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)

From the fruiting bodies of the edible mushroom Flammulina velutipes a single-chained ribosome inactivating protein with a molecular weight of 13.8 kDa was isolated with a procedure involving ion exchange chromatography on DEAE-cellulose and SP-Sepharose and affinity chromatography on Affi-gel blue gel. The protein was novel in that it possessed a molecular weight lower than those of previously reported RIPs and that it was capable of inhibiting human immunodeficiency virus (HIV-1) reverse transcriptase, beta-glucosidase and beta-glucuronidase. Its N-terminal sequence exhibited a certain degree of similarity to those of plant ribosome inactivating proteins.
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PMID:Isolation and characterization of velutin, a novel low-molecular-weight ribosome-inactivating protein from winter mushroom (Flammulina velutipes) fruiting bodies. 1132 20

From the roots of the Chinese medicinal herb Pseudostellaria heterophylla a single-chained lectin with a molecular weight of 36 kDa and high hemagglutinating activity was isolated. The lectin was adsorbed on DEAE-cellulose in 10 mM Tris-HCI buffer (pH 7.4) and was eluted by the same buffer containing 50 mM NaCl. It was adsorbed on SP-Sepharose in 10mM NH4OAc (pH 4.5) and eluted by approximately 0.5 M NaCl in the same buffer. The hemagglutinating activity of the lectin could not be inhibited by a large variety of monosaccharides, but was largely abrogated by exposure to 0.05 M HCl, 0.05M NaOH or 80 degrees C. However, about 50% of the activity remained after exposure to 0.025M NaOH or 40 degrees C. Despite possession of an N-terminal sequence exhibiting some similarity to thaumatin-like proteins with antifungal activity, the lectin was devoid of antifungal activity. The lectin exerted some inhibitory effect on the glycohydrolases alpha-glucosidase, beta-glucosidase and beta-glucuronidase which are involved in HIV infection but had no suppressive action on human immunodeficiency virus-type 1 reverse transcriptase.
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PMID:A novel lectin from Pseudostellaria heterophylla roots with sequence simularity to Kunitz-type soybean trypsin inhibitor. 1144 23

The gene coding for beta-glycosidase (EC 3.2.1.21) from Thermus nonproteolyticus HG102 was cloned and expressed in Escherichia coli. The gene open reading frame was 1311 bp, and it codes for 437 amino acids. The deduced amino acid sequence of the enzyme showed identity with members of the glycosyl hydrolase family I. The enzyme had high content of Arg and Pro. The recombinant enzyme was purified to homogeneity with heat precipitation, ammonium sulfate precipitation, DEAE-cellulose (DE52) chromatography, and prepared slab polyacrylamide gel electrophoresis. The enzyme was monomeric and had a molecular mass of 48,900 Daltons and a pI of 5.2. The enzyme showed optimum activity at pH 5.6 and 90 degrees C. It catalyzed the hydrolysis of beta-D-glucoside, beta-D-galactoside, beta-D-fucoside, and beta-D-mannoside. Lineweaver-Burk plots showed that the kcat/Km ratio for beta-D-glucoside and beta-D-fucoside was higher than for beta-D-mannoside and beta-D-galactoside. The enzyme was extremely thermostable, with a half-life of 2.5 h at 90 degrees C, and was stable over a wide range of pH. It also had transglycosidic activity at high temperature.
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PMID:Cloning and expression of thermostable beta-glycosidase gene from Thermus nonproteolyticus HG102 and characterization of recombinant enzyme. 1156 26

The thermophilic fungus Chaetomium thermophilum var. coprophilum produced large amounts of extracellular and intracellular beta-glucosidase activity when grown on cellulose or cellobiose as carbon sources. The presence of glucose in the culture medium drastically decreased the level of beta-glucosidase activity, while cycloheximide prevented the induction of the extracellular enzyme activity by cellobiose. An extracellular beta-glucosidase induced by avicel was purified by a procedure involving acetone precipitation and chromatography on two DEAE-cellulose columns. The purified enzyme was a basic protein, with a carbohydrate content of 73%. The deglycosylated enzyme exhibited a molecular mass of 43 kDa, with pH and temperature optima of 5.5 and 65 degrees C respectively. The beta-glucosidase hydrolysed only cellobiose and p-nitrophenyl-beta-D-glucopyranoside, exhibiting apparent Km values of 3.13 mM and 0.76 mM, respectively. The native purified enzyme was stable up to 2 hours at 60 degrees C, and its thermal stability was directly dependent on glycosylation.
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PMID:Extracellular beta-D-glucosidase from Chaetomium thermophilum var. coprophilum: production, purification and some biochemical properties. 1193 Sep 43

