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PubMed2005

Plasma B-esterase activities in European raptors.

B-esterases are serine hydrolases composed of cholinesterases, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and carboxylesterase (CbE). These esterases, found in blood plasma, are inhibited by organophosphorus (OP) and carbamate (CB) insecticides and can be used as nondestructive biomarkers of exposure to anticholinesterase insecticides. Furthermore, B-esterases are involved in detoxification of these insecticides. In order to establish the level of these enzymes and to have reference values for their normal activities, total plasma cholinesterase (ChE), AChE and BChE activities, and plasma CbE activity were determined in 729 European raptors representing 20 species, four families, and two orders. The diurnal families of the Falconiforme order were represented by Accipitridae and Falconidae and the nocturnal families of the Strigiforme order by Tytonidae and Strigidae. Intraspecies differences in cholinesterase activities according to sex and/or age were investigated in buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus), barn owls (Tyto alba), and tawny owls (Strix aluco). Sex-related differences affecting ChE and AChE activities were observed in young kestrels (2-3-mo-old) and age-related differences in kestrels (ChE and AChE), sparrowhawks (AChE), and tawny owls (ChE, AChE, and BChE). The interspecies analysis yielded a negative correlation between ChE activity and body mass taking into account the relative contribution of AChE and BChE to ChE activity, with the exception of the honey buzzard (Pernis apivorus). The lowest ChE activities were found in the two largest species, Bonelli's eagle (Hieraaetus fasciatus) and Egyptian vulture (Neophron percnopterus) belonging to the Accipitridae family. The highest ChE activities were found in the relatively small species belonging to the Tytonidae and Strigidae families and in honey buzzard of the Accipitridae family. Species of the Accipitridae, Tytonidae, and Strigidae families were characterized by a BChE contribution that dominated the total ChE activity, while in the species of the Falconidae family, AChE activity dominated. With the exception of the barn owl, CbE activity (eserine-insensitive alpha-naphthyl acetate esterase [alpha-NAE] activity) in all species was almost absent or very low. The values obtained in this study for ChE, AChE, and BChE activities and the AChE:BChE ratios for buzzard, kestrel, barn owl, and tawny owl provide a good estimate of the normal values in free-living individuals of these European species. They can be used as a baseline to evaluate the effect of anticholinesterase insecticides in the field.

Age Factors↗
PubMed1992

[Biochemical aspects of the toxic effects of Supermethrin and the histochemical activity of alkaline phosphatase, acid phosphatase and non-specific esterase in subchronic poisoning in sheep].

Fifteen Slovak Merino sheep were included in the experiment. The animals weighing 21-28 kg were divided into three groups per five animals. In a six-week feeding experiment the animals of group I were given 50 mg supermethrin per kg live weight per day while those of group II received 200, and from week four of the experiment 300 mg supermethrin per kg live weight per day. During the experiment changes of aspartate aminotransferase (EC 2.6.1.1), alanine aminotransferase (EC 2.6.1.2), acetylcholine esterase (EC 3.1.1.7), urea und creatinine levels in blood serum were observed. Six weeks after supermethrin treatment the sheep were slaughtered and histochemical evaluation of alkaline phosphatase (EC 3.1.3.2), acid phosphatase (EC 3.1.3.1) and non-specific esterase (EC 3.1.1.1) was carried out in liver, kidney, duodenum, jejunum and ileum. In the course of the experiment changes of the enzymatic activities of aspartate aminotransferase observed in both experimental groups of sheep were similar to those seen in the control group of animals (Tab. I). As compared to the starting values, no significant changes in the activity of alanine aminotransferase were observed in group II of the experiment and in the controls. However, a significantly decreased alanine aminotransferase activity could be seen in the blood serum of sheep of group I (Tab. II). In both experimental groups of animals no significant changes in the acetylcholine esterase could be seen (Tab. III). As compared to the starting values, no significant changes were observed in creatinine levels of the control and the 1st experimental group of sheep (Tab. IV). In the sheep of the 2nd group a temporary significant decrease (p < 0.05) in creatinine levels was seen. The dynamics of urea levels was similar to starting values in all animals throughout the experiment Tab. V). In the control group of animals (Fig. 1) the high density of reaction product of alkaline phosphatase was determined in the microvilli of enterocytes of the small intestine. In the small intestine of the animals of both experimental groups, the activity of this enzyme was shown to be located in the same zone (Fig. 2). In all experimental animals in the parenchyma of the liver and kidney no significant changes could be observed. In both experimental and control animals the high activity of acid phosphatase was demonstrated to be located especially in the cytoplasma of enterocytes. The activity of non-specific esterase was located in the cytoplasma of enterocytes of the small intestine, in the intestinal crypts its activity was slight up to high.(ABSTRACT TRUNCATED AT 400 WORDS)

