Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studied was the effect of beta-glucuronidase, hydrocortisone, and mercaptoethanol in bull semen on the activity of the alkaline phosphatase and the viability and fertilizing capacity of spermatozoa. It was found that the beta-glucuronidase enzyme in conc. of 270 UI per cu. cm of semen enhanced the activity of one of the forms of AP in agar electrophoresis (AP-1) with the simultaneous enhancement of the thermal resistance of spermatozoa at 46 degrees C and their fertilizing capacity by 9.6 per cent at first insemination. At minimum concentration hydrocortisone (1 X 10(-6) M) lowered the heat resistance of spermatozoa at 39 degrees C. Mercaptoethanol was found to lower by 3 per cent the activity of semen alkaline phosphatase. It is suggested to use the beta-glucuronidase enzyme in the practice of artificial insemination out of all other biologically active agents studied.
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PMID:[Effect of biologically active substances on the alkaline phosphatase activity, viability and fertility of bull spermatozoa]. 688 16

Human red blood cell (RBC) membranes have been reported to contain both high and low affinity 'forms' of the drug metabolizing enzyme thiol methyltransferase (TMT). The biochemical characteristics of the two 'forms' of human RBC TMT were compared. Apparent Km constants of the high affinity activity for 2-mercaptoethanol and S-adenosyl-L-methionine, cosubstrates for the TMT reaction, were 0.38 mumol/l and 2.6 mumol/l, respectively. These constants may be compared with values of 20 mmol/l and 43 mumol/l, respectively, previously reported for the low affinity form of RBC TMT activity. The properties and regulation of the two forms of TMT were then compared with each other and also with those of two 'control' enzymes, phenol methyltransferase (PMT) and beta-glucuronidase. When high and low affinity TMT, PMT and beta-glucuronidase activities were measured in RBC membranes from 22 individual subjects, there were highly significant correlations among all three methyltransferase activities (all r values greater than 0.95), but beta-glucuronidase activity did not correlate significantly with any of the methyltransferase activities (all r values less than 0.40). The thermal stabilities of the three methyltransferases were very similar. They were all inactivated approximately 50% by incubation at 48 degrees C for 15 min. beta-Glucuronidase activity was approximately 50% inactivated by incubation at 76 degrees C for 15 min. PMT and both TMT activities had similar subcellular distributions and similar responses to ions and to enzyme inhibitors. These results suggested that high and low affinity TMT and PMT activities might be catalyzed by the same enzyme. Alternatively, these three RBC membrane methyltransferase activities might be regulated in a parallel fashion.
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PMID:Correlation of low and high affinity thiol methyltransferase and phenol methyltransferase activities in human erythrocyte membranes. 688 20

Of all the bioassays to determine acute toxicity described in the literature, those that employ bacteria as indicator organisms are usually the most rapid and the most economic, although alone they cannot predict the possible toxic effect of any type of substance. When bioassays are employed to test the toxicity of known substances and of compounds in samples from waste discharges they have to work in very different conditions from those for which they are designed. The effects of three factors, pH, buffer concentration, and NaCl, on the performance of a fluorogenic bioassay based on the beta-glucuronidase activity of Escherichia coli were investigated. The results of this test were compared with those of two known biluminescent bacteria tests. The fluorogenic bioassay has a more restricted optimum pH range, while the influence of buffer concentration was similar for the three tests. E. coli glucuronidase activity was affected at a concentration as low as 128 mg/l of NaCl. Changes in the pH or buffer concentrations or chloride ions, greatly influenced the respectives toxicities of four substances, acridine orange, TEMED, 2-mercaptoethanol, and mercuric chloride.
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PMID:A trial to compare the effects of pH, buffer concentration, and NaCl, on one fluorescent and two bioluminescent bacterial tests for acute toxicity. 956 62

A method to quantify metabolites of 17beta-nandrolone (17betaN) in boar and horse urine has been optimized and validated. Metabolites excreted in free form were extracted at pH 9.5 with tert-butylmethylether. The aqueous phases were applied to Sep Pak C18 cartridges and conjugated steroids were eluted with methanol. After evaporation to dryness, either enzymatic hydrolysis with beta-glucuronidase from Escherichia coli or solvolysis with a mixture of ethylacetate:methanol:concentrated sulphuric acid were applied to the extract. Deconjugated steroids were then extracted at alkaline pH with tert-butylmethylether. The dried organic extracts were derivatized with MSTFA:NH4I:2-mercaptoethanol to obtain the TMS derivatives, and were subjected to analysis by gas chromatography mass spectrometry (GC/MS). The procedure was validated in boar and horse urine for the following metabolites: norandrosterone, noretiocholanolone, norepiandrosterone, 5beta-estran-3alpha, 17beta-diol, 5alpha-estran-3beta, 17beta-diol, 5alpha-estran-3beta, 17alpha-diol, 17alpha-nandrolone, 17betaN, 5(10)-estrene-3alpha, 17alpha-diol, 17alpha-estradiol and 17beta-estradiol in the different metabolic fractions. Extraction recoveries were higher than 90% for all analytes in the free fraction, and better than 80% in the glucuronide and sulphate fractions, except for 17alpha-estradiol in the glucuronide fraction (74%), and 5alpha-estran-3beta, 17alpha-diol and 17betaN in the sulphate fraction (close to 70%). Limits of quantitation ranged from 0.05 to 2.1 ng mL(-1) in the free fraction, from 0.3 to 1.7 ng mL(-1) in the glucuronide fraction, and from 0.2 to 2.6 ng mL(-1) in the sulphate fraction. Intra- and inter-assay values for precision, measured as relative standard deviation, and accuracy, measured as relative standard error, were below 15% for most of the analytes and below 25%, for the rest of analytes. The method was applied to the analysis of urine samples collected after administration of 17betaN laureate to boars and horses, and its suitability for the quantitation of the metabolites in the three fractions has been demonstrated.
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PMID:Quantitation of 17beta-nandrolone metabolites in boar and horse urine by gas chromatography-mass spectrometry. 1738 11