Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The optimal reaction conditions and kinetic properties of eleven leukocyte acid hydrolases determined with the use of fluorigenic derivatives of 4-methyl-umbelliferone are described. The enzymes studied were acid phosphatase, aryl sulfatase, alpha- and beta-glucosidase, alpha- and beta-galactosidase, alpha-mannosidase, N-acetyl-beta-glucosaminidase, N-acetyl-beta-galactosaminidase, beta-glucuronidase and alpha-fucosidase. More than 90% of the activity of each enzyme was released into a 27,000 X g supernatant by a double sonication procedure employing 0.9% sodium chloride and 0.1% Triton X-100. The Km values obtained were similar to those previously reported for chromogenic subtrates. A single Km value could not be derived for beta-galactosidase because its double reciprocal plot was not linear. All enzymes could be measured with less than 10 mug of protein within 15 min. Activators and inhibitors studied included the chloride salts of Na+, K+, Zn2+, Ca2+, Mg2+, Hg2+, and Fe2+ as well as p-chloromercuriphenysulfonate, glutathione, BAL, EDTA, EGTA, Triton X-100 and sodium taurocholate. The reaction conditions described in this report can be used for the diagnosis of various lysosomal storage diseases and should facilitate the development of automated procedures for the analysis of these eleven enzyme activities with small quantities of blood.
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PMID:Human leukocyte acid hydrolases: characterization of eleven lysosomal enzymes and study of reaction conditions for their automated analysis. 0 26

Protoplast fusion, induced by polyethylene glycol and Ca2+, was carried out between two auxotrophic strains of Aspergillus niger. The fusion frequency ranged from 6.2 x 10(-2) - 9.1 x 10(-2). After induced haploidization of a diploid, various segregants showing combinations of the parental genetic markers were isolated. Unlike diploids, haploid segregants exhibited greater variations in their morphology and beta-glucosidase activities. One segregant showed a 2.5-fold increase in beta-glucosidase activity over those of the parents. Thus, this method appears promising for creating new recombinant strains of A. niger with improved beta-glucosidase activities.
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PMID:Protoplast fusion of beta-glucosidase-producing Aspergillus niger strains. 128 15

Sexual development in Dictyostelium discoideum has many unique features making it an attractive eukaryotic model system for the study of biomembrane fusion and intercellular communication. The work presented here provides primary biochemical evidence for two distinct phases during early sexual development that appear to be defined by calcium-dependent gamete cell fusion. In addition, we introduce a novel procedure for the enrichment of zygote giant cells and use this method to define certain wheat-germ agglutinin binding glycoproteins which are specifically located in zygote giant cells and others which are markers for surrounding amoebae in the second phase of development. In addition, a G protein which is present in high amounts early in development is unique to giant cells in the second phase, suggesting a role in phagocytosis. Finally, alkaline phosphatase activity was found to mark the first phase of sexual development, suggesting a role in cell fusion. This contrasts with the patterns of alpha-mannosidase and beta-glucosidase activity that increase late in the second developmental phase, where they likely function in endocyte digestion during the cytophagic period. The developmental significance of these findings is discussed.
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PMID:Zygote giant cell differentiation in Dictyostelium discoideum: biochemical markers of specific stages of sexual development. 129 42

The effects of dietary fat and dietary fiber (DF) levels in diet on fecal flora, activities of three fecal enzymes, putrefactive metabolites, fecal mutagenicity and fecal properties were studied in eight healthy volunteers. They were given low fat and low DF diet (LF: fat energy ratio was 13.9%, and DF intake was 9.0 g/day) for 10 days, high fat and low DF diet (HF: fat energy ratio was 52.7%, and DF intake was 7.1 g/day) for 10 days, and high fat and high DF diet (HFF: fat energy ratio was 52.0%, and DF intake was 24.8 g/day) for 10 days. No change of fecal flora at the bacterial group level was observed throughout the experimental period, except that the population of lactobacilli showed a tendency to increase in HF period. Fecal activities of beta-glucuronidase, beta-glucosidase and nitroreductase and some putrefactive products were unchanged between LF and HF, while these values decreased in HFF period. No significant change of fecal properties was observed between LF and HF, while by HFF supplementation fecal weight increased and fecal pH value was lower than that in LF and HF. Excretions of iron, zinc and calcium in feces did not increase by high DF supplementation.
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PMID:Effect of dietary fat and fiber on fecal flora, bacterial metabolites, and fecal properties in Japanese volunteers. 133 9

Effects of corn fiber residue (5 g/day for 10 days) on fecal weight, moisture, pH, fecal flora, ammonia content, and on the activities of beta-glucuronidase and beta-glucosidase were investigated in six healthy subjects. Corn fiber residue was remnant of hemicellulose extraction from corn fiber by calcium hydroxide. Fecal weight showed a tendency to increase, and fecal pH did not change during corn fiber residue supplementation. No remarkable changes in the fecal flora at the bacterial group level were observed. Fecal ammonia content and beta-glucuronidase activity per gram of wet feces decreased slightly but the daily output did not change. Fecal beta-glucosidase activities per gram of wet feces increased significantly (p less than 0.05) and the daily output also tended to increase during corn fiber residue supplementation.
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PMID:Effect of corn fiber residue supplementation on fecal properties, flora, ammonia, and bacterial enzyme activities in healthy humans. 165 31