Acid Phosphatase↗
PubMedDate not supplied

Leukocyte esterase and protein levels in saliva, as indicators of gingival and periodontal diseases in children.

PURPOSE: This study was to determine if dip stick assays of children's saliva for leukocyte esterase or protein (Serim Research Corporation, Elkhart, Ind) reflect the presence or severity of gingival or periodontal diseases in children. METHODS: The study included 13 children with periodontitis [study group] and a control group of 17 children without periodontitis. The saliva leukocyte esterase and protein values (scales from 1 to 4) were tested with dip stick analyses. The gingival (GI) and plaque indices (PI) presence and number of sites with periodontitis, demographic data, systemic condition, caries prevalence, and the presence of dental restorations were recorded and their relationship to leukocyte esterase or protein values were analyzed. RESULTS: Most children had a protein value of 2 or 3 or a leukocyte esterase value of > or = 3. Significant differences in the distribution of protein values by the presence/absence of periodontitis (chi-square, P<0.001), or the number of sites with periodontitis by protein value (chi-square, P=.005; ANOVA, P=.03) were evident; No. 4 protein values were found only in children with periodontitis, and No. 2 and No. 3 protein values were mostly found in children without it. CONCLUSIONS: Dip stick protein analysis of saliva of children has the potential to differentiate children with periodontitis or with fewer periodontal lesions.

Aggressive Periodontitis↗
PubMed1992

Overexpression and purification of ferric enterobactin esterase from Escherichia coli. Demonstration of enzymatic hydrolysis of enterobactin and its iron complex.

The Escherichia coli ferric enterobactin esterase gene (fes) was cloned into the vector pGEM3Z under the control of the T7 gene 10 promoter and overexpressed to approximately 15% of the total cellular protein. The ferric enterobactin esterase (Fes) enzyme was purified as a 43-kDa monomer by gel filtration chromatography. Purified Fes preparations were examined for esterase activity on enterobactin and its metal complexes and for iron reduction from ferric complexes of enterobactin and 1,3,5-tris(N,N',N"-2,3-dihydroxybenzoyl)aminomethylbenzene (MECAM), a structural analog lacking ester linkages. Fes effectively catalyzed the hydrolysis of both enterobactin and its ferric complex, exhibiting a 4-fold greater activity on the free ligand. It also cleaved the aluminum (III) complex at a rate similar to the ferric complex, suggesting that ester hydrolysis of the ligand backbone is independent of any reductive process associated with the bound metal. Ferrous iron was released from the enterobactin complex at a rate similar to ligand cleavage indicating that hydrolysis and iron reduction are tightly associated. However, no detectable release of ferrous iron from the MECAM complex implies that, with these in vitro preparations, metal reduction depends upon, and is subsequent to, the esterase activity of Fes. These observations are discussed in relation to studies which show that such enterobactin analogs can supply growth-promoting iron concentrations to E. coli.

Carboxylic Ester Hydrolases↗
PubMed1978

[Esterase activity of the mitochondria oligomycin-sensitive ATPase complex].

