Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.8 (cholinesterase)
12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The spontaneously hypertensive rat (SHR)--animal model for human essential hypertension--develops a generalized arteriopathy. The present paper discusses the atherogenic influence of hypertensive arterial lesions. The following changes in the intima might influence its permeability and barrier function, increase the trapping effect and stimulate the smooth muscle cell proliferation: the hyper-reactivity of endothelial cells; the decreased thickness of endothelial cell periphery; the reduced intercellular junction pathways; the increase in basal lamina and glycosaminoglycan sub-endothelial material; the mononuclear cell infiltrations; the widened fenestrae in the internal elastic lamina. Some hypertensive changes of the tunica media may also interact with atherogenic process through reduced smooth muscle cell lipolytic capabilities, slowed transmural diffusion, perturbed efflux, aggravated media hypoxia, namely: the decrease in esterase and cholinesterase activities, the activations of some lysosomal enzymes, the increase in collagen, glycosaminoglycan and elastin content; the increased media thickness and transmural passage; the modified smooth muscle cell behavior.
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PMID:[Hypertensive arteriopathy and atherogenesis: cellular and molecular interactions]. 310 95

Sialate 9(4)-O-acetylesterases (EC 3.1.1.53) have been isolated from equine liver, bovine brain and influenza C virus. In this latter case, the esterase represents the receptor-destroying enzyme of the virus. The kinetic properties of these enzymes were determined with Neu5,9Ac2 and in part with 4-methylumbelliferyl acetate and Neu5,9Ac2-lactose. The Km values vary between 0.13 and 24 mM and the Vmax values from 0.55 to 11 U/mg of protein. The pH optima are in the range of 7.4-8.5, the molecular masses at 56,500 and 88,000 Da. In addition to a fast hydrolysis found for aromatic acetates, such as 4-methylumbelliferyl acetate or 4-nitrophenyl acetate, N-acetyl-9-O-acetylneuraminic acid is de-O-acetylated at the highest relative rate. Other substituents at the 9-position, such as lactoyl residues, or acetyl groups at other positions within the side chain are not hydrolyzed. Neu4,5Ac2, however, is a substrate for all 3 enzymes. The hydrolysis rates of this ester function, which renders sialic acids resistant to the action of sialidases, vary from 3 to 100% relative to Neu5,9Ac2. Whereas Neu5,9Ac2-lactose is hydrolyzed by the bovine and viral esterases, other O-acetylated sialic acids in glycoconjugates are only attacked by the enzyme from influenza C virus and not by that from bovine brain. The esterase from horse liver also releases 4-O-acetyl groups from equine submandibular gland mucin. By incubation with appropriate substrates and inhibition studies, carboxylesterase, amidase and choline esterase activities were excluded, as well as the cleavage of other acyls, e.g., butyryl groups. Thus, the enzymes investigated belong to the acetylesterases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sialate O-acetylesterases: key enzymes in sialic acid catabolism. 314 20

The 60-kDa esterase was isolated from liver microsomes of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced rabbits and its complete amino acid sequence determined. Automated sequence analysis of intact protein, as well as characterization of the peptides obtained from enzymatic and chemical cleavages, led to the elucidation of the primary structure. The protein is a single polypeptide consisting of 539 residues and molecular weight 59,478. The active site serine is 195, and another diisopropylphospho binding site is at histidyl 441. Carbohydrate chains are attached at aspariginyl residues 61 and 363. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment induces this esterase severalfold, the amino acid sequence of the induced enzyme is identical to that of the enzyme isolated from liver microsomes of untreated rabbits. The sequence of the microsomal esterase is 30% identical with the sequences of human serum cholinesterase and the acetylcholinesterase from Torpedo californica. There is also a close homology between the 60-kDa esterase and the COOH-terminal domain of bovine thyroglobulin.
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PMID:Complete covalent structure of 60-kDa esterase isolated from 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced rabbit liver microsomes. 334 53

