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)

In 30 workers being occupationally exposed to beryllium, examinations of biochemical indicators of liver efficiency were carried out: activity of alanine and asparagine aminotraspherase and basic phosphatases, cholinesterase, content of total protein and its fraction. Levels of electrolytes were determined: calcium, potassium, phosphorus, and magnesium. The above examinations were also carried out on 30 persons who have no contact with beryllium. The obtained results were subjected to statistical analysis. In 10 persons from the group exposed to beryllium one found lowering of the level of magnesium in blood serum, whereas in the control group the level of this electrolyte was correct in all persons. As to the results on the level of magnesium, in both groups high statistical significance was found (p less than 0,01). A dependence was found between the amount of workers and the lowered level of magnesium in blood serum and the duration of occupational exposure to beryllium. The comparison of the remaining results of examinations of both groups did not reveal any statistically significant differences or the differences were at the point of statistical significance.
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PMID:[Behavior of various biochemical indices of liver efficiency and of selected blood serum electrolytes in workers exposed to beryllium]. 19 75

The effect of organic and inorganic forms of nitrogen on biomass accumulation and cholinesterase synthesis was studied with Arthrobacter simplex var. cholinesterasus. The culture assimilates nitrogen of ammonium compounds better than other forms of inorganic nitrogen; the best nitrogen source for biosynthesis of cholinesterase is ammonium phosphate. Nitrogen of nitrates is not assimilated. The amount of biomass is almost twice as high on the medium with peptone, casein or casein hydrolysate as on the medium with mineral nitrogen, while the activity of cholinesterase on these nitrogen sources decreases 1.5--2.0 times. Yeast extract as a nitrogen source increases biomass accumulation by a factor of 2.5 and does not supress synthesis of cholinesterase. The concentration of the enzyme synthesized per unit biomass on the medium with yeast extract is the same as on the medium containing ammonium phosphate. The effect of amino acids and amides, i.e. beta-alanine, proline, amides of aspartic and glutamic acids, and their mixtures, is similar to the action of yeast extract: they stimulate biomass accumulation and do not inhibit synthesis of the enzyme. Other amino acids supress synthesis of cholinesterase. The amount of accumulated biomass in the presence of glutamic acid is twice as high as in the case of any other amino acid, and three times as high as on the medium containing ammonium phosphate. Similar action of glutamic acid is manifested when it is used in mixtures with other amino acids. On the medium containing glutamic acid as a sole source of nitrogen, an increase in biomass production is accompanied with a decrease in biosynthesis of the enzyme by 50%. Repression of the biosynthesis is less if glutamic acid is added in mixtures with proline, beta-alanine and asparagine.
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PMID:[Effect of nitrogen source on growth of Arthrobacter simplex and its biosynthesis of cholinesterase]. 97 79

Acetylcholinesterases (EC 3.1.1.7, AChE) have varying amounts of carbohydrates attached to the core protein. Sequence analysis of the known primary structures gives evidence for several asparagine-linked carbohydrates. From the differences in molecular mass determined on sodium dodecyl sulfate-polyacrylamide gel before and after deglycosylation with N-glycosidase F (EC 3.2.2.18), it is seen that dimeric AChE from red cell membranes is more heavily glycosylated than the tetrameric brain enzyme. Furthermore, dimeric and tetrameric forms of bovine AChE are more heavily glycosylated than the corresponding human enzymes. Monoclonal antibodies 2E6, 1H11, and 2G8 raised against detergent-soluble AChE from electric organs of Torpedo nacline timilei as well as Elec-39 raised against AChE from Electrophorus electricus cross-reacted with AChE from bovine and human brain but not with AChE from erythrocytes. Treatment of the enzyme with N-glycosidase F abolished binding of monoclonal antibodies, suggesting that the epitope, or part of it, consists of N-linked carbohydrates. Analysis of N-acetylglucosamine sugars revealed the presence of N-acetylglucosamine in all forms of cholinesterases investigated, giving evidence for N-linked glycosylation. On the other hand, N-acetylgalactosamine was not found in AChE from human and bovine brain or in butyrylcholinesterase (EC 3.1.1.8) from human serum, indicating that these forms of cholinesterase did not contain O-linked carbohydrates. Despite the notion that within one species, the different forms of AChE arise from one gene by different splicing, our present results show that dimeric erythrocyte and tetrameric brain AChE must undergo different postsynthetic modifications leading to differences in their glycosylation patterns.
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PMID:Different glycosylation in acetylcholinesterases from mammalian brain and erythrocytes. 154 61