It was found that mitochondrial oligomycin-sensitive ATPase (OS-ATPase) possesses the esterase activity with respect to some carboxylic acid esters with phenols and arylalcane alcohols. The substrate specificity of the esterase found was studied. The effects of some inhibitors and activators of ATPase on the enzyme activity were demonstrated. It was found that ADP inhibits the enzyme from submitochondrial particles containing factor F1 and does not inhibit the enzyme from the particles devoid of this factor. The data obtained suggest that esterase is localized in the hydrophobic part of the oligomycin-sensitive ATPase complex and are indicative of the functional interrelationship between the esterase and ATPase activities.

Adenosine Triphosphatases↗
PubMed1988

Highly lytic in vivo primed cytolytic T lymphocytes devoid of lytic granules and BLT-esterase activity acquire these constituents in the presence of T cell growth factors upon blast transformation in vitro.

Demonstration of C-like "rings," lytic granules, and the Ca2+-dependent lytic proteins--perforin/cytolysin--thereof, in certain cytocidal lymphocytes has led to the hypothesis of a mechanism of lytic granule-exocytosis and a common terminal lytic step in lymphocyte and C-induced lysis. However, neither cytolytic granules, nor formation of C-like rings during lysis have been detected in mature, highly potent, peritoneal exudate CTL (PEL) derived directly from the site of allograft rejection or in cytocidal hybridomas derived from them (PEL hybridomas). We now report that when stimulated in vitro in the presence of Con A supernatant, as a source of T cell growth factors (TCGF) or rIL-2, small in vivo primed PEL transform into large, dividing cytolytic T cells (PEL blasts) that express the same lytic specificity of the original PEL in short term lytic assays. The PEL blasts, in contrast to PEL, possess massive quantities of lytic granules, and protease (N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester esterase) (BLT-esterase) activity as well as non-specific, cell-mediated cytolytic activity in a long term (4-h) assay. These results suggest that the proposed lytic mechanism involving exocytosis of lytic granules, perforin, and BLT-esterases and the formation of 10 to 20-nm lesions may apply to lysis induced by granule-containing effectors such as large granular lymphocytes and TCGF-dependent CTL lines, such as PEL blasts. However, killing by mature, in vivo primed CTL, such as PEL or their hybridomas, appears to be effected through an alternative, contact-induced, self-destruction process(es) of the target not involving secretory lytic granules or the above lesions. Hence, although the expression of lytic granules and BLT-esterase activities in cytolytic lymphocytes devoid of these components is induced by TCGF, these cellular constituents are not necessary for the expression of CTL-mediated target cell lysis by mature effector cells.

Animals↗
PubMed1987

An accessory protein identical to mouse egasyn is complexed with rat microsomal beta-glucuronidase and is identical to rat esterase-3.

We report biochemical, immunological, and genetic studies which demonstrate that an accessory protein with the essential features of mouse egasyn is complexed with and stabilizes a portion of beta-glucuronidase in microsomes of rat liver. The accessory protein exists as a complex with beta-glucuronidase since it coprecipitates with beta-glucuronidase after treatment of extracts with a specific beta-glucuronidase antibody. The two proteins are associated by noncovalent bonds since they are easily dissociated at elevated temperatures. Only 20-25% of total liver accessory protein is complexed with microsomal beta-glucuronidase. The remainder exists as a free form. The molecular weight of the accessory protein is 61 to 63 kDa depending upon the rat strain of origin. This protein, like mouse egasyn, has esterase catalytic activity and is concentrated in microsomes. The accessory protein is genetically polymorphic with at least four alleles. Combined biochemical and genetic evidence indicates it is identical with esterase-3 of the rat. Also, both mouse egasyn and rat esterase-3 react with antisera to egasyn and to rat esterase-3, indicating they are homologous proteins. Several inbred rat strains lack microsomal beta-glucuronidase. The same strains lack the accessory protein, suggesting that stabilization of beta-glucuronidase in rat microsomes requires egasyn.

