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

Forty male guinea pigs were exposed to nitrogen dioxide in a concentration of 2 mg/m3, 8 hours daily for a period of 180 days. Forty male animals were used as a control group. The following changes were found in intoxicated animals: the decrease of total protein and seromucoid concentration in blood serum and the decrease of total protein, perchloric acid-soluble proteins, protein-bound hexosamines and sialic acids content, in liver tissue. Electrophoretic examination of the serum proteins showed the increase of alpha 1- and beta 2-globulins and the decrease of albumin concentration. Changes in the level of glycoproteins fractions and protein-bound carbohydrates in blood serum were described also. Estimation of enzymes activity showed the decrease of alanine and aspartate transaminase activity in blood serum caused by the strong decrease of the cytoplasmic fraction of these enzymes. However the simultaneous increase of the mitochondrial fraction of transaminases activity was observed. The decrease of the activity of choline esterase was found also. Similar changes of enzymes activity were found in liver tissue. Histopathological studies were done for the further clearing the influenze of nitrogen dioxide on serum and liver proteins concentration and enzymes activity. It was found that after long-term exposure to nitrogen dioxide the destruction processes may be observed in the liver. The possible mechanism of the nitrogen dioxide-induced damage of protein metabolism is discussed.
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PMID:Studies on the effect of long-term exposure to nitrogen dioxide on serum and liver proteins level and enzyme activity in guinea pigs. 100 97

The activities of aspartate transminase (EC 2.6.1.1), alanine transminase (EC 2.6.1.2), alkaline phosphatase (EC 3.1.3.1), acid phosphatase (EC 3.1.3.2) leucine arylamidase (EC 3.4.1.1), aldolase (EC 4.1.2), lactate dehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.38) and cholinesterase (EC 3.1.1.7) were measured in serum of male rabbits and albino Wistar rats in dlplicate by means of microliter techniques. Furthermore, the diurnal alterations of enzyme activity were established in 8--10 animals of both species. Aspartate transaminase activity in the serum of rats was found to be significantly higher than in the serum of humans and rabbits, and essentially lower alkaline phosphatase values were obtained from the serum of rabbits in comparison with those found for the serum of humans and rats. Relatively high acid phosphatase and aldolase values as well as a very low cholinesterase activity were found in the serum of rabbits and rats. The mean malate dehydrogenase-activity was found to be twice as high as the mean lactate dehydrogenase, which is the contrary of the situation found in human serum. No significant diural alterations of the examined enzyme activities were established. The differences found between the animal and the human enzyme activities in serum are explained by species-determined peculiarities of metabolism or specific enzyme configuration.
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PMID:[Enzyme activities in serum of rabbits and rats-reference values and circadian alterations. Serum enzymes and factors that influence their activity,I (AUTHOR'S TRANSL)]. 103 68

Following 25 mug/day synthetic alpha-MSH administration, the liver regeneration of partially hepatectomized rats proved to be increased. The hormone treatment resulted in an enhanced alanine incorporation of the liver proteins, but this effect was uncertain on partially hepatectomized rats. Due to the hormone treatment the low liver protein content of the operated rats became normal. The pseudocholinesterase activity of the liver homogenate of alpha-MSH treated rats was also elevated. On the basis of these experiments authors are supposing some protein synthesis increasing effect of synthetic alpha-MSH.
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PMID:The effect of alpha-melanophor-stimulating hormone on liver regeneration and incorporation of amino acid in rats' liver protein. 122 18

The aim of the study was to evaluate the suitability of enzymatic tests for estimating the effects of organic solvents upon the organisms of daily exposed workers. The analysis was undertaken in 572 workers exposed to such solvents as toluene, xylene, cresols and benzine. Periodical examination was carried out for the purposes of the study. The level of excreting organic solvents' metabolites in urine and serum enzymes' activity were determined. Also, the activity of alanine and aspartate aminotransferases and of plasmatic cholinesterase was determined. The results of the study support the necessity of applying the enzymatic tests as a basic method of evaluating the toxic activity of organic solvents.
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PMID:[Evaluation of the usefulness of enzyme tests for the diagnosis of the effects of various organic solvents in the conditions of occupational exposure]. 143 46

Evidence for the involvement of Ser-203, His-447, and Glu-334 in the catalytic triad of human acetylcholinesterase was provided by substitution of these amino acids by alanine residues. Of 20 amino acid positions mutated so far in human acetylcholinesterase (AChE), these three were unique in abolishing detectable enzymatic activity (less than 0.0003 of wild type), yet allowing proper production, folding, and secretion. This is the first biochemical evidence for the involvement of a glutamate in a hydrolase triad (Schrag, J.D., Li, Y., Wu, M., and Cygler, M. (1991) Nature 351, 761-764), supporting the x-ray crystal structure data of the Torpedo californica acetylcholinesterase (Sussman, J.L., Harel, M., Frolow, F., Oefner, C., Goldman, A., Toker, L. and Silman, I. (1991) Science 253, 872-879). Attempts to convert the AChE triad into a Cys-His-Glu or Ser-His-Asp configuration by site-directed mutagenesis did not yield effective AChE activity. Another type of substitution, that of Asp-74 by Gly or Asn, generated an active enzyme with increased resistance to succinylcholine and dibucaine; thus mimicking in an AChE molecule the phenotype of the atypical butyrylcholinesterase natural variant (D70G mutation). Mutations of other carboxylic residues Glu-84, Asp-95, Asp-333, and Asp-349, all conserved among cholinesterases, did not result in detectable alteration in the recombinant AChE, although polypeptide productivity of the D95N mutant was considerably lower. In contrast, complete absence of secreted human AChE polypeptide was observed when Asp-175 or Asp-404 were substituted by Asn. These two aspartates are conserved in the entire cholinesterase/thyroglobulin family and appear to play a role in generating and/or maintaining the folded state of the polypeptide. The x-ray structure of the Torpedo acetylcholinesterase supports this assumption by revealing the participation of these residues in salt bridges between neighboring secondary structure elements.
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PMID:Mutagenesis of human acetylcholinesterase. Identification of residues involved in catalytic activity and in polypeptide folding. 151 12

