Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ESTERASES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,675 records · Page 93Linked to original sources
PubMed1976

Genetic variation of pancreatic esterase isozyme in Japanese quail.

A genetic variation was found in pancreatic esterases of Japanese quail which appeared to be arylesterase. It was found on the cathode side in the agar gel electrophoresis. Three phenotypes, A,B and AB, were observed. These phenotypes were shown to be controlled by one autosomal locus, designated as Es-4, with co-dominant alleles Es-4A and Es-4B. Es-4 esterase isozymes were detected in all the individuals from about 4 days of age, but the activity was very weak. However, it gradually increased to reach a level almost the same as that of a mature quail from about 15 days of age.

Age Factors↗
PubMed1977

Genetic polymorphism of eserine resistant esterases in canine plasma.

Six plasma eserine resistant esterase phenotypes were observed in a population of 1438 dogs consisting of 38 breeds. Analysis of parentage records of the dogs examined revealed that the phenotypic variation of eserine resistant esterases was controlled by 3 codominant alleles ESA, ESB and ESC at one autosomal locus. The gene frequency of ESB was high in most of the breeds examined. Allele ESC was only seen in 5 Japanese native breeds, Akita, Shikoku, Hokkaido, Shinshu-Shiba and Mino-Shiba, and in a Spitz dog. Allele ESA has a low frequency in Japanese breeds but a higher frequency in some of the European breeds tested.

Alleles↗
PubMed1980

Genetic polymorphism of erythrocyte esterase-D in pigs.

The erythrocyte esterase-D (Es-D) of four European-American pig breeds, two Taiwan native pigs (Taoyuan and Short ear breeds), Philippine native pig and wild boar populations (Sus scrofa riukiuanus) in Japan was investigated by using starch gel electrophoresis. Analysis of parentage records of the pigs revealed that the phenotypic variation of erythrocyte esterase-D was controlled by two codominant alleles Es-DA and Es-DB. The allele Es-DB was mostly found in three European-American pig breeds, Landrace (0.100), Hampshire (0.135) and Duroc (0.102). All of the wild boar populations were monomorphic for allele Es-DA.

Alleles↗
PubMed1995

Mutations in the equine plasma transferrin and esterase systems.

Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.

Animals↗
PubMed1980

Localization of non-specific esterase and endogenous peroxidase in the murine epidermal Langerhans' cells.

The localization of the enzymatic activity of non-specific esterase and endogenous peroxidase of the Langerhans' cells in murine epidermal sheets separated with EDTA was observed by means of light and electron microscopy. The Langerhans' cells exhibited non-specific esterase activity in the outer portion of the plasma membrane and endogenous peroxidase activity in the nuclear envelope and the endoplasmic reticulum.

Animals↗
PubMed1985

The relevance of alpha-naphthyl acetate esterases to various monocyte functions.

Human monocytes contain a series of alpha-naphthyl acetate (alpha NA) esterases which are not present in other blood cells and which can be specifically inhibited by bis(4-nitrophenyl)-phosphate (BNPP). This inhibitor is non-toxic at the concentration used and thus enabled studies on the possible significance of this enzyme towards various monocyte functions. BNPP has no noticeable influence on adhesion and spreading of monocytes on glass surfaces, nor does it inhibit the phagocytosis of IgG-coated latex particles. BNPP does, however, diminish the spontaneous cytotoxicity of freshly isolated monocytes towards the erythroleukaemic cell line K562. In the single cell assay in agarose, BNPP treatment of monocytes leads to a decrease in the number of lytic and non-lytic effector-target cell conjugates. In contrast, the antibody-dependent cell-mediated cytotoxicity (ADCC) of monocytes as well as the natural cytotoxicity of lymphocytes towards K562 cells are not influenced by BNPP. The present investigations show that monocyte specific alpha NA esterases are involved in the spontaneous cytotoxicity of monocytes toward tumour cells.

Cell Adhesion↗
PubMed1992

Purification of human monocyte-specific esterase (MSE): molecular and kinetic characteristics.