Alleles↗
PubMed1984

Isolation and properties of nonspecific esterase of murine L 1210 leukemia cells.

Nonspecific esterases of mouse lymphatic leukemia cells L 1210 were isolated and partly purified by gel filtration or DEAE Sephadex ion exchange chromatography. Two forms of esterases of differing molecular weight were found. Both esterases have optimum pH 7.2 and are inhibited by serine esterase inhibitors as well as by thiol reagents. They are not influenced by chelating agent (EDTA).

Animals↗
PubMed1995

Inhibition of activation of human T lymphocytes by the complement C1 esterase inhibitor.

The major histocompatibility complex (MHC) class I molecules have been shown to be substrates to both of the complement C1 esterases. The effect of a C1 esterase-mediated cleavage of the MHC class I molecules on the activation process of lymphocytes was investigated by including the complement C1 esterase inhibitor (C1-Inh) in the medium during activation of human peripheral lymphocytes by staphylococcal enterotoxin A (SEA). The C1-Inh was shown to inhibit the activation of both CD4+ and CD8+ cells. No effect on activation of B lymphocytes was recorded, although the complement C1 complex was shown to bind to the B lymphocytes. Furthermore, the C1 complex bound to mononuclear cells was shown to be cleaved into molecular weights corresponding to the activated forms of the C1 esterases. The effect of the C1-Inh was much more pronounced at low cell density and the inhibition was not affected by the addition of interleukin-2 (IL-2). However, the inhibition was reduced when the cells were disturbed by addition of new portions of C1-Inh, 24 and 48 hr after the initiation of the activation. This indicates that the C1-Inh interference with the activation of T lymphocytes is mediated through a mechanism that requires some form of cell contact.

Complement C1↗
PubMed1995

Abnormalities of esterase and glycogen in developing macrophages in non-Hodgkin's lymphoma: a quantitative cytochemical study.

Integrating microdensitometry has been used to quantitate changes in 4 cytoplasmic enzymes (NADH dehydrogenase, succinate dehydrogenase, acid phosphatase and alpha-naphthyl butyrate esterase), DNA, RNA and glycogen in developing macrophages from 17 patients with non-Hodgkin's lymphoma and 19 normal subjects. Cytochemical measurements were made at intervals over 6 days of suspension culture; over 16 000 individual cells were examined in total and the results subjected to analysis of variance. While the levels of enzymes and RNA of both groups showed increases over the period of culture, the levels of alpha-naphthyl butyrate esterase in the patients' cells were consistently lower than the corresponding values for the normal cells and glycogen levels were higher, these differences satisfying the pre-determined requirements for statistical significance. It is concluded that (a) maturational changes take place in cytochemical constituents of developing macrophages of non-Hodgkin's lymphoma (b) there are disturbances affecting the amounts of the specific enzyme alpha-naphthyl butyrate esterase and glycogen (c) these abnormalities may be part of a compromise of host defense mechanisms by the disease, although a pre-existing defect in esterase increasing the susceptibility to malignancy is another possibility, and (d) the methods used may be of value in future investigations of the cause of the disturbances and their correction.

Acid Phosphatase↗
PubMedDate not supplied

Search for androgen response elements in the proximal promoter of the canine prostate arginine esterase gene.