In an acute study, albino rats of both sexes were orally administered graded doses of Pirimiphosmethyl, and the statistically computed median lethal dose (LD-50) were 1861 and 1667 mg/kg body weight for male and female rats respectively. No treatment related changes were discernible with regard to food intake, growth, gross or histopathology of the organs. In a time-course study, the correlation between symptoms and degree of esterase inhibition was examined in rats administered the minimum lethal dose (MLD: 1000 mg/kg b.w.) of the insecticide. Time-course inhibition pattern of both cholinesterase (ChE) and non-specific carboxylesterase (NSE) activities in brain and plasma revealed maximum inhibition at 24 h post-treatment which correlated well with the intensity of symptoms. In a subacute study, groups of male rats were fed dietary Pirimiphos-methyl at 0, 10, 250, 500 and 1000 ppm for 28 days. Food consumption and growth rate were not affected throughout the experimental period. At necropsy after 28 days, no gross pathological changes were seen in any of the organs except a slight increase in liver weight at 1000 ppm. Though no statistical differences were observed in the levels of hepatic transaminases, a significant increase in serum transaminase was evident. Significant increase in the activities of hepatic ALP, beta-GLR and serum ALP were evident at 500 and 1000 ppm. Further, significant inhibition of plasma PChE was evident at 250, 500 and 1000 ppm while the degree of inhibition of brain AChE was significant only at the higher dosages. No histopathological alterations were observed in any of the organs.
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PMID:Toxicity of pirimiphos-methyl: I. The acute and subacute oral toxicity in albino rats. 338 33

Tetrahydroaminoacridine (THA) has been reported to improve the memory of persons with Alzheimer's disease, but its mechanism of action is uncertain. We found that clinically effective concentrations, 0.03-0.3 microM, readily inhibit acetylcholinesterase and butyrylcholinesterase from rabbit hippocampal tissue in artificial cerebrospinal fluid (CSF) at 37 degrees C with physiological levels of substrate Above 1 microM, THA was found to act at primary and allosteric sites on M1 and M2 muscarine receptors as an antagonist. This is not clinically important, and low levels of THA do not improve the binding of the agonist, oxotremorine-M. Only 10-1000 microM THA has been shown to block K+ channels. Thus THA probably acts as an esterase inhibitor.
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PMID:Effects of tetrahydroaminoacridine on M1 and M2 muscarine receptors. 338 74

Plasma aspirin esterase activity and cholinesterase activity were reduced in patients with aspirin sensitive asthma and aspirin sensitive urticaria compared to asthmatic and dermatological controls. Phenylacetate (non specific) esterase activities, were however unaltered in these patients. The reason for the lower activity is uncertain but it does not appear to be due to genetically determined lower cholinesterase or due to the avoidance of aspirin by sensitive patients. A low aspirin esterase activity may be a contributory factor in precipitating these aspirin sensitive reactions.
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PMID:Plasma esterase activity in patients with aspirin-sensitive asthma or urticaria. 344 44

The identity of a peptidase activity with human serum pseudocholinesterase (PsChE) purified to apparent homogeneity was demonstrated by co-elution of both peptidase and PsChE activities from procainamide-Sepharose and concanavalin-A--Sepharose affinity chromatographic columns; comigration on polyacrylamide gel electrophoresis; co-elution on Sephadex G-200 gel filtration and coprecipitation at different dilutions of an antibody raised against purified PsChE. The purified enzyme showed a single protein band on gel electrophoresis under non-denaturing conditions. SDS gel electrophoresis under reducing conditions, followed by silver staining, also gave a single protein band (Mr approximately equal to 90,000). Peptidase activity using different peptides showed the release of C-terminal amino acids. Blocking the carboxy terminal by an amide or ester group did not prevent the hydrolysis of peptides. There was no evidence for release of N-terminal amino acids. Potent anionic or esterase site inhibitors of PsChE, such as eserine sulphate, neostigmine, procainamide, ethopropazine, imipramine, diisopropylfluorophosphate, tetra-isopropylpyrophosphoramide and phenyl boronic acid, did not inhibit the peptidase activity. An anionic site inhibitor (neostigmine or eserine) in combination with an esterase site inhibitor (diisopropylfluorophosphate) also did not inhibit the peptidase. However, the choline esters (acetylcholine, butyrylcholine, propionylcholine, benzoylcholine and succinylcholine) markedly inhibited the peptidase activity in parallel to PsChE. Choline alone or in combination with acetate, butyrate, propionate, benzoate or succinate did not significantly inhibit the peptidase activity. It appeared that inhibitor compounds which bind to both the anionic and esteratic sites simultaneously (like the substrate analogues choline esters) could inhibit the peptidase activity possibly through conformational changes affecting a peptidase domain.
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PMID:A peptidase activity exhibited by human serum pseudocholinesterase. 354 20