Acetyl esterase (AE) activity present in the culture filtrate of Termitomyces clypeatus was separated into lower molar mass (LMM) and higher molar mass (HMM) protein fractions during BioGel P-200 gel chromatography. AE was purified as a 30 kDa nonglycosylated protein from LMM fractions by CM-Sepharose ion exchange chromatography and HPGPLC. Although the HMM fraction had a number of enzyme activities (sucrase, beta-xylosidase, beta-glucosidase, and alpha-L-arabinofuranosidase) other than AE, protein present in the fraction was eluted as a single protein peak in HPGPLC and gave a single band in native PAGE. The fraction, subsequently purified by DEAE-Sephadex chromatography, was a SDS-PAGE homogeneous 80 kDa glycoprotein, but with both AE and cellobiase activities. The aggregate dissociated during ConA-Sepharose chromatography and 30 kDa AE and 56 kDa glycosylated cellobiase were purified separately. The dissociation caused significant loss of cellobiase activity but not that of AE. AE purified from both HMM and LMM fractions was characterized to be the same enzyme in terms of molar masses, pI (7.3), and other physicochemical properties. AE as an aggregate with cellobiase showed higher thermostability, temperature optimum, and resistance toward chemical denaturants than those of purified AE. Compared to cellobiase purified earlier from the same fungus, the enzyme present with AE in the aggregate also showed higher catalytic activity, thermostability, and temperature optimum. The study indicated that the formation of such SDS-resistant enzyme aggregate was associated with significant changes in the physicochemical properties of the enzymes, mainly toward improvement of rigidity of enzymes, and sometimes with the improvement of catalytic activity.
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PMID:Protein-protein interaction conferring stability to an extracellular acetyl (xylan) esterase produced by Termitomyces clypeatus. 1279 Jun 30

An isoflavone conjugates hydrolyzing beta-glucosidase (ICHG) from endophytic bacterium, Pseudomonas ZD-8 was purified to homogeneity by successive ammonium sulfate precipitation, gel filtration on SephadexG-100, DEAE-sephrose CL-6B and DEAE-Sephacel chromatography. The enzyme was a monomeric protein with an apparent molecular mass of 33 kDa as determined by SDS-PAGE and gel filtration. It was optimally active at pH 6.0 and 40 degrees C and had a specific activity of 1485 U mg of protein(-1) against genistin. The ICHG readily hydrolyzed rho-nitrophenyl-beta-glucoside, rho-nitrophenyl-beta-galactoside, genistin, daidzin, with Km values of 1.64, 1.87, 0.012, 0.014 mM, respectively. The ICHG showed a pronounced specificity for glucose in the 7-position of isoflavone and flavone conjugates and hydrolyzed effectively malonyl isoflavone glucosides as well as isoflavone glucosides with similar kinetics. Glucose and glucono-delta-lactone inhibited the enzyme competitively with Ki values of 84 mM and 23 mM, respectively. The enzyme did not require divalent cations for activity, and its activity was strongly inhibited by Hg2+, Ag+, rho-chloromercuribenzoate, iodoacetic acid, and N-ethylmaleimide while reducing agents such as beta-mercaptoethanol, dithiothreitol, dithioerythritol, glutathione slightly activated the enzyme.
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PMID:Purification and characterization of an isoflavone-conjugates-hydrolyzing beta-glucosidase from endophytic bacterium. 1505 33

An extracellular beta-glucosidase was extracted from the culture filtrate of Aspergillus niger No. 5.1 and purified to homogeneity by using ammonium sulfate precipitation, Chitopearl-DEAE chromatography, and Sephadex G-100 chromatography. The specific activity of the enzyme was enriched 6.33-fold, with a recovery of 11.67%. The enzyme was a monomer and the molecular mass was 67.5 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 66.5 kDa by gel-filtration chromatography. The enzyme had optimum activity at pH 6.0 and 60 degrees C and was stable over the pH range of 3.0-9.0. It showed specificity of hydrolysis for p-nitrophenyl-beta-D-glucoside and cellobiose. The Km and Vmax values of the enzyme for cellobiose and salicin were 5.34 mM, 2.57 micromol/(mL.s), and 3.09 mM, 1.34 micromol/(mL.s), respectively. Both amino acid composition and N-terminal amino acid sequence of the enzyme were determined, which provides useful information for cloning of this enzyme.
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PMID:Purification and characterization of an extracellular b-glucosidase with high transglucosylation activity and stability from Aspergillus niger No. 5.1. 1559 16

