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PubMedDate not supplied

[Isolation and various properties of cholesterol esterase from swine liver].

Neutral cholesterol esterase from cytosol of porcine liver tissue was isolated by means of ion-exchange chromatography on DEAE- and CM cellulose and gel filtration on Sepharose 6B. Specific activity of the isolated cholesterol esterase using cholesteryl-14C-oleate as substrate was 61.2 nmole/mg/hr. Total activity of the enzyme was increased during ion-exchange chromatography as a result of removing of possible inhibitors or endogenic lipids. The enzyme was separated by means of gel filtration on Sepharose 6B into 3 active forms with molecular masses, approximately 200,000, 60,000 and 30,000 daltons. Cholesterol esterase from porcine liver tissue was distinct from the pancreatic enzyme by its ability to hydrolyze substrate in absence of bile acids.

Animals↗
PubMed1979

IgE mediated triggering of rat basophil leukemia cells: lack of evidence for serine esterase activation.

Inhibition of mediator release from mast cells and basophils by diisopropylfluorophosphate (DFP) and other organophosphorus compounds known to inhibit serine esterases has in the past led to the hypothesis that immunologic triggering of these cells involves an activatable serine esterase. In this study we have shown that two nonphosphorylating or poorly phosphorylating structural analogs of two potent phosphorylators inhibit release of incorporated serotonin from cultured rat basophil leukemia cells. We conclude that, by itself, inhibition of immunologic mast cell triggering by phosphorylating organophosphorus compounds can no longer be considered evidence for involvement of an activatable serine esterase in mast cell triggering.

Animals↗
PubMed1979

Histochemical studies for 5'-nucleotidase and alpha-naphthyl (non-specific) esterase in lymphocytes from patients with primary immunoglobulin deficiencies.

Lymphocytes from patients with primary immunodeficiency were tested histochemically for ecto 5'-nucleotidase (5'N) and alpha-naphthyl (non-specific) esterase. More than half the patients with 'common variable' hypogammaglobulinaemia, all those with X-linked hypogammaglobulinaemia and some of those with selective IgA deficiency had a very low percentage of lymphocytes staining for 5'N as compared to controls. A lack of B cells probably explains the finding in X-linked hypogammaglobulinaemia, but does not fully explain the results in the other groups. Most patients with 'common variable' hypogammaglobulinaemia had a very low percentage of lymphocytes with granular staining for alpha-naphthyl (non-specific) esterase in contrast to normal numbers in those with X-linked hypogammaglobulinaemia and most of those with selective IgA deficiency. Granules containing non-specific esterase are characteristically found in 'mature' T lymphocytes. The enzyme abnormalities in the T and B cells of 'common variable' hypogammaglobulinaemic patients could be explained by 'immature' cell types.

Adolescent↗
PubMed1979

Cellular esterase activity: estimation by fluorescein diacetate hydrolysis.

Quantitative estimation of cellular esterase activity makes it possible to differentiate cells and cell subpopulations. The fluorescence of fluorescein obtained by hydrolysis from fluorescein diacetate is detected and used for measuring the esterase activity. The method described is suitable for the quantitative determination of esterase activity in human lymphocytes.

Acetates↗
PubMed1984

Serum esterase activity in reactive systemic amyloidosis and its relation to amyloid A degrading activity.

Patients with reactive systemic amyloidosis have a reduced ability to degrade amyloid A protein fibrils in vitro. The amyloid A degrading activity in serum has been attributed to a neutral serine protease or proteases. Our results show that patients with reactive systemic (amyloid A) amyloidosis have low activities of two serum esterases, namely, arylesterase and paraoxonase, whereas the activity of a third esterase, cholinesterase, is normal. The combination of reduced arylesterase (less than 55 kU/L) plus reduced paraoxonase activity (less than 35 U/L) was found in 32% of patients with rheumatoid arthritis complicated by amyloidosis, but in only 5% of a control nonamyloid patient group, including patients with rheumatoid arthritis, liver disease, and hypoalbuminemia (p less than 0.001). A significant correlation between serum arylesterase and amyloid A degrading activity was found (patients with rheumatoid arthritis plus amyloidosis, n = 31, r = 0.51, p less than 0.01; all patients, n = 95, r = 0.34, p less than 0.001). Our results suggest that the amyloid A degrading activity may be closely related to the esterase activity in serum.

Adolescent↗
PubMed1977

Relationship of age and sex to postheparin esterase activity.

Postheparin esterase (E. C. 3.1.1.1.) activity was studied in 130 women and 126 men in whom the medical findings were consistent with their age. The test subjects were divided into 5 age groups from 17 to 73 years. Postheparin esterase activity was found to be statistically significantly higher in men than in women. In men it was uncorrelated to age, while in women it rose with advancing age. Changes in postheparin esterase in women appear to be correlated to the hormonal state of the organism.

Adolescent↗
PubMed1982

Identification of T lymphocytes by a histochemical stain for alpha naphthyl acetate esterase activity.