Drosophila acetylcholinesterase (EC 3.1.1.7) is a 150-kDa glycoprotein anchored in plasmic membranes via a glycolipid. It is composed of two active subunits which are themselves made of two noncovalently linked polypeptides of 18 and 55 kDa resulting from the proteolysis of a single precursor of 75 kDa. Active Drosophila acetylcholinesterase can be expressed in Xenopus oocytes as an excreted protein. We have identified some of the amino acids essential in post-translational modifications of the protein by site-directed mutagenesis and expression of mutants in this system. The intersubunit disulfide bond involves cysteine at position 615. Cleavage of the 75-kDa precursor, as observed in Drosophila, originates from a hydrophilic peptide (in position 148 to 180) which does not exist in cholinesterase sequences from vertebrates. This cleavage is associated with excretion out of the cell. Drosophila acetylcholinesterase exhibits four effective sites of asparagine-linked glycosylation in positions 126, 174, 331, and 531. We show that glycosylations and dimerization protect the protein against proteolytic digestion. In contrast, none of these post-translational modifications significantly affects the activity of acetylcholinesterase or affinity for its substrate.
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PMID:Post-translational modifications of Drosophila acetylcholinesterase. In vitro mutagenesis and expression in Xenopus oocytes. 173 Jul 12

The structure and some functional sites of human milk bile salt activated lipase (BAL) were studied by cDNA cloning and chemical analysis of the enzyme. Eighteen cDNA clones of human BAL were identified from lactating human breast cDNA libraries in lambda gt11 and lambda gt10 with antibody and synthetic oligonucleotides as probes. The sequence of four clones was sufficient to construct a 3018-bp BAL cDNA structure. This sequence codes for an open reading frame of 742 amino acid residues. There is a putative signal sequence of 20 residues which is followed by the amino-terminal sequence of BAL, and the mature BAL contains 722 amino acid residues. The cDNA sequence also contains a 678-base 5'-untranslated sequence, a 97-base 3'-untranslated region, and a 14-base poly(A) tail. The sequence of a 1.8-kbp insert of clone G10-4A differs from that of the other cDNA in that it contains a deletion of 198 bases (1966-2163) corresponding to 66 amino acid residues. By use of BAL cDNA as probe, it was found that the major molecular species of BAL mRNA in human mammary gland HBL-100 cells had a size of 2.9 kb and two minor species had sizes of 3.8 and 5.1 kb by Northern blot analyses. The deduced BAL protein structure contains in the carboxyl-terminal region 16 repeating units of 11 amino acids each. The repeating units have the basic structure Pro-Val-Pro-Pro-Thr-Gly-Asp-Ser-Gly-Ala-Pro with only minor substitutions. The amino acid sequence of human BAL is related to that of pancreatic lysophospholipase, cholesterol esterase, cholinesterase, acetylcholinesterase, and thyroglobulin. Ten of the 14 cyanogen bromide fragments of diisopropyl fluorophosphate inhibited human milk BAL were isolated, determined for N-terminal sequences, analyzed for amino sugars, and tested for some functional properties. These chemical studies established that the active site of human milk BAL is located at serine-194, the N-glycosylation site is present at asparagine-187, the O-glycosylation region is in the 16 repeating units near the C-terminus, and the heparin binding domain is in the N-terminal region. We have also determined the location of disulfide bridges as Cys64-Cys80 and Cys246-Cys257. The cyanogen bromide cleavage and the partial sequencing of CNBr peptides also confirmed the location of methionines in the polypeptide chain as well as the deduced cDNA sequence of BAL.
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PMID:Structure of human milk bile salt activated lipase. 198 41