We have demonstrated the binding of the recombinant DNA binding domain of the rat androgen receptor to a DNA sequence of the canine prostate arginine esterase gene and have determined the functional significance of this sequence in transient transfection experiments. One of the binding sites was localized to a region (-172 to -148 bp) containing the sequence AGGACAACAGGTGTT that has 73% homology with the prostate-specific antigen (PSA) androgen response element (ARE) found at a similar position in the PSA promoter. Competition experiments showed that the androgen receptor had an approximately 100-fold more affinity for the PSA ARE than for the arginine sequence at -172 to -148. Transient cotransfection of 5'-deletion mutants of the arginine esterase promoter and 5'-flanking sequences driving the activity of the reporter gene along with the rat androgen receptor expression vector yielded only negligible inductions of chloramphenicol acetyl transferase (CAT) activity when dihydrotestosterone (DHT) was added to the culture medium. The introduction of one to four repeats of the -172 to -148 sequence of the arginine esterase gene upstream of the basal promoter of the mouse p12 gene in p12.108 also resulted in a minimal induction of CAT activity compared with a 10-fold induction of PSA AREs under similar conditions. These results suggest that the regulation of the canine arginine esterase gene by androgens is most probably achieved by mechanisms that differ from the ones prevailing with the human PSA and kallikrein-2 (hKLK2) genes.

Androgens↗
PubMed1996

Esterase inhibitors diminish the modulation of gene expression by butyric acid derivative, pivaloyloxymethyl butyrate (AN-9).

Pivaloyloxymethyl butyrate (AN-9) belongs to the family of acyloxyalkyl ester prodrugs of carboxylic acids which undergo intracellular hydrolysis to yield butyric acid (BA). We have previously shown that AN-9 and BA reduce the level of c-myc and enhance c-jun transcripts in HL-60 cells, and that the differentiation of these cells, induced by AN-9, is dependent on the presence of intracellular esterases. In this study we show that esterase inhibitors abolish the changes induced by AN-9 on c-myc and c-jun expression. In contrast, esterase inhibitors do not change the effects of BA on c-myc or c-jun. Interestingly, these inhibitors affect the modulation induced by both AN-9 and BA on the retinoblastoma tumor suppressor gene. These data suggest that AN-9 is indeed a prodrug of BA and that prior intracellular hydrolysis by esterases is material for AN-9 activity.

Aniline Compounds↗
PubMed1997

[Resistance to organophosphate insecticides in Culex pipiens L. (Diptera: Culicidae) and first signal of the presence of A5-B5 esterase in Italy].

After a short review on insecticide resistance in mosquitoes, the results of a study on organophosphate (OP) resistance, carried out on 2 Culex pipiens L. field populations from North-eastern Italy, are reported. The A1 an A4-B4 or A5-B5 esterases were detected in our sample by starch gel electrophoresis. In order to differentiate between A4-B4 and A5-B5 esterases, restriction fragment length polymorphism (RFLP) analysis at the esterases B locus was performed: both A4-B4 and A5-B5 aplotipes were found in one of the studied populations. This is the first record of A5-B5 esterases in continental Europe.

Animals↗
PubMed1960

Studies on immune cellular injury. II. Functional role of C'1 esterase in immune cytotoxicity.

An initial separation of reaction stages in immune cytoxicity is described. Primary isolates of normal human amnion cells were reacted first with specific rabbit gamma(2)-globulin antibody, then with human C'1 esterase in the presence of Ca(++), and finally with human C'2, C'3, and C'4 in the presence of Mg(++). Cytotoxicity, as measured by uptake of trypan blue, occurred only when these reactions were performed in the order given and did not occur when any of the constituents was omitted. Inhibition of immune cytotoxicity was achieved with partially purified preparations of human serum inhibitor of C'1 esterase under certain experimental conditions. The data are discussed in relation to the role of C'1 esterase in initiating complement action and the partial biochemical definition of an early event in immune cytotoxicity.

Animals↗
PubMed1954

Distribution of esterase in gastric mucosa.

Sections of frozen-dried stomach mucosa of the rabbit cut at various levels from the surface were analyzed for esterase activity in relation to the proportions of cell types present. Aside from the fraction attributable to extracellular esterase all the esterase activity appears to be in proportion to the numbers of foveolar and neck mucous cells present in the sample.

Animals↗
PubMed1983

Esterase cytochemistry in primary myelodysplastic syndromes and megaloblastic anaemias: demonstration of abnormal staining patterns associated with dysmyelopoiesis.

