Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A procedure is described for the preparation of extensively purified beta-D-glucosidase (EC 3.2.1.21) from the cytosol fraction of rat kidney. The specific activity of the beta-glucosidase in the high speed supernatant (100 000 X g, 90 min) fraction of rat kidney homogenate is 700-fold greater than that in the same fraction from heart, skeletal muscle, lung, spleen, brain or liver. beta-Glucosidase activity co-chromatographs with beta-D-galactosidase, beta-D-fucosidase, alpha-L-arabinosidase and beta-D-xylosidase activities through the last four column steps of the purification and their specific activities are 0.26, 0.39, 0.028 and 0.017 relative to that of beta-glucosidase, respectively. The specific activity of the apparently homogeneous beta-glucosidase is 115 000 nmol of glucose released from 4-methylumbelliferyl-beta-D-glucopyranoside per mg protein per h. All five glycosidase activities possess similar pH dependency (pH optimum, 6--7) and heat lability, and co-migrate on polyacrylamide disc gels at pH 8.9 (RF, 0.67). beta-Glucosidase acitivity is inhibited competitively by glucono-(1 leads to 5)-lactone (KI, 0.61 mM) and non-competitively by a variety of sulfhydryl reagents including N-ethylmaleimide, p-chloromercuribenzoate, 5,5'-dithio-bis(2-nitrobenzoic acid), and iodoacetic acid. Although the enzyme will release glucose from p-nitrophenyl and 4-methylumbelliferyl derivatives of beta-D-glucose, it will not hydrolyze xylosyl-O-serine, beta-D-glucocerebroside, lactose, galactosylovalbumin or trehalose. The enzyme consists of a single polypeptide chain with a molecular weight of 50 000--58 000, has a sedimentation coefficient of 4.41 S and contains a relatively large number of acidic amino acids. A study of the distribution of beta-glucosidase activity in various regions of the dissected rat kidney indicates that the enzyme is probably contained in cells of the proximal convoluted tubule. The enzyme is also present in relatively large amounts in the villus cells, but not crypt cells, of the intestine. The physiological substrate and function of the enzyme are unknown.
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PMID:Isolation and characterization of beta-glucosidase from the cytosol of rat kidney cortex. 0 4

We have purified an induced beta-D-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) from Stachybotrys atra to apparent homogeneity. The induced enzyme was clearly different from the constitutive beta-D-glucosidase. The molecular weight was 65 500-69 000, the pH optimum was at 6.7 and the isoelectric point at 4.8. Carbohydrate content (related to glucose) was 14.4%. The enzyme showed beta-D-glucosidase, beta-D-xylosidase and beta-D-thioglucosidase activity. These three activities sppear to be due to the same enzyme. The enzyme was strongly inhibited by D-glucono-(1 leads to 5)-lactone and nojirimycin and was very sensitive to sulfhydryl reagents.
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PMID:Purification and properties of an induced beta-D-glucosidase from stachybotrys atra. 2 63

The common identity of human acidic beta-D-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) and beta-D-xylosidase (1,4-beta-D-xylan xylohydrolase, EC 3.2.1.37) as one enzyme and that of acidic beta-D-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23), beta-D-fucosidase (no allotted EC number) and alpha-L-arabinosidase (alpha-L-arabinofuranoside arabinohydrolase, EC 3.2.1.55) as another enzyme is indicated by similar binding patterns of glycosidase activities of each enzyme to various lectins. by similar ratios between their intra- and extracellular levels in normal and I-cell fibroblasts and by their deficiencies in liver tissues from patients with Gaucher disease and GM1 gangliosidosis, respectively. A third enzyme, neutral beta-D-galactosidase, purified to homogeneity from human liver has been shown to possess all these five glycosidase activities at neutral pH. These neutral enzymic activities were not bound by any of the lectins examined and found to be reduced in liver and spleen of a patient with neutral beta-D-galactosidase deficiency. An additional form of beta-D-xylosidase with optimal activity at pH 7.4 was bound by the fucose-binding lectin from Ulex eurpaeus while no binding was observed for the acidic (pH 4.8) and neutral (pH 7.0) beta-D-xylosidase activities of the multiple glycosidase enzymes.
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PMID:Multiple carbohydrate-cleaving specificities in human acidic and neutral glycosidases. 11 23