The present study analyzed the existence of carbohydrases in camel pancreas compared to some other ruminants. Disaccharidases (maltase, cellobiase, lactase, trehalase and sucrase), glucoamylase and alpha-amylase were detected in pancreas of camel, sheep, cow and buffalo. Enzyme levels in sheep were lower than in the other ruminants. The highest level was detected for alpha-amylase (EC 3.2.1.2). Moderate activity levels were detected for glucoamylase (EC 3.2.1.3) and maltase (EC 3.2.1.20), while other disaccharidases showed very low activity. The results suggested that, in addition to alpha-amylase, glucoamylase and maltase may be synthesized and secreted from pancreas to the small intestine in ruminants. Camel pancreatic glucoamylase was purified and characterized. The purification procedure included glycogen precipitation and chromatography on DEAE-Sepharose and Sepharose 6B. The molecular mass was 58 kDa for native and denatured enzyme using gel filtration and SDS-PAGE, respectively. The enzyme had a pH optimum at 5.5 and a Km of 10 mg starch/mL with more affinity toward potato soluble starch than the other carbohydrates. Glucoamylase had a temperature optimum at 50 degrees C with heat stability up to 30 degrees C. The effect of different cations and inhibitors was examined. The camel pancreatic glucoamylase may possess an essential thiol.
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PMID:Carbohydrases in camel (Camelus dromedarius) pancreas. Purification and characterization of glucoamylase. 1562 12

Chaetomium thermophilus CT2 was a cellulolytic fungus. It was a widely-existing saprophyte, which grower rapidly in soil. The cellulases synthesized by C. thermophilus CT2 was overall, consisting of three principal types of enzymes. The cellobiohydrolase was one of these three cellulases, which was associated with the endo-beta-1,4-glucanase and beta-glucosidase activities. C. thermophilus CT2 produced cellobiohydrolase available at 50 degrees C, when grown on ferment liquid substrate, containing 1% Avicel, 0.14% (NH4 )2SO4, 0.2% KH2PO4, 0.03% CaC2 x 2H2O, 0.03% MnSO4 x 7H2O, 0.1% peptone, 0.05% yeast extract, 0.1% Tween 80 and trace element solution at 1mL/L, containing 18mmol/L FeSO4 x 7H2O, 6.6mmol/L MnSO4, 4.8mmol/L ZnSO4 x 7H2O and 15mmol/L COCl2. A cellobiohydrolase was purified to homogeneity by an inexpensive and straightforward method for extraction of the enzyme involving fractional ammonium sulphate precipitation, ion-exchange chromatography on DEAE-Sepharose Fast Flow, gel filtration on Sephacryl S-100 and ion-exchange chromatography on Q Sepharose Fast Flow. The molecular weight of the enzyme was estimated to be 66.3kDa by 12.5% SDS-PAGE and was to be 67.1kDa by gel filtration on Sephacryl S-100 respectively. Kinetic studies of the purified cellobiohydrolase of C. thermophilus CT2 showed that the Km for p-NPC (p-trophenylbeta-d-cellobioside) was 0.956mmol/L as determined from a Lineweaver-Bark plot. Optimum enzyme activity was at 65 degrees C and pH5.0. It was thermostable at 60 degrees C and remained 20% activity after 20min at 80 degrees C. The half life time of the enzyme at 70 degrees C was 1h. It indicated that the cellobiohydrolase possessed of excellent acid stability and thermostable property. The properties of the cellobiohydrolase make it possible to be good material in scientific researches of protein thermostable mechanism and good model for designing and constructing a new type protein in industry. The enzyme may also provide instructive insight on the diversity and mechanism of cellulose degradation by C. thermophilus CT2. As a thermophilic fungus C. thermophilus CT2 is an attractive potential source of cellulases. It indicates that C. thermophilus CT2 may be a new excellent industrialized fungus for producing cellulases through molecule biology means.
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PMID:[Purification and characterization of a cellobiohydrolase from the thermophilic fungus Chaetomium thermophilus CT2]. 1657 83

Heat-stable activators of membranous beta-glucan synthase have been isolated from the supernatant fraction of crude mung bean (Vigna radiata) extracts by DEAE-cellulose and silica-gel chromatography. One of the activators has been partially purified and characterized on the basis of susceptibility to various enzymes and by analysis of the products formed upon total acid hydrolysis, alkaline-methanolysis, and beta-glucosidase digestion. This activator has the characteristics of a 1,2-dioleoyl diglyceride containing beta-linked glucose residue(s) at the C-3 position. When expressed per mole of glucosyl residues, the maximal K(a) value of the activator is estimated to be 25 micromolar. Both the intact glucosyl and fatty acid moiety are essential to the stimulatory effect of the activator.
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PMID:beta-Glucoside Activators of Mung Bean UDP-Glucose: beta-Glucan Synthase : I. Identification of an Endogenous beta-Linked