Acid alpha naphthyl acetate esterase (ANAE) and combined ANAE-chloroacetate esterase cytochemistry was performed on 121 bone marrow aspirates from primary myelodysplastic syndromes (MDS) and a secondary dysplasia-megaloblastic anaemia (MA). The investigation demonstrated the presence of abnormal ANAE positive granulocyte populations in a significant proportion of cases. These cells, in which the staining patterns were characterized by atypical granular ANAE positivity and double ANAE-chloroacetate reactions, were shown immunologically to lack the receptor and antigenic characteristics of monocytes and morphologically to be granulocytes. Isoelectric focusing, however, indicated that the atypical esterase cytochemistry of these granulocytes was due to the presence of markedly increased concentrations of ANAE isoenzymes usually found in monocytes. Atypical ANAE-staining granulocytes were particularly evident in MDS marrows showing sideroblastic erythroid changes, whilst in MA they were mainly seen in cases of intermediate severity. It is suggested that these cells are associated with dysmyelopoietic changes in both malignant and non-malignant conditions.

Anemia↗
PubMed1996

Esterase isoenzyme profiles of 255 leukemia-lymphoma cell lines from all hematopoietic cell lineages.

Carboxylic esterase isoenzymes isolated from a panel of well-characterized continuous human leukemia-lymphoma cell lines were separated by isoelectric focusing. Typical isoenzyme patterns designated Mono 1/Mono 2 (for monocyte-associated), My 1/My 2 (for myeloid or myeloma), Lym 1/Lym 2 (for lymphoid) and Und (for undifferentiated) could be reproducibly discerned. The Mono patterns contained one unique isoenzyme encoded by the monocyte-specific esterase gene. This comparative analysis of 255 leukemia-lymphoma cell lines covered the major cell lineage that are affected by hematological neoplasias. The results showed that (except for myelomas) lymphoid-derived malignancies, both leukemias and lymphomas, expressed primarily the Und and Lym esterase isoenzyme profiles. In contrast, myeloid leukemia cells and the related erythroid and megakaryocytic cell lines displayed mainly the My patterns. The Mono patterns were detected predominantly in monocyte-derived leukemias. As the B-lymphocytic hierarchy progresses from pre B-cells via B-cells to plasma cells, number and intensity of the isoenzymes increased as well from the Und pattern to the My isoenzyme profile. Hodgkin's disease and anaplastic large cell lymphoma lines displayed heterogenous isoenzyme profiles consistent with their heterogenous cellular origin. The present study using continuous leukemia-lymphoma cell lines as model systems provides a biochemical characterization of different hematopoietic cell lineages and stages of differentiation.

Carboxylesterase↗
PubMed1995

Different isoenzyme patterns of nonspecific esterases and the level of IL6 production as markers of macrophage functions.

We examined the isoenzyme patterns of alpha and beta naphtyl acetate esterase and the IL6 production of two macrophage cell lines, which were cloned from a single fusion of macrophage tumor cells and spleen adherent cells. These clones were phenotypically indistinguishable but differ functionally as line 59 presents antigen to Th 1 lymphocytes while line 63 induces suppressor T lymphocytes. Cell extracts of these lines exhibit different isoenzyme patterns of alpha and beta naphtyl acetate esterase at both pH 7.5 and 5.8 but do not differ significantly in the level of produced IL6. Treatment with nitrogranulogen (NG), a derivative of cyclophosphamide, changes the isoenzyme pattern in line 59 and decreases severalfold IL6 production, while in similarly treated line 63 cells isoenzyme pattern remains unaffected but the production of IL6 is significantly increases. We assume that the observed differences between these two cell lines are due to distinct intracellular translation of the membrane signal delivered by NG. The different behaviour of these two parameters can thus be used as a useful tool to further delineate different macrophage subpopulations. We regard it likely that nonspecific esterases may play a role in intracellular processing or trafficking of antigen.

Animals↗