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 effect of diisopropyl fluorophosphate (DFP), a potent cholinesterase (ChE) inhibitor, on loading quin 2 acetoxymethyl ester (quin 2/AM) and fura 2/AM into smooth muscle cells isolated from guinea pig taenia coli was investigated spectrofluorometrically. The presence of DFP during the loading permitted the incorporation of quin 2 into the cells, so that it became possible to measure intracellular Ca2+ concentrations using the ester of this dye. Also, DFP significantly enhanced the incorporation of fura 2 into the cells. These results indicate that loading of quin 2/AM and fura 2/AM into the smooth muscle cells may depend on the suppression of ChE or various serine protease activities outside cells.
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PMID:Effect of DFP on loading of fura 2/AM and quin 2/AM into single smooth muscle cells prepared from guinea pig taenia coli. 360 23

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.
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PMID:Serum esterase activity in reactive systemic amyloidosis and its relation to amyloid A degrading activity. 609 1

The interaction of serine protease (esterases) with 6-chloro-2-pyrones was investigated. Time-dependent inactivation of chymotrypsin, alpha-lytic protease, pig liver elastase, and cholinesterase was found with 3- and 5-benzyl-6-chloro-2-pyrone, as well as 3- and 5-methyl-6-chloro-2-pyrone. No inactivation was observed with the unsubstituted 6-chloro-2-pyrone. The substituted pyrones did not inactivate papain or carboxypeptidase A, as well as a number of other nonproteolytic enzymes. The substituted chloropyrones, therefore, show considerable selectivity toward serine proteases. Analogues in which the 6-chloro substituent is replaced by H or OH do not inactivate. The presence of the halogen is, therefore, essential for inactivation. Chymotrypsin catalyzes the hydrolysis of 3-benzyl-6-chloro-2-pyrone. At pH 7.5, (E)-4-benzyl-2-pentenedioic acid is the major product, and 2-benzyl-2-pentenedioic anhydride is a minor product. The ration of hydrolysis product found to the number of enzyme molecules inactivated varies from 14 to 40. The enzyme inactivated with the 3-benzyl compound does not show a spectrum characteristic of the pyrone ring. This suggests that inactivation by 3-benzyl-6-chloro-2-pyrone occurs in a mechanism-based fashion after enzymatic lactone hydrolysis. When the enzyme is inactivated with the 5-benzyl compound, absorbance due to the pyrone ring is observed. We suggest that inactivation occurs through an active site directed mechanism involving a 1,6-conjugate addition of an active site nucleophile to the pyrone ring.
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PMID:Novel inactivators of serine proteases based on 6-chloro-2-pyrone. 641 Nov 20

Purified human serum butyrylcholinesterase, which exhibits cholinesterase, aryl acylamidase, and peptidase activities, was cross-reacted with two different monoclonal antibodies raised against human serum butyrylcholinesterase. All three activities were immunoprecipitable at different dilutions of the two monoclonal antibodies. At the highest concentration of the antibodies used, nearly 100% of all three activities were precipitated, and could be recovered to 90-95% in the immunoprecipitate. The peptidase activity exhibited by the purified butyrylcholinesterase was further characterized using both Phe-Leu and Leu-enkephalin as substrates. The pH optimum of the peptidase was in the range of 7.5-9.5 and the divalent cations Co2+, Mn2+, and Zn2+ stimulated its activity. EDTA and other metal complexing agents inhibited its activity. Thiol agents and -SH group modifiers had no effect. The serine protease inhibitors, diisopropylfluorophosphate and phenyl methyl sulfonyl fluoride, did not inhibit. When histidine residues in the enzyme were modified by diethylpyrocarbonate, the peptidase activity was not affected, but the stimulatory effect of Co2+, Mn2+, and Zn2+ disappeared, suggesting the involvement of histidine residues in metal ion binding. These general characteristics of the peptidase activity were also exhibited by a 50 kD fragment obtained by limited alpha-chymotrypsin digestion of purified butyrylcholinesterase. Under all assay conditions, the peptidase released the two amino acids, leucine and phenylalanine, from the carboxy terminus of Leu-enkephalin as verified by paper chromatography and HPLC analysis. The results suggested that the peptidase behaved like a serine, cysteine, thiol-independent metallopeptidase.
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PMID:The peptidase activity of human serum butyrylcholinesterase: studies using monoclonal antibodies and characterization of the peptidase. 842 27

Ghrelin circulates as acylated (AG) and unacylated (or desacyl) ghrelin (UAG). We aimed at clarifying the effect of age and sex on plasma deacylation and degradation of AG in vivo and in vitro in the rat. In vivo, we compared AG and UAG concentrations following administration of 1 microg AG intraperitoneally in rat neonates during the first 3h of life. AG administration caused a 2-3 times increase in plasma AG concentrations contrasting with a approximately 1000 times increase in UAG concentrations suggesting rapid deacylation of AG into UAG. In vitro, we demonstrated that AG degradation was greater in the fetus (97% over 30 min) and decreased progressively to 57% in adult animals (P<0.001). Carboxylesterase and butyrylcholinesterase activities were determined during the fetal (day 21 of pregnancy) and postnatal period (days 1, 6, 13, 21 and 28) and in the adult rat and were found to increase with age (P<0.001). While inhibition of carboxylesterase and butyrylcholinesterase did not affect AG deacylation, serine protease inhibitors decreased AG degradation in the adult rat (from 59% to 23%) and, to a lesser extent, in the rat neonate (from 92% to 57%) by reducing both deacylation and degradation into non-UAG metabolites. Our data suggest that degradation of AG into UAG and non-UAG metabolites is much faster in the fetus and in the rat neonate compared to the adult. We speculate that this process allows for fine tuning of the physiological effects of both AG and UAG.
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PMID:Ontogeny of acylated ghrelin degradation in the rat. 1994 28

The tobacco cutworm, Spodoptera litura, is an important pest of crop and vegetable plants worldwide, and its resistance to insecticides have quickly developed. However, the resistance mechanisms of this pest are still unclear. In this study, the change in mRNA and miRNA profiles in the susceptible, indoxacarb-resistant and field indoxacarb-resistant strains of S. litura were characterized. Nine hundred and ten co-up-regulated and 737 co-down-regulated genes were identified in the resistant strains. Further analysis showed that 126 co-differentially expressed genes (co-DEGs) (cytochrome P450, carboxy/cholinesterase, glutathione S-transferase, ATP-binding cassette transporter, UDP-glucuronosyl transferase, aminopeptidase N, sialin, serine protease and cuticle protein) may play important roles in indoxacarb resistance in S. litura. In addition, a total of 91 known and 52 novel miRNAs were identified, and 10 miRNAs were co-differentially expressed in the resistant strains of S. litura. Furthermore, 10 co-differentially expressed miRNAs (co-DEmiRNAs) had predicted co-DEGs according to the expected miRNA-mRNA negative regulation pattern and 37 indoxacarb resistance-related co-DEGs were predicted to be the target genes. These results not only broadened our understanding of molecular mechanisms of insecticide resistance by revealing complicated profiles, but also provide important clues for further study on the mechanisms of miRNAs involved in indoxacarb resistance in S. litura.
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PMID:A systemic study of indoxacarb resistance in Spodoptera litura revealed complex expression profiles and regulatory mechanism. 3162 65