Lymphocyte suspensions and peripheral blood smears from 20 normal individuals were examined for nonspecific esterase activity, using alpha naphthyl acetate as substrate and hexazotized pararosanilin stain. Lymphocytes show intense, focal, red "dot-like" activity; monocytes show diffuse reddish granulation. B lymphocytes do not react. Critical variables of the procedure include: use of proper anticoagulant; fixation for 30-180 seconds; incubation with substrate 3-5 hours; and pH 5.8. Comparison of results with conventional E rosette methodology showed 53-63% rosettes; 50-58% esterase-positive lymphocytes in cytocentrifuge preparations and 47-59% esterase-positive lymphocytes on peripheral blood films. Technical advantages of the procedure favor it as an alternative method for assessing T lymphocytes.

Esterases↗
PubMed1984

[The peptidase site of butyrylcholinesterase is distinct from the esterase site].

Highly purified human plasma butyrylcholinesterase was inhibited by reversible inhibitors of esterase activity and modified by active-site-directed irreversible inhibitors of esterases and proteases. Peptidase and esterase activities of inhibited enzyme were simultaneously essayed from rates of hydrolysis of substance P (first cleavage) and butyrylthiocholine respectively. Inhibition parameters values and rates of inactivation of the two activities provide evidence that the peptidasic site is distinct from the esteratic site.

Binding Sites↗
PubMed1983

Sequential induction of phospholipid methylation and serine esterase activation in a B cell differentiation factor (BCDF)-stimulated human B cell line.

The incubation of CESS cells with BCDF induced phospholipid methylation, i.e., 3H-methyl incorporation into phosphatidylcholine and phosphatidyl-N-monomethyl-ethanolamine, within 15 to 30 min. A threefold increase of 3H-DFP-binding was also observed in BCDF-stimulated CESS cells 2 hr after stimulation, showing the activation of serine esterase after phospholipid methylation. The inhibitors of methyltransferase, SIBA, adenosine, or HEH showed a dose-dependent inhibitory effect not only on phospholipid methylation but also on serine esterase activation and on BCDF-induced IgG production; DFP inhibited IgG production but not phospholipid methylation. The treatment of cells with DFP in the presence of SIBA abrogated the irreversible inhibitory effect of DFP on IgG production. These results showed that BCDF stimulation induced phospholipid methylation that set the stage for serine esterase activation and IgG induction.

Antibody-Producing Cells↗
PubMed1984

Distribution of simple esterase in the nuclei and fiber tracts of the medulla oblongata of squirrel (Funambulus palmarum).

The distribution of simple esterase has been studied in the nuclei and fiber tracts of the medulla oblongata. The simple esterase activity has mainly been observed in the grey matter. The white matter did not reveal enzymatic activity. In the grey matter also the cranial nerve nuclei are intensely stained as compared to intrinsic and reticular nuclei. The distributive pattern of simple esterase in the nuclei has been discussed in relation to its metabolic involvement in brain.

Animals↗
PubMed1984

Isolation and characterization of a murine serum esterase which hydrolyzes a tumor promoter, 12-O-tetradecanoyl phorbol 13-acetate.

An enzyme which catalyzes the following esterase reaction was isolated from mouse serum: 12-O-tetradecanoyl phorbol 13-acetate (TPA) + H2O----phorbol 13-acetate + tetradecanoic acid. The recovery was 0.18% of total serum protein and 820-fold purification was achieved. The enzyme is composed of a single polypeptide chain with sugar moiety; its molecular weight was estimated to be 77,000. Its sugar content is 15%, the isoelectric point was 4.3, and the alpha-helix content was 15.3% . The activity is stable between pH 5 and 9 under 40 degrees C; it is insensitive to 2-mercaptoethanol and is not dependent on divalent cations. The optimal pH is around 7.5. The apparent Km for TPA is 6.6 X 10(-7)M. The hydrolysis of [3H]TPA is inhibited by phorbol diesters and phorbol 12-myristate, but not by phorbol and phorbol 13-acetate. The activity is inhibited to some extent by phosphatidylcholine, cholesterol, and lanosterol, but not by free fatty acids, fatty acid esters of glycerol, cholesterol esters, or cholestanol. The enzyme hydrolyzes ester linkages, but not peptide linkages of synthetic substrates. Esterase inhibitors and serine-reactive reagents affect the activity. Although sera from rodents displayed strong activity, such activity was not detected in human serum. Unlike lipoprotein lipase, the serum enzyme activity was not enhanced by treatment of the animal with heparin. These characteristics and the amino acid composition do not agree with any of the reported characteristics of known serum enzymes with esterase activity.

Amino Acids↗
PubMed1980

[Distinctive profiles of esterases from Klebsiella pneumoniae, K. oxytoca, Enterobacter aerogenes and E. gergovia].

Cellular esterases of 14 strains of Klebsiella pneumoniae, 14 strains of K. oxytoca, 16 strains of Enterobacter aerogenes and 16 strains of E. gergoviae were analysed by polyacrylamide-agarose gel and polyacrylamide gradient gel electrophoresis. Four principal esterase bands and nine minor bands, differing in their activity towards synthetic substrates and in their sensitivity to heat and to di-isofluoropropyl phosphate (DEP) were defined. The comparative distribution of bands showed that the four species analysed were characterized by distinct electrophoretic patterns of their esterases.