Genomic DNA from two families exhibiting the K-variant phenotype of serum butyrylcholinesterase was amplified by PCR and sequenced to determine the molecular basis of this variant. The K-variant phenotype was found to be associated with a DNA transition from guanine to adenine at nucleotide 1615, which caused an amino acid change from alanine 539 to threonine (GCA----ACA; Ala539----Thr). There was a 30% reduction of serum butyrylcholinesterase activity associated with this mutation. Amplification and sequencing of DNA from a random sample of 47 unrelated people gave a frequency of .128 for the K-variant allele. Thus, 1 person in 63 should be homozygous for the K-variant, making the K-variant the most common butyrylcholinesterase variant. The K-variant mutation was also found to be present in 17 (89%) of 19 butyrylcholinesterase genes containing the point mutation which causes the atypical phenotype of butyrylcholinesterase (GAT----GGT; Asp70----Gly). The presence of the K-variant in the same molecule as the atypical variant does not contribute to the qualitative change in the atypical enzyme, but it most likely accounts for the approximately one-third reduction in Vmax of butyrylcholinesterase activity in atypical serum. Two additional point mutations located in noncoding regions of the gene were also observed to be in linkage disequilibrium with the K-variant mutation. As many as four different point mutations have been identified within a single butyrylcholinesterase gene. Inhibition tests of the enzyme in plasma are usually used to distinguish the K-variant from the usual enzyme when the former is present with the heterozygous atypical variant (AK phenotype vs. UA phenotype). Inhibition tests were performed on plasma enzyme from the four possible genotypic combinations of the heterozygous atypical mutation with or without the K-variant mutation on either allele; we found that the AK phenotype was caused by three genotypes (A/K, AK/K, and U/A) and that the UA phenotype was caused by two genotypes (U/A and U/AK).
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PMID:DNA mutation associated with the human butyrylcholinesterase K-variant and its linkage to the atypical variant mutation and other polymorphic sites. 157 Aug 38

The distribution of amino acids between plasma, liver and brain was studied in adult male rats, fed a diet containing 8.7, 17 (control animals), 32 and 51% of protein during 15 days. The caloric intake was nearly equal in all groups. The highest food intake was observed in the animals on the low protein diet. Changes in plasma amino acids were variable. In contrast to the behavior of most amino acids in plasma, the branched chain amino acids were highest in the animals fed the 51% protein diet. Despite the low protein intake in the animals fed a 8.7% protein diet, the concentration of serine, glutamic acid, glutamine, glycine, alanine, methionine, isoleucine, leucine, phenylalanine and ornithine were significantly higher compared to control animals, whereas in those receiving a high protein diet, valine, leucine, tyrosine, tryptophan and histidine increased in relation to the increased protein and amino acid intake. The plasma amino acid patterns are not greatly influenced by the amino acid distribution in the food and the amount ingested. Alanine aminotransferase, aspartate aminotransferase, glutamate dehydrogenase and cholinesterase showed a two- to fivefold increased activity in the liver of animals consuming a high protein diet. In the brain, the concentration of valine, leucine, isoleucine, phenylalanine and tyrosine in animals receiving the low protein diet was higher than in controls and increased further with increasing protein content of the diet. Glutamine was increased in all dietary groups. The predicted influx of amino acids showed increasing influx rates in dependence of the plasma amino acid concentration. The entry of tyrosine and tryptophan and their brain concentration was inversely proportional to the protein content of the diet. In the present study which considers long-term adaptation to an increasing protein and amino acid intake in comparison to a balanced control protein diet, the levels of the indispensable amino acids were maintained within narrow limits in the brain and liver. The results indicate that inspite of a variable protein intake, the body tends to keep organ amino acids in relatively narrow limits favoring in this way amino acid homeostasis.
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PMID:Effect of different protein diets on the distribution of amino acids in plasma, liver and brain in the rat. 159 Jun 69

Serum CA 19-9 and alpha-fetoprotein (AFP) levels were determined in 211 patients with liver cirrhosis and 27 with primary hepatocellular carcinoma (HCC) associated with liver cirrhosis. This was done to determine the usefulness of CA 19-9 level with respect to AFP level in distinguishing between these two illnesses, and to assess the influence of some clinical and biochemical variables on these tests in patients with liver cirrhosis with or without primary HCC. Pathologic AFP values were found in 23 of 27 (sensitivity, 85%) patients with HCC; CA 19-9 levels increased in only 12 of 27 (sensitivity, 44%) HCC patients, the values being comparable with those of patients with liver cirrhosis. In liver cirrhosis a substantial number of false-positive values was found for both markers, although they were higher for CA 19-9 (50 of 211 versus 39 of 211). In liver cirrhosis correlations were found between AFP level and alanine amino-transferase level; and between CA 19-9 level and (1) total bilirubin value, (2) alkaline phosphatase level, and (3) pseudocholinesterase level. The authors conclude that CA 19-9 level is a poor biochemical marker, inferior to AFP level, in the detection of a carcinomatous transformation of liver cirrhosis. The finding of false-positive AFP values in liver cirrhosis seems mainly attributable to cellular proliferation and necrosis. Cholestasis seems to greatly affect serum CA 19-9 level variations, probably by reducing its liver metabolism.
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PMID:Serum CA 19-9 and alpha-fetoprotein levels in primary hepatocellular carcinoma and liver cirrhosis. 138 Dec 71

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


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