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)

An enzyme extract from Cellulase-Onozuka, a commercial product of Trichoderma viride, was fractionated by Amberlite CG-50 column chromatography into three cellulase [EC 3.2.1.4] groups, peaks I to III. A noval enzyme, which has both beta-glucosidase [EC 3.2.1.21] and exo-carboxymethyl-cellulase (exo-CMCase) properties was obtained from peak III by extensive purification throuh consecutive column chromatography. The enzyme was homogeneous on ultracentrifugation, SDS-gel and cellulose acetate film electrophoreses and molecular sieve chromatography on Bio-Gel P-150. The molecular weight of this enzyme was estimated to be 53,000. The enzyme appeared to release cellobiose residues one by one from the nonreducing end of higher cellooligosaccharides and CM-cellulose (CMC), but to release glucosyl residues from reduced cellotriose and beta-cellobioside, resembling a beta-glucosidase in this respect. Furthermore, this exo-CMCase also attacked xylan exo-wise to produce xylobiose moleculaes one by one, but it scarcely attacked insoluble cellulose, except for a cellodextrin apparently rich in amorphous structure.
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PMID:Purification and properties of an exo-cellulase component of novel type from Trichoderma miride. 0 9

beta-Glucosidase [beta-D-glucoside glucohydrolase EC 3.2.1.21] and beta-galactosidase [beta-D-galactoside galactohydrolase, EC 3.2.1.23] of Takadiastase were purified by acetone fractionation, DEAE-cellulose, and hydroxylapatite chromatography. Purity was confirmed by disc electrophoresis, ultracentrifugation and measurement of other glycosidase activities which coexisted in Takadiastase. Molecular weight of the beta-glucosidase was 218,000 by sedimentation equilibrium and 110,000-116,000 by SDS-disc electrophoresis. Molecular weight of the beta-galactosidase was 112,000 by sedimentation and 56,000-59,000 by SDS-disc electrophoresis. These values showed that both enzymes consisted of two subunits. Taka-beta-N-acetylglucosaminidase also consisted of two subunits. Both enzymes were glycoproteins containing glucosamine and neutral sugar. Stability, pH optima, isoelectric points, and some specificities were observed.
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PMID:Comparative studies of three exo-beta-glycosidases of Aspergillus oryzae. 3 73

Piromyces sp. strain E2, an anaerobic fungus isolated from an Indian elephant (hindgut fermenter) was tested for its ability to ferment a range of substrates. The fungus was able to use bagasse, cellobiose, cellulose, fructose, glucose, lactose, mannose, starch, wheat bran, wheat straw, xylan and xylose. Formate and acetate were the main fermentation products after growth on these substrates. The amount of carbon found in the fermentation products of cultures, in which substrate digestion was complete averaged 88.5 mM, or 59% of the carbon offered as substrate. No growth was observed on other substrates tested. Lactose, starch, cellobiose and filter paper cellulose were good inducers of cellulolytic and xylanolytic enzymes. Cellulolytic and xylanolytic enzymes were produced constitutively by Piromyces strain E2, although enzyme activities were generally lower after growth on glucose and other soluble sugars. Complex substrates (bagasse, wheat bran, and wheat straw) were good inducers for xylanolytic enzymes but not for cellulolytic enzymes. The extracellular protein banding pattern after SDS-PAGE was therefore only slightly affected by the growth substrate. Identical beta-glucosidase and endoglucanase activity patterns were found after growth on different substrates. This indicated that differences in enzyme activities were not the result of secretion of different sets of isoenzymes although it remains possible that the relative amount of each isoenzyme produced is influenced by the growth substrate.
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PMID:Production of cellulolytic and xylanolytic enzymes during growth of the anaerobic fungus Piromyces sp. on different substrates. 152 5