Human monocyte-specific esterase (MSE) derived from leukaemic AMoL-M5 blast cells was purified to homogeneity by the sequential application of anion-exchange, hydrophobic interaction, affinity and gel filtration chromatographic procedures. The resulting enzymatically active MSE primarily existed as an apparent trimer which, under both reducing and non-reducing conditions, dissociated to an inactive 63.4 kD glycoprotein monomer. Electrophoretic studies further confirmed that purified MSE comprised a narrow series of pI (5.5-6.1) forms and one main charge species. Neuraminidase failed to modify observed pI values for individual MSE isoenzymes, and endoglycosidase H treatment revealed that the deglycosylated form of MSE had an apparent molecular weight of 60.1 kD. In support of the known cytochemical characteristics of human MSE, substrate kinetic studies demonstrated that purified enzyme hydrolysed esters of higher acyl chain length (butyrate > propionate > acetate) but did not show peptidase activity. Amino acid sequencing of the MSE N-terminus further revealed that there was almost complete identity with human alveolar macrophage esterase and close similarities with rat and rabbit liver carboxylesterases. These kinetic and molecular studies are particularly important in elucidating the biological and functional role(s) of one of the few haemopoietic cell enzymes that can be considered truly lineage-specific.

Amino Acid Sequence↗
PubMed1998

Polymorphisms and fluctuations in copy number of amplified esterase genes in Culex pipiens mosquitoes.

In Culex pipiens mosquitoes, A2 esterase alleles are co-amplified with B2 esterase alleles in response to selection with organophosphate insecticides. In this study the amplified A2 and B2 sequences were compared between twelve strains from four continents by restriction mapping. The restriction maps were almost identical in each strain throughout 22 kb surrounding the genes, suggesting that this represents a constant core sequence. A polymorphism was found in two strains collected from Egypt and Kenya in the mid 1980s. This polymorphism was present in all copies of the amplicon, which suggests that a mechanism of sequence homogenization was operating, i.e. concerted evolution. These two strains were almost certainly descendants from the same population and migration probably occurred along the River Nile. Although the maps were almost identical in each strain, dot blotting demonstrated that amplification levels differed by up to 13-fold between strains. Thus the presence of the A2-B2 haplotype cannot be used to indicate the level of amplification or any particular degree of resistance.

Animals↗
PubMed1977

Human leukocyte migration inhibitory factor (LIF). I. Effect of synthetic and naturally occurring esterase and protease inhibitors.

The activity of leukocyte migration inhibitory factor (LIF) obtained from Sephadex-G-100-chromatographed supernatants of concanavalin-A-stimulated human lymphocytes was suppressed by two synthetic serine esterase and serine protease inhibitors (di-isopropylfluorophosphate (DFP) and phenylmethylfulfonyl fluoride (PMSF)). LIF activity was also reduced by the naturally occurring protease inhibitors soybean trypsin inhibitor and aprotinin. The observed effect of DFP and PMSF was irreversible, since elimination of the inhibitors by dialysis did not restore LIF activity. The effect of PMSF was dose-, time-, and temperature-dependent, and hydrolytic products of PMSF as well as sodium fluoride were inactive in blocking LIF. These results suggest that LIF may act as a serine esterase or a serine protease, or both of these, and that this putative enzyme is present in an activated form in supernatants from mitogen-stimulated mononuclear cells.

Aprotinin↗
PubMed1980

T lymphocytes in malignant, non-lymphoid human tumours detected by esterase technique.

The alpha-naphthyl acetate esterase (ANAE) method, leading to distinct brownish-red dots in the cytoplasm of T lymphocytes, was used to identify these cells in cryostat sections from eighteen malignant tumours. Esterase-positive lymphocytes were found in all tumours, the highest number in the peritumoural stroma. The reliability of the method was tested on lymph nodes, on fixed E-rosetting lymphocytes and on cryostat sections from peripheral blood lymphocytes.

Carboxylic Ester Hydrolases↗
PubMed1991

A rapid microtitration plate assay for non-specific esterase.

A simple and convenient colorimetric assay for the quantification of non-specific esterase is described. The assay takes advantage of the microtitration plate format, and the high capacity of repetitive dispensers and the microplate reader for this format. The assay is well suited for the quantification changes in the esterase activity in homogeneous cell populations like monocytes maturing into macrophages.

Animals↗
PubMed1975

Red cell esterase D in studies of paternity cases in the United Kingdom.

The recently discovered genetic polymorphism of human red cell esterase D has been applied to 156 cases of disputed paternity, along with other well-established systems. The results indicate that esterase D is a useful additional genetic marker for use in paternity testing.

ABO Blood-Group System↗
PubMed1997

Functional expression of a tobacco gene related to the serine hydrolase family -- esterase activity towards short-chain dinitrophenyl acylesters.