Electrophoresis, Polyacrylamide Gel↗
PubMed1980

Localization and origin at rat intestinal cholesterol esterase determined by immunocytochemistry.

Monospecific rabbit antisera to rat pancreas cholesterol esterase were employed in the unlabeled antibody enzyme method of immunocytochemistry in combination with the horseradish peroxidase--antihorseradish peroxidase complex to localize this pancreatic enzyme within the wall of rat small intestine. Intestinal rings were fixed in paraformaldehyde with satisfactory preservation of structure and retention of cholesterol esterase antigenic determinants. Fixed sections, 6 micrometers thick, were stained. In the light microscope, specific reaction product, represented by intense brown areas, was uniformly distributed within the absorptive cells but was notably absent from the microvillar membrane. Reaction product was also seen within the laminapropria and submucosa. In contrast, reaction product was absent from sections of proximal intestine surgically deprived of pancreatic juice for 72 hours. Furthermore, the intensity of staining in sections of normal intestine decreased with increasing distance from the pancreatic duct. These observations support the concept that "intestinal" cholesterol esterase is of pancreatic origin. This enzyme is localized within the cells as opposed to the absorptive surface.

Animals↗
PubMed1980

[Histochemical and biochemical study of the hippocampus and neocortex of the wistar rat. II. The activity of carboxylic acid esterases and transmitter enzymes after a learning experiment].

In the present paper the behaviour of the enzymes monoaminoxidase, GABA-transaminase, acetylcholinesterase, nonspecific cholinesterase, A-, B-, C-esterase and acid phosphatase was investigated by histochemical and biochemical methods for 1 min, 1, 4 and 24 h after a "brightness-discrimination" of male wistar rats in a Y-chamber. Learning induced significant changes of activity of the B-esterase in the hippocampus region 4 h (increase of 30%) and 24 h (decrease of 25%) and of the acetylcholinesterase in the cingular cortex 4 h after training (increase of 38%) are to be observed and regarded and discussed as hints for a changed protein synthesis (B-esterase) or altered synaptic activity (acetylcholinesterase). On the strength of these results and various findings in the literature it may be reputed as sure, that the protein synthesis of the cells of hippocampus in evident. Certain proteins show increased rates of synthesis by the influence of a learning experiment. These proteins are at least partially enzymes, serving as extension of the protein synthesis apparatus of the neurons and may be regarded as part mechanism of the intracellular regulation of the synaptic connectivity.

4-Aminobutyrate Transaminase↗
PubMed1981

[Comparison by electrophoresis of esterases of Yersinia enterocolitica and Yersinia pseudotuberculosis].

Esterases of 32 strains of Y. enterocolitica and of 16 strains of Y. Pseudotuberculosis were compared by electrophoresis in polyacrylamide-agarose gel and by electrophoresis in a 4 to 30% polyacrylamide gradient gel. Differences observed in electrophoretic distributions and in molecular weights of esterases defined distinct esterase patterns for these two species.

Electrophoresis, Polyacrylamide Gel↗
PubMed1978

[About the polymorphisms of esterase D and glyoxalase I and their forensic application (author's transl)].

Phenotypes of esterase D and glyoxalase I were determined electrophoretically in samples from Northern Germany. Gene frequencies: EsD1 = 0,889 (n = 1430), GLO1 = 0,415 (n = 865). The data of 295 (EsD) and 153 (GLO) mother/child combinations were in full accordance with the genetic model of two codominant alleles at an autosomal locus. Esterase D typing has proved successful in bloodstains up to three weeks old. The forensic scope of serological systems is discussed intensively. According to our own data and the results presented in the literature esterase D and glyoxalase I have proved to be useful additional markers for use in cases of disputed paternity.

Blood Group Antigens↗
PubMed1982

[Percentage of monocytes in preparations of mononuclear cells from normal subjects: evaluation by a new rapid method for the identification of esterase-positive cells].

A rapid suspension method for alpha-naphthyl acetate esterase staining has been utilized to evaluate monocytes percentages in Ficoll-Paque separated mononuclear cells (MC) from normal individuals. In MC preparations from 24 normal subjects a mean percentage of 8% monocytes has been found, with a range from 2% to 20%. Cell fractions depleted of T-lymphocytes by rosette sedimentation showed 43% of esterase positive cells (range 31-53%), while very few monocytes (2%) appeared to contaminate the preparations of E-rosetting cells. The method for esterase staining of monocytes while they are in suspension is very simple and permits a rapid and accurate evaluation of monocyte percentages in mixed cell preparations.

Adult↗
PubMedDate not supplied

[Characteristics of esterase expression in interspecific hybrids of Drosophila of the group virilis].

A spectrum of esterase isozymes was studied in the larvae, adults and isolated seminiferous bulbs of hybrids D. virilis X D. littoralis. Different esterase isozymes were shown to be expressed codominantly in all cases studied. The differences found in the activity of paternal fractions at certain developmental stages were due to the preservation of species specific differences in the temporal dynamics of expression of some esterase isozymes.

Animals↗