Although beta-D-fucosidase (beta-D-fucoside fucohydrolase, EC 3.2.1.38) has been isolated from various sources, the identity of this enzyme is still not settled. We have purified a specific beta-D-fucosidase in electrophoretically homogeneous form crude extracts of Aspergillus phoenicis by polyethyleneglycol 6000-phosphate buffer aqueous two-phase separation, and successive chromatography on DEAE-Sephadex A-50, hydroxyapatite and Sephadex G-100 columns. The molecular weight of the enzyme was estimated to be 57000 by SDS-polyacrylamide gel electrophoresis and 50000 to 60000 by gel filtration on Sephadex G-100. The enzyme showed optimum coside were 2.4mmol/L, and 1.28 mumol min-1 the pH range 5.5-6.5 and below 35 degrees C. The Km and the Vmax values for pNP-beta-D-fucoside were 2.4mmol/L, and 1.28 mumol.min-1.mg-1 respectively. The enzyme was strongly inhibited by sulfhydryl group reagents, PCMB-NEM and iodoacetate. It was also inhibited by EDC, DEP and NBS. Thus, -SH, -COOH groups, histidyl and tryptophyl residues were essential for enzyme activity. The purified beta-D-fucosidase showed high specificity toward p-nitrophenyl beta-D-fucoside. The enzyme was inhibited by D-fucose and D-fucono-gamma-lactone, but not by D-galactose, D-galactono-gamma-lactone, D-glucose or D-glucono-gamma-lactone; the latter compounds are specific inhibitors of beta-D-galactosidase and beta-D-glucosidase respectively. Thus, this enzyme is the most strictly specific beta-D-fucosidase when compared with those previously reported.
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PMID:[Studies on the beta-D-fucosidase from Aspergillus phoenicis]. 159 57

A major beta-glucosidase I and a minor beta-glucosidase II were purified from culture filtrates of the fungus Trichoderma reesei grown on wheat straw. The enzymes were purified using CM-Sepharose CL-6B cation-exchange and DEAE Bio-Gel A anion-exchange chromatography steps, followed by Sephadex G-75 gel filtration. The isolated enzymes were homogeneous in SDS-polyacrylamide gel electrophoresis and isoelectric focusing. beta-Glucosidase I (71 kDa) was isoelectric at pH 8.7 and contained 0.12% carbohydrate; beta-glucosidase II (114 kDa) was isoelectric at pH 4.8 and contained 9.0% carbohydrate. Both enzymes catalyzed the hydrolysis of cellobiose and p-nitrophenyl-beta-D-glucoside (pNPG). The Km and kcat/Km values for cellobiose were 2.10 mM, 2.45.10(4) s-1 M-1 (beta-glucosidase I) and 11.1 mM, 1.68.10(3) s-1 M-1 (beta-glucosidase II). With pNPG as substrate the Km and kcat/Km values were 182 microM, 7.93.10(5) s-1 M-1 (beta-glucosidase I) and 135 microM, 1.02.10(6) s-1 M-1 (beta-glucosidase II). The temperature optimum was 65-70 degrees C for beta-glucosidase I and 60 degrees C for beta-glucosidase II, the pH optimum was 4.6 and 4.0, respectively. Several inhibitors were tested for their action on both enzymes. beta-Glucosidase I and II were competitively inhibited by desoxynojirimycin, gluconolactone and glucose.
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PMID:Purification and characterization of two extracellular beta-glucosidases from Trichoderma reesei. 159 51

Maize beta-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) was incubated in the presence of SDS concentrations varying from 0.025 to 3.2% at two different pHs (5 and 8), electrophoresed through 10% SDS-polyacrylamide gels, and stained for activity. The zymogram patterns of SDS-treated samples were similar to those of untreated (control) samples. The same samples were also analyzed by native PAGE and IEF, yielding similar patterns for controls and for SDS-treated samples. However, zymogram patterns were severely distorted on IEF gels when SDS concentration of the sample medium was at or above 1.6%. These results suggest that the beta-glucosidase monomer (a 60 kD polypeptide) is either catalytically active or it re-forms dimers upon the removal of SDS during equilibration washes, since the in vivo form of the functional enzyme is thought to be a dimer. The activity of maize beta-glucosidase on SDS-gels after SDS-PAGE does not seem to be limited to this enzyme alone, because beta-glucosidases from other sources (e.g., almond, Trichoderma, and Penicillium) were also active on SDS-gels. Enzyme activity in the presence of SDS or after SDS treatment may be more common than one would expect on the basis of the conventional biochemical dictum that ionic detergents denature and inactivate enzymes. Enzyme activity in the presence of SDS and development of zymograms on SDS-gels offer new approaches to studies of enzyme structure and activity.
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PMID:Detection of beta-glucosidase activity on sodium dodecyl sulphate-polyacrylamide gels. 175 85