We have recently reported the isolation of a tobacco gene, hsr 203J, whose transcripts accumulate during the hypersensitive reaction, a plant response associated with resistance to pathogens. We present and discuss here some structural and biochemical properties of the gene product. Nucleotide sequence analysis has shown that the hsr 203J gene contains an open reading frame coding for a polypeptide of 335 amino acids. The predicted amino acid sequence contains the GXSXG motif characteristic of serine hydrolases, and displays limited but significant similarity to lipases and esterases of prokaryotic origin. The hsr 203J gene was expressed in Escherichia coli, and the recombinant protein, purified to near homogeneity, was able to degrade p-nitrophenylbutyrate, a general substrate for carboxylesterases. The enzyme was unable to hydrolyze lipids, and was active on short-chain acyl esters only. The hydrolytic activity was abolished by diisopropyl fluorophosphate and a derivative of isocoumarin, as expected for a member of the serine hydrolase family. Sequence similarities between the tobacco esterase and expressed sequence tags in databases suggest the existence of members of this enzyme family in various plant species.

Butyrates↗
PubMed2000

Characterisation of a Pasteurella multocida esterase gene which confers a hemolytic phenotype in Escherichia coli under anaerobic conditions.

Investigation of the hemolytic phenotype under anaerobic growth conditions of an avian Pasteurella multocida strain, PBA100, resulted in the identification and characterisation of a gene encoding an esterase enzyme, mesA, that conferred a hemolytic phenotype in Escherichia coli under anaerobic conditions. MesA appeared to be expressed and functional under anaerobic and aerobic conditions in both E. coli and P. multocida. A P. multocida mesA mutant was generated which resulted in the loss of acetyl esterase activity under anaerobic conditions. However, this mutation did not cause any attenuation of virulence for mice nor a detectable change to the anaerobic hemolytic phenotype of P. multocida. In E. coli MesA appeared to cause hemolysis indirectly by the induction of the latent E. coli K-12 cytolysin, sheA.

Amino Acid Sequence↗
PubMed2001

Initial degradation of dimethylphthalate by esterases from Bacillus species.

Dimethylphthalate (DMP), one of the phthalate esters, is used in the manufacture of plasticizers, insect repellents, and synthetic fibers, and contributes to environmental pollution. In the present study, we report a novel bacterium belonging to the Bacillus sp., which has the ability to utilize DMP as the sole source of carbon. The esterases from the cell-free extract of the Bacillus de-esterified DMP. Native polyacrylamide gel electrophoresis showed the presence of four isoesterases designated Et1--4. The isoesterases Et-4 and Et-1 showed a higher preference towards DMP hydrolysis as compared with Et-2 and 3. A megaplasmid of about 60 kb was detected in this bacterium. The ability of this bacterium to utilize DMP as the sole source of carbon was lost upon plasmid curing. The isoesterases Et-1--4 were absent in the cell-free extracts of the cured bacterium. The results from our studies clearly demonstrate that de-esterification is the initial step in the degradation of DMP and the genes for these esterases seem to be harbored on the plasmid in this bacterium.

Bacillus↗
PubMed1977

Discrimination of B, T and null lymphocytes by esterase cytochemistry.

A technique has been devised which optimally demonstrates non-specific esterase activity in human blood lymphocytes. The reaction is carried out on smears fixed with formalin vapour, using alpha-naphthol butyrate as substrate at pH 8 and at a low concentration for a short incubation period. The pattern of esterase activity revealed by this method provides a discriminating marker for mature T-lymphocytes, which show dense, localised, dot-like positivity, and a probable marker for 'null' cells in the form of scattered granular positivity. B cells appear to be negative. Monocytes show a clearly different pattern of granular positivity.

Acid Phosphatase↗
PubMed1977

Heterogeneity of acid phosphatase, beta-glucuronidase, and alpha-naphthyl-acetate esterase in normal and leukaemic lymphocytes.

Comparative study of isoenzymic patterns of acid phosphatase, beta-glucuronidase and alpha-naphthyl acetate esterase of normal and chronic lymphocytic leukaemia (CLL) lymphocytes was carried out by means of polyacrylamide gel electrophoresis. The isoenzymograms of acid phosphatase and beta-glucuronidase of leukaemic cells were similar to that of normal lymphocytes. However, different patterns were found in the case of alpha-naphthyl acetate esterase. Two prominent anodal bands were present in CLL lymphocytes; these bands were either absent or very weak in normal cells.

Acid Phosphatase↗