Using Percoll density gradient centrifugation after treatment of the postnuclear supernatant (PNS) with 1 mM Ca2+ to swell and lighten mitochondria, we isolated highly purified lysosomes (dextranosomes) in high yield (25%) from the livers of rats to which dextran had been administered. The lysosomal fraction obtained by this method was enriched more than 100-fold in N-acetyl-beta-glucosaminidase and arylsulfatase and 40-fold in acid phosphatase and beta-glucosidase. Electron microscopic examination and measurement of marker enzyme activity for various subcellular organella indicated that the lysosomal fraction was essentially free from contamination by other organella. Flavins, ubiquinones, and hemochromes were found on lysosomal membranes and investigated. The FAD and ubiquinone-9 contents of the purified lysosomal membranes were 0.118 and 6.93 nmol/mg of protein, respectively. Hemochromes in lysosomes showed spectra similar to that of a b-type cytochrome, with the alpha-peak at 562 nm and the gamma-peak at 436 nm.
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PMID:Isolation of highly purified lysosomes from rat liver: identification of electron carrier components on lysosomal membranes. 166 46

Electrophoretic data revealed the presence of various isozymes of endoglucanase and beta-glucosidase, the number of which varied from one to three in various species of the genus Aspergillus. pH 5.0 was optimum for all the isozymes whereas metal ion treatment showed complete inhibition of almost all the isozymes by Hg2+ and partial inhibition by Ca2+ and Co2+ of isozymes of both the enzymes. An alteration in the electrophoretic mobility of isozymes of beta-glucosidase was also noticed in some species with Hg2+ treatment.
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PMID:Physical characterization of isozymes of endo-beta-1,4-glucanase and beta-1,4-glucosidase from Aspergillus species. 204 45

Two enzymes that hydrolysed lactose were purified essentially to homogeneity from cell extracts of the oleaginous yeast Trichosporon cutaneum. One enzyme of Mr 120,000 had properties typical of a beta-galactosidase (EC 3.2.1.23). It hydrolysed lactose, lactulose and nitrophenyl-beta-D-galactosides. The enzyme required K+ or Rb+ for activity, and other monovalent cations tested were not effective. Enzyme activity was abolished by EDTA and stimulated by Mg2+, Mn2+ and Ca2+. The beta-galactosidase was induced by lactose, galactose, lactulose and lactobionic acid. The other enzyme, a beta-glycosidase (EC 3.2.1.21) of Mr 52,000 showed no ionic requirements and it hydrolysed lactose, nitrophenyl-beta-D-galactosides, 4-nitrophenyl-beta-D-glucoside, cellobiose, laminaribiose, laminaritriose and sophorose, but not gentiobiose, 4-nitrophenyl-beta-D-mannoside or sucrose. This enzyme was induced by lactose, galactose and lactulose, and also by cellobiose.
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PMID:Purification and properties of two lactose hydrolases from Trichosporon cutaneum. 212 10

The metabolism of calcium hopantenate (HOPA) was studied in beagle dogs. After oral administration of 14C-labeled HOPA, 25.5% of the administered radioactivity was excreted in the urine within 24 hr, mostly in the form of unchanged drug. The only metabolite, accounting for 4.2% of the radioactivity in the urine, was isolated by HPLC. The metabolite was hydrolyzed by the treatment of beta-glucuronidase (Helix pomatia), acid phosphatase, or beta-glucosidase. These enzyme activities were not inhibited by treatment with D-glucaric acid 1,4-lactone or PO4(3-), but with D-gluconic acid 1,5-lactone, demonstrating that the metabolite is a glucose conjugate. The compound was identified as HOPA-glucoside, 4'-O-(beta-D-glucopyranosyl)-D-hopantenic acid, by GC/MS analyses after derivatization of the metabolite and the synthetic compound. This is the first reported instance of glucose conjugation to a non-acidic hydroxyl group in the metabolism of xenobiotics in mammals.
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PMID:Hopantenic acid beta-glucoside as a new urinary metabolite of calcium hopantenate in dogs. 287 36

A facile isolation of beta-glucosidase (EC 3.2.1.21) from Escherichia coli containing the recombinant plasmid pNZ1001 carrying a beta-glucosidase gene from the extremely thermophilic anaerobic bacterium Tp8 is reported. The enzyme was purified to homogeneity by anion-exchange chromatography and steric exclusion HPLC following thermal denaturation/precipitation of heat-labile E. coli proteins. The enzyme had a broad specificity for beta-D-glucosides, galactosides, fucosides, and xylosides. Action on aryl-beta-D-glycosides of glucose, galactose, and fucose was characterized by low Km and high Kcat/Km values compared with disaccharide substrates for which specificity decreased in the order laminaribiose, sophorose, cellobiose, beta-gentiobiose, lactose. Galactono-1-4-lactone, glucono-1-5-lactone, and 1-O-methyl-beta-D-glucose were competitive inhibitors with Ki values of 1.6, 0.09, and 17.5 mM, respectively. The enzyme was remarkably stable to detergents, urea, and organic solvents. Thermostability was greatest at the pH activity optimum (pH 6.0-6.5) and half-life (t1/2) values were 11 min at 90 degrees C, 105 min at 85 degrees C, and 900 min at 80 degrees C. Activity was destabilized by Sr2+, Co2+, Ca2+, Mg2+, and Mn2+, but t1/2 increased in the presence of substrates or competitive inhibitors. Activation energy, Ea, was 54.3 kJ.mol-1. A free thiol group(s) was required for full activity, this being rapidly lost in the presence of Hg2+ or N-ethyl maleimide.
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PMID:Stability and substrate specificity of a beta-glucosidase from the thermophilic bacterium Tp8 cloned into Escherichia coli. 312 75


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