1. Peripheral blood serum alpha-D-galactosidase, beta-D-galactosidase, beta-D-glucosidase, alpha-D-mannosidase, beta-D-xylosidase and beta-D-glucuronidase have been studied with a comparative point of view from several mammalian species: Bos taurus L. (bull), Capra hircus L. (goat), Sus scropha var. domestica L. (pig) and man. 2. Fluorimetric and spectrophotometric procedures were used for determination of enzyme activities and pH optima. 3. Glycosidase activity was generally higher with fluorescent substrates than with chromogenic substrates. 4. alpha-D-mannosidase was the most active with both fluorescent and chromogenic substrates. 5. All the studied enzymes had the same pH optimum (4.0) when the chromogenic substrates were used. 6. pH optima of these glycosidases ranged from 3.0 to 5.5 when the fluorescent substrates were used.
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PMID:Comparative studies on six blood serum glycosidases from several mammalian species. 31 97

A beta-D-glucosidase (linamarase) was purified 11,700-fold from the butter bean, Phaseolus lunatus L., by means of successive procedures including extraction, ammonium sulfate fractionation, acetone treatment, and chromatographies on CM-Sephadex, DEAE-Sephadex, and Sephadex G-200. The final preparation gave a single protein band on both disc polyacrylamide gel electrophoresis and SDS-polyacrylamide gel electrophoresis. In spite of its electrophoretic purity, the final enzyme preparation showed four glycosidase activities; beta-D-glucosidase, beta-D-galactosidase, beta-D-fucosidase, and beta-D-xylosidase. The molecular weight of the enzyme was determined to be 124,000 +/- 9,000 by Sephadex G-200 gel filtration, and 59,000 +/- 2,400 by SDS-disc gel electrophoresis. The enzyme showed a pH optimum in the range of 5.1 to 6.0 with p-nitrophenyl beta-D-glucoside, 4-methylumbelliferyl beta-D-glucoside, and linamarin. Among natural substrates containing a beta-glucosyl terminal, linamarin, prunasin, and salicin were hydrolyzed by the enzyme from butter beans, but amygdalin, cellobiose, gentiobiose, and laminarin were hardly hydrolyzed.
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PMID:Purification and properties of beta-D-glucosidase (linamarase) from the butter bean, Phaseolus lunatus. 311 32

Homogenates of Giardia lamblia trophozoites exhibited the following hydrolase activities: acid phosphatase (EC 3.1.3.2), proteinase (EC 3.1.4) with urea-denatured hemoglobin and N-benzoyl-DL-arginine-2-naphthylamide as substrates, deoxyribonuclease (EC 3.1.4.5), and ribonuclease (EC 2.7.7.16). beta-N-Acetylglucosaminidase (EC 3.2.1.30), beta-galactosidase (EC 3.2.1.23), beta-glucuronidase (EC 3.2.1.31), alpha-D-glucosidase (EC 3.2.1.20), beta-D-glucosidase (EC 3.2.1.21), and beta-D-xylosidase (EC 3.2.1.37) activities were below the level of detection. Differential and isopycnic centrifugation of homogenates demonstrated that giardial hydrolases were localized in a single-particle population sedimenting at 7200g for 30 min. The particles had a buoyant density in sucrose of 1.15 and exhibited latency. Latency was completely destroyed by Triton X-100 or 15 cycles of freezing and thawing. After centrifugation of Triton- or freeze-thaw-treated particle fractions, the hydrolase activities, though no longer latent, were still sedimentable suggesting tight binding to the organelle membrane. Latency was destroyed simultaneously for all hydrolases, in direct proportion to the amount of Triton added to a particle preparation or to the number of times a particle preparation was subjected to freezing and thawing. These results support the suggestion that the hydrolases of G. lamblia trophozoites are localized in a single-particle population of lysosome-like organelles.
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PMID:Giardia lamblia: localization of hydrolase activities in lysosome-like organelles of trophozoites. 327 50

The rumen fungi Neocallimastix patriciarum, Piromonas communis, and a morphologically distinct but unidentified isolate were cultivated on the polysaccharides starch, cellulose, xylan, and their principal component monosaccharides and disaccharides, and the range and specific activities of the glycoside hydrolases formed were monitored using gluco-oligosaccharide and p-nitrophenyl glycoside substrates. A wide range of enzyme activities was detected in preparations from vegetative growth and zoospores of all three isolates. Enzyme activity was also present in the culture medium. The specific activities were affected by the carbohydrate source available in the growth medium, although the more active hydrolases involved in the degradation of plant structural and storage polysaccharides were formed on all seven carbohydrate sources evaluated. Enzyme activities were increased in the zoospore, vegetative, and extracellular preparations after growth on the appropriate structurally related disaccharide or polysaccharide. The hemicellulolytic glycosidases (alpha-L-arabinofuranosidase, beta-D-xylosidase) were most active after growth on xylan, whereas alpha-/beta-glucosidase activity was increased with the corresponding glucan as growth substrate. However, whereas wide-ranging beta-glucosidase activity was detected following growth on maltose or starch, the alpha-glucosidase activities of P. communis were lower or undetectable in vegetative preparations grown on glucose or the beta-glucans cellobiose and cellulose.
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PMID:Glycoside hydrolase enzymes present in the zoospore and vegetative growth stages of the rumen fungi Neocallimastix patriciarum, Piromonas communis, and an unidentified isolate, grown on a range of carbohydrates. 360 11