The present investigation revealed the effect of the organochlorine insecticide dieldrin at the dose level 0.25 LD50 at different time intervals on the concentration of 11 rat brain amino acids, on the activities of glutamic oxyacetic transaminase (GOT), glutamic pyruvic transaminase (GpT) and cholinesterase. The study was also extended to include the total protein content during the tested periods. The daily injection of dieldrin caused a marked decrease in the levels of glutamic acid, glutamine and taurine and an increase in the levels of aspartic acid, asparagine, GABA, glycine, lysine, serine, alanine and histidine. However, the maximal increase and decrease were recorded for most of the tested amino acids at the end of the tested period. The activity of the transaminases increased significantly. The recorded values of GOT were usually higher than GPT. Cholinesterase activity was inhibited thoroughly during all the experimental periods. Total protein content was decreased in the experiment; the minimal value was given 3 days after the injection.
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PMID:Effect of dieldrin injection on the level of certain amino acids and some enzymes in rat brain. 287 4

This study was aimed to examine whether disulfiram (DS) may exacerbate the pre-existing liver damage induced by D-galactosamine (GalN) in rats. DS, 600 mg/kg, administered by gavage for 3 days caused an increase in asparagine aminotransferase (AspAT) and alkaline phosphatase (AP) and a decrease in cholinesterase (ChE) activity in the serum and decrease in AspAT and ChE activity in the liver. DS given to rats with GAlN-induced liver injury caused significant increase in alanine aminotransferase (A1AT) and bilirubin level in serum in comparison with rats with GalN-damaged liver but without DS treatment. In summary, DS exacerbates a damage of the liver of rats. This study supported the clinical observations showing enhanced liver damage in alcoholics treated with DS.
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PMID:Effect of disulfiram on function of the liver of rats with galactosamine-induced hepatitis. 309 1

The combined enzymological investigation including determination of the total activity of asparagine transaminase and alanine transaminase, two serum enzymes, alkaline phosphatase, gamma-glutamyl transpeptidase, acetyl cholinesterase, and butyryl cholinesterase was applied to two groups of pregnant women with pyelonephritis treated with ampicillin (12 patients) and roscillin (14 patients). The investigation was performed at the following stages: before the treatment, on the 7th and on the 12th day of the treatment. No statistically significant differences in the average values of the activity of the above enzymes at these stages were observed in patients of the both groups which indicated the absence of the hepatotoxic effect of the preparations on the patients of a group as a whole. An increase in the levels of transaminases recorded in some patients after discontinuation of the treatment course was evident of a possible cytotoxic effect of the drugs without the signs of cholestasis. The effect was connected with the initial functional renal insufficiency.
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PMID:[Enzymological evaluation of the hepatotoxicity of ampicillin and its therapeutic form, roscillin, in the treatment of pyelonephritis in pregnancy]. 399 43

The use of metronidazole in radiation therapy of laryngeal cancer (SFD = 20 Gy) as a radiosensitizer of tumor hypoxic cells resulted in changes of the liver function tests: a decrease in the cholinesterase activity, a decrease in the level of cholesterol and albumin esters in the blood serum that characterize synthetic liver function. Similar though more noticeable in amounts shifts were marked in stomach cancer patients following preoperative irradiation (SFD = 20 Gy). A slight decrease in AP activity and a decrease in LDH activity below the initial level were simultaneously noted in the latter group as opposed to the group of laryngeal cancer patients. The deviations from the initial level of such liver function indices as bilirubin and total protein level, alanine and asparagine aminotransferase activity did not depend on the incorporation of metronidazole in the radiotherapeutic scheme and developed one way in the intervention and control groups of patients disregarding tumor site. The comparison of shifts of the liver tests in stomach and laryngeal cancer patients in whom tumor site was responsible for the incorporation of the liver in the irradiated zone or for the distance from it, made it possible to regard MZ direct toxic effect and its radiosensitizing effect on the hepatic tissue as causes of the observed deviations.
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PMID:[State of the liver after radiotherapy of cancer of the stomach and larynx with metronidazole radiosensitization]. 651 53

Workers exposed to naphtha, tungsten, vanadium, cobalt and titanium exhibited decreased activity of asparagine and alanine aminotransferase, cholinesterase and ceruloplasmin in blood serum, as compared to controls. Activity of lactic acid dehydrogenase was not changed significantly. It might be surmised that absorption of metals and naphtha exhibits inhibitory properties in relation to the enzymes determined.
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PMID:[Effect of low concentrations of metals and benzin on serum enzyme activity]. 666 96


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