fold (67.8 +/- 0.3 min) in the presence of ethanol. Formation of 2H5-cocaethylene was totally blocked with the addition of bis-(p-nitrophenyl)phosphate but was unaffected by physostigmine. The intrinsic metabolite formation clearance of 2H5-cocaethylene from cocaethylene and 2H6-ethanol (1.92 +/- 0.03 microl/min.mg protein) was several times greater than the corresponding value for cocaethylene formation from cocaine and ethanol (0.94 +/- 0.01 microl/min.mg protein) or 2H6-ethanol (0.87 +/- 0.04 microl/min.mg protein).

Animals↗
PubMed1983

Esterase-17 (ES-17): characterization and genetic location on chromosome 9 of a bis-p-nitrophenyl phosphate-resistant esterase of the house mouse (Mus musculus).

Genetic variation of a new codominantly inherited esterase, designated ES-17, has been discovered in the house mouse using isoelectric focusing in polyacrylamide gels. The ES-17 A phenotype (three bands; isoelectric points, between pH 5.55 and pH 5.90) was found in C57BL/10Sn. LP/J possessed the Es-17B phenotype (three bands; isoelectric points, pH 5.05-5.55). ES-17 was present in all tissues examined, except for hemolysate and serum, and was most clearly expressed in the small intestine. Because of its reaction toward various substrates and inhibitors, ES-17 has tentatively been classified as acetyl esterase (EC 3.1.1.6). ES-17 was shown to be controlled by the structural locus Es-17, located on chromosome 9. From test-cross data, a gene order of Es-17-8.7 +/- 2.5 map units-Mpi-1-10.2 +/- 2.7 map units-Mod-1 was established.

Acetylesterase↗
PubMed1984

Esterase-13 of the rat (Rattus norvegicus) and its homology with esterase-3 of the house mouse (Mus musculus).

A new allele of esterase-13 was detected in various laboratory inbred strains of Rattus norvegicus and designated Es-13c. The activity of ES-13 towards a range of chromogenic substrates, inhibitor profile, isoelectric points and retardation coefficients on polyacrylamide gel electrophoresis were determined. The organ specific expression of ES-13 alleles was investigated and it was shown that kidney homogenates contained a factor which modified the liver enzyme banding pattern in vitro. The features of ES-13 from the rat indicated homology between this esterase and ES-3 from the house mouse, Mus musculus domesticus.

Alleles↗
PubMed1988

Lymph esterases of the house mouse (Mus musculus)--II. The role of esterase-2 in fat resorption.

1. Intralipid infusion into the duodenum of Mus musculus was accompanied by changes in lymph and serum concentrations of two esterase isozymes, ES-1 and ES-2. Whereas ES-1 levels declined in both lymph and serum, ES-2 levels increased 5-fold in lymph within 120 min, and fell to a plateau 3- to 4-fold the fasting level; serum levels of ES-2 increased continually. 2. The changes in lymph ES-2 concentrations were paralleled by lymph triglyceride concentration during Intralipid infusion. Genetically determined differences in the concentration of two allozymes, ES-2B and ES-2D, were reflected in differences in lymph triglyceride levels. The lymph triglyceride concentration was strongly correlated with approximately the cube root of the lymph ES-2 concentration for both allozymes. 3. The source of lymph ES-2 during fat resorption was probably an intracellular jejunal pool; serum ES-2 also re-entered the lymph but this fraction was not influenced by fat resorption. 4. Purified chylomicrons possessed no esterase activity; however, it was postulated that ES-2 plays an essential role in fat resorption and is extruded with the primary chylomicrons from the enterocyte.

Animals↗
PubMed2004

The inhibition of the high sensitive peripheral nerve soluble esterases by mipafox. A new mathematical processing for the kinetics of inhibition of esterases by organophosphorus compounds.

In the study of organophosphorus (OP) sensitive enzymes, careful discrimination of specific components within a complex multienzymatic mixture is needed. However, standard kinetic analysis gives inconsistent results (i.e., apparently different kinetic constants at different inhibitor concentration) with complex multienzymatic mixtures. A strategy is now presented to obtain consistent kinetic parameters. In the peripheral nerve, soluble carboxylesterases measured with the substrate phenylvalerate (PV) are found with extremely high sensitivity to some inhibitors. Tissue preparations were preincubated with mipafox at nanomolar concentrations (up to 100 nM) for different inhibition times (up to 180 min). Inhibition data were analyzed with model equations of one or two sensitive (exponential) components, with or without resistant components. The most complex model was %act=A1e-k1It+A2e-k2It+AR (step 1). From the curve with the highest mipafox concentration (100 nM), the amplitude for the resistant component was determined as AR=15.1% (step 2). The model equation with a fixed AR value was again applied (step 3) to deduce the second-order inhibition rate constants (k1=2.6 x 10(6) M-1 min-1 and k2=0.28 x 10(6) M-1 min-1), being conserved consistently throughout all mipafox concentrations. Finally, using fixed values of AR, k1, and k2, the amplitudes for the two exponential (sensitive) components (A1 and A2) were re-estimated (A1=50.2% and A2=34.2%). The operational process was internally validated by the close similarity with values obtained by directly fitting with a three-dimensional model equation (activity versus time and inhibitor concentration) to the same inhibition data. Carboxylesterase fractions separated by preparative chromatography showed kinetic properties consistent with the kinetically discriminated components. As practical conclusion, for routine analysis of esterases in toxicological studies, a simplified procedure using the inhibition with mipafox at 30 nM, 1 microM, and 1 mM for 30 min is suggested to discriminate the main esterase components in soluble fraction preparations.

Animals↗
PubMed1988

cDNA cloning of esterase 1, the major esterase activity in mouse plasma.