Prosaposin is the precursor protein for saposins, which are small lysosomal proteins required for the hydrolysis of sphingolipids by specific lysosomal hydrolases. Prosaposin, in addition to generating the saposins in the lysosomes, also exists as an unprocessed approximately 70-kDa protein in many tissues and secretory fluids. In this study, we isolated prosaposin from human milk. Milk was fractioned by ammonium sulfate precipitation, then chromatographed with DEAE-Sephacel and G-3000 SW gel permeation-HPLC. A fraction containing prosaposin was finally purified with the anti-saposin C IgG attached affinity column. The protein staining of the purified preparation on SDS-PAGE and the Western blotting showed a single band. The sequence of the initial 10 amino acids from N-terminus of the purified protein was identical to the sequence of prosaposin deduced from cDNA. Although prosaposin itself showed beta-glucosidase activator activity at a slight degree, the activity increased much after trypsin treatment. Western blotting of the trypsin-treated sample confirmed the formation of small saposin-like bands from prosaposin by the action of trypsin.
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PMID:Isolation and characterization of prosaposin from human milk. 195 98

A beta-D-glycosidase activity was purified from mycelium of Humicola grisea var. thermoidea grown on avicel as the main carbon source. The purified enzyme was a glycoprotein and migrated as a single polypeptide band on polyacrylamide gel electrophoresis under native or denaturing conditions. The apparent molecular weight of the enzyme was estimated to be 55 kDa by gel filtration and SDS-PAGE. The enzyme was active against o-nitrophenyl beta-D-galactoside; p-nitrophenyl beta-D-glucoside, p-nitrophenyl beta-D-fucoside, lactose and cellobiose, PNP fucoside (synthetic substrate) and cellobiose (natural substrate) being the best utilized. A comparison of the properties of beta-D-galactosidase, beta-D-glucosidase and beta-D-fucosidase showed that three activities exhibited similar pH and temperature optima and the same thermostability. The hydrolysis rate of substrate mixtures suggests that the enzyme possesses a common catalytic site for all the substrates assayed.
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PMID:Beta-D-glycosidase activities of Humicola grisea: biochemical and kinetic characterization of a multifunctional enzyme. 210 72

A beta-glucosidase from the medium of an autolyzed culture of Penicillium oxalicum has been purified by tannic acid precipitation, sephacryl S-200, DEAE-Biogel, CM-Biogel and Mono Q successively. The purification process produced a homogeneous band in the SDS-PAGE that correspond to a Mr of 133,500. The enzyme had a pl of 4, and the active optima were found at pH 5.5 and 55 degrees C. The enzyme hydrolyzed different substrates showing maximum affinity against p-nitrophenyl-beta-D-glucoside with a Km value of 0.37 mM. The beta-glucosidase was inhibited by Glucono-D-lactone but not by glucose in the concentration range of 1 to 10 mM. The enzyme was adsorbed by Concanavalin-A-Sepharose.
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PMID:Purification and properties of a beta-glucosidase from Penicillium oxalicum autolysates. 210 21

A Clostridium cellulovorans lambda gt11 gene bank was screened for endo-1,4-beta-glucanase [EC 3.2.1.4, EGase, Carboxy Methyl Cellulase (CMCase)] genes using a chromogenic substrate. Three genes (engA, engB, and engC) were isolated. The engB expressed the most active CMCase. The engA encoded a bifunctional enzyme that displayed endo-1,4-beta-glucanase and beta-glucosidase activities. The three recombinant glucanases, when expressed in Escherichia coli, were partially degraded into multiform active enzymes as evidenced by their SDS-PAGE-CMC zymograms. None of the clones could degrade crystalline cellulose, thus supporting the hypothesis that the integrity of the C. cellulovorans cellulase complex was essential for its 'true cellulase' activity.
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PMID:Cloning of Clostridium cellulovorans endo-1,4-beta-glucanase genes. 211 83


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