The histological, ultrastructural, morphometrical and histochemical aspects of the arterial media were studied in young and aged SHR, and compared to normotensive Wistar Kyoto rats. The diffuse thickening was the most characteristic feature of the hypertensive media. It seems due to three processes: Early generalized hypertrophy of smooth muscle cells (smc); connective matrix neogenesis and smc proliferation, more evident in peripheral vasculature. The present paper discusses the following hypertensive tunica media changes in relation to the atherosclerotic process: the decrease in lipolytic esterase and cholinesterase activities; the activation of some lysosomal enzymes; the increase in collagen, glycosaminoglycan and elastin content; the increased media thickness; the modified smc behavior (migration, secretion, proliferation). These alterations might positively influence arterial susceptibility to atherosclerosis through reduced smc lipolytic activity; slowed transmural diffusion; perturbed efflux and aggravated media hypoxia.
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PMID:Tunica media changes in the spontaneously hypertensive rat (SHR). 360 28

The carboxylesterase activity in both plasma and liver of guinea-pig were separated into three main peaks by chromatofocusing. Two of the three plasma enzymes were retained by affinity chromatography on Affi-Gel Blue (100-200 mesh). Isoelectric points determined by chromatofocusing or isoelectrofocusing were pI 6.1, pI 5.2 and pI 4.0 for the plasma enzymes, and pI 5.7, pI 5.2 and pI 4.5 for the liver enzymes. The effect of selective esterase inhibitors, soman, physostigmine (cholinesterase inhibitor) and bis-4-nitrophenyl phosphate (carboxylesterase inhibitor), suggested that the three enzymes in both tissues may be regarded as carboxylesterases. However, the pI 5.7 carboxylesterase was partially inhibited by physostigmine, and the pI 4.5 carboxylesterase was almost not affected by bis-4-nitrophenyl phosphate. The ratio between the activities towards 4-nitrophenyl butyrate and methyl butyrate differed among the carboxylesterases in both tissues. All three carboxylesterases in plasma were partially reactivated by diacetylmonoxime after soman inhibition in vitro, but to a different extent. The soman inhibited liver carboxylesterases were not reactivated by diacetylmonoxime.
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PMID:Carboxylesterases in guinea-pig plasma and liver. Tissue specific reactivation by diacetylmonoxime after soman inhibition in vitro. 368 30

Indices of acute and delayed toxicity following administration of triorthotolyl phosphate (TOTP) were measured in roosters from lines of chickens originating from the Cornell randombred population. Matings were designed to produce individuals that had presence or absence of allele 21 of the B blood system. Non-B21 individuals had allele 13 or 31. Acute inhibition of esterases (neurotoxic esterase, liver cholinesterase, plasma cholinesterases, and plasma carboxylesterases) occurred in all birds within 24 hr of a single oral dose of 360 mg/kg TOTP. Clinical signs of delayed neuropathy were evident within 12 days of TOTP administration, with no significant difference between genotypes. Dietary deoxycorticosterone (40 to 200 ppm) appeared incapable of statistically significant modification of the strong effects of TOTP. Activities of blood esterases were different between roosters having B21/B21 and those with B13 and/or B31.
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PMID:Neurotoxicity of triorthotolyl phosphate in chickens of different genotypes in the presence and absence of deoxycorticosterone. 370 83


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