We report here the cloning of a partial cDNA for Esterase 1, the major esterase activity in mouse plasma. A 470 base pair insert was isolated from a lambda gt11 cDNA library constructed from mouse liver poly A+ RNA, and identified by hybrid selected translation. We show that the sexual dimorphism displayed in the plasma levels of this protein is caused by a difference at the level of transcription. In addition, RFLP data using mouse recombinant inbred strains mapped this clone at the Es-1 locus on mouse chromosome 8.

Amino Acid Sequence↗
PubMed1999

Peripheral nerve soluble esterases are spontaneously reactivated after inhibition by paraoxon: implications for a new definition of neuropathy target esterase.

Soluble extracts of chicken peripheral nerve contain detectable amounts of phenyl valerate esterase (PVase) activity (about 2000 nmol/min per g of fresh tissue). More than 95% of this activity is inhibited in assays where substrate has been added to a preincubated mixture of tissue with the non-neuropathic organophosphorus compound (OP) paraoxon (O,O'-diethyl p-nitrophenyl phosphate): residual activity includes soluble neuropathy target esterase (S-NTE) which, by definition, is considered resistant to long-term progressive (covalent) inhibition by paraoxon. However we have previously shown that paraoxon strongly interacts with S-NTE so interfering with its sensitivity to other inhibitors. We now show that, surprisingly, removal of paraoxon by ultrafiltration ('P' tissue) in order to avoid such an interference results in the reappearance of about 65% of total original soluble PVase activity which is inhibited in the presence of this OP. Although a purely reversible non-progressive inhibition might be suspected, kinetic analysis data show a time-progressive inhibition which suggests that such PVase(s) covalently bind paraoxon. Also a time-dependent recovery due to spontaneous reactivation of the PVase activity was observed after dilution of the inhibitor. Gel filtration chromatography of 'P' tissue in Sephacryl S-300 shows that the reactivated activity is associated with proteins of about 100-kDa mass which include S-NTE and an, as yet, unknown number of other PVases. The implications of these findings in the definition of NTE in a target tissue for the so-called organophosphorus-induced delayed polyneuropathy (OPIDP) are discussed.

Animals↗
PubMed1998

Acetyl xylan esterase II from Penicillium purpurogenum is similar to an esterase from Trichoderma reesei but lacks a cellulose binding domain.

Penicillium purpurogenum produces at least two acetyl xylan esterases (AXE I and II). The AXE II cDNA, genomic DNA and mature protein sequences were determined and show that the axe 2 gene contains two introns, that the primary translation product has a signal peptide of 27 residues, and that the mature protein has 207 residues. The sequence is similar to the catalytic domain of AXE I from Trichoderma reesei (67% residue identity) and putative active site residues are conserved, but the Penicillium enzyme lacks the linker and cellulose binding domain, thus explaining why it does not bind cellulose in contrast to the Trichoderma enzyme. These results point to a possible common ancestor gene for the active site domain, while the linker and the binding domain may have been added to the Trichoderma esterase by gene fusion.

Acetylesterase↗
PubMed2000

Comparison of esterase gene amplification, gene expression and esterase activity in insecticide susceptible and resistant strains of the brown planthopper, Nilaparvata lugens (Stål).

Organophosphorus and carbamate insecticide resistance in Nilaparvata lugens is based on amplification of a carboxylesterase gene, Nl-EST1. An identical gene occurs in susceptible insects. Quantitative real-time PCR was used to demonstrate that Nl-EST1 is amplified 3-7-fold in the genome of resistant compared to susceptible planthoppers. Expression levels were similar to amplification levels, with 1-15-fold more Nl-EST1 mRNA in individual insects and 5-11-fold more Nl-EST1 mRNA in mass whole body homogenates of resistant females compared to susceptibles. These values corresponded to an 8-10-fold increase in esterase activity in the head and thorax of individual resistant insects. Although amplification, expression and activity levels of Nl-EST1 in resistant N. lugens were similar, the correlation between esterase activity and Nl-EST1 mRNA levels in resistant individuals was not linear.

Animals↗
PubMed1997

Chromatographic discrimination of soluble neuropathy target esterase isoenzymes and related phenyl valerate esterases from chicken brain, spinal cord, and sciatic nerve.

Neuropathy target esterase (NTE) activity is operatively defined in this work as the phenyl valerate esterase (PVase) activity resistant to 40 microM paraoxon but sensitive to 250 microM mipafox. Gel filtration chromatography with Sephacryl S-300 of the soluble fraction from spinal cord showed two PVase peaks containing NTE activity (S-NTE1 and S-NTE2). The titration curve corresponding to inhibition by mipafox was studied over the 1-250 microM range, in the presence of 40 microM paraoxon. The data revealed that S-NTE1 and S-NTE2 have different sensitivities to mipafox with I50 (30 min) values of 1.7 and 19 microM, respectively. This was similar to the pattern observed in the soluble fraction from sciatic nerve with two components (Vo peak, or S-NTE1; and 100-K peak, or S-NTE2) with different sensitivity to mipafox. However, in the brain soluble fraction, only the high-molecular-mass (>700-kDa) peak or S-NTE1 was obtained. It showed an I50 of 5.2 microM in the mipafox inhibition curve. The chromatographic profile was different on changing the pH in the subcellular fractionation. When the homogenized tissue was centrifuged at pH 6.8, the Vo peak activity decreased in the soluble fraction from these nerve tissues. This suggests that the Vo peak could be related to materials partly solubilized from membranes at higher pH. The chromatographic pattern and mipafox sensitivity suggest that the different tissues have a different NTE isoform composition. S-NTE2 should be a different entity than S-NTE1 and particulate NTE. The potential role of soluble forms in the mechanism of initiation or promotion of neuropathy due to organophosphorus remain unknown.

Animals↗