Homogeneous (as judged by data from gel filtration, ultracentrifugation, polyacrylamide gel electrophoresis with and without sodium dodecyl sulfate (SDS), and isoelectric focusing) beta-xylosidase showing beta-D-xylosidase, beta-D-glucosidase, beta-D-galactosidase, and alpha-L-arabinosidase activities has been isolated from the hemicellulase preparation of the microscopic fungus Aspergillus niger 15 by ethanol fractionation and chromatography on Sephadex G-50, cellulose DE-52, and Sephadexes SP C-50 and G-200. The specific activity of the enzyme toward p-nitrophenyl-beta-D-xylopyranoside (p-NPX) increased 199-fold and was equal to 35.2 units/mg of protein; the activity yield was 43%. The sedimentation coefficient was equal to 10.6 S, and the molecular weight was 253,000 according to the gel filtration data and 122,000 according to the data from SDS electrophoresis. The isoelectric point was at pH 4.9. An amino acid analysis has shown that dicarboxylic and hydrophobic amino acids prevail in the enzyme. beta-Xylosidase had no carbohydrate component, and p-chloromercuribenzoate inhibited its activity. The temperature optimum of beta-xylosidase activity toward p-NPX was at 70 degrees C, and the pH optimum was 3.8-4.0. The enzyme was stable at pH 3 to 8 and did not lose its activity for 1 h at temperatures up to 50 degrees C. D-Xylose was found to be a competitive inhibitor of the beta-D-xylosidase activity of the enzyme with Ki = 2.9 mM. beta-Xylosidase showed transglycosylase activity.
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PMID:beta-Xylosidase from Aspergillus niger 15: purification and properties. 643 8

An electrophoretic system using cellulose acetate has been developed for the resolution of beta-glucosidase isozymes (beta-D-glucoside glucohydrolase, EC 3.2.1.21 and D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45) in human tissue homogenates. Electrophoresis of homogenates from normal and Type 1 Gaucher disease tissues revealed two fluorescent bands of beta-glucosidase activity which corresponded to the acid and neutral isozymes separated by concanavalin A-Sepharose chromatography. The acid isozyme has only beta-glucosidase activity, whereas the neutral isozyme also exhibited alpha-L-arabinosidase (alpha-L-arabinofuranoside arabinofuranohydrolase, EC 3.2.1.55), beta-D-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) and beta-D-xylosidase (1,4-beta-D-xylan xylohydrolase, EC 3.2.1.37) activities, using the appropriate 4-methylumbelliferyl glycoside. In homogenates of cultured skin fibroblasts, only the acid isozyme was observed which co-electrophoresed with the acidic activity in other tissue homogenates. The acidic activity in tissue and fibroblast homogenates from Type 1 Gaucher disease appeared to co-electrophorese with the acid isozyme in normal tissues, but had markedly reduced activity.
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PMID:Electrophoretic separation of neutral and acid beta-glucosidase isozymes in human tissues. 677 81

Gene libraries ("zoolibraries") were constructed in Escherichia coli using DNA isolated from the mixed liquor of thermophilic, anaerobic digesters, which were in continuous operation with lignocellulosic feedstocks for over 10 years. Clones expressing cellulase and xylosidase were readily recovered from these libraries. Four clones that hydrolyzed carboxymethylcellulose and methylumbelliferyl-beta-D-cellobiopyranoside were characterized. All four cellulases exhibited temperature optima (60-65 degrees C) and pH optima (pH 6-7) in accordance with conditions of the enrichment. The DNA sequence of the insert in one clone (plasmid pFGH1) was determined. This plasmid encoded an endoglucanase (celA) and part of a putative beta-glucosidase (celB), both of which were distinctly different from all previously reported homologues. CelA protein shared limited homology with members of the A3 subfamily of cellulases, being similar to endoglucanase C from Clostridium thermocellum (40% identity). The N-terminal part of CelB protein was most similar to beta-glucosidase from Pseudomonas fluorescens subsp. cellulosa (28% homology). The use of zoolibraries constructed from natural or laboratory enrichment cultures offers the potential to discover many new enzymes for biotechnological applications.
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PMID:Direct isolation of functional genes encoding cellulases from the microbial consortia in a thermophilic, anaerobic digester maintained on lignocellulose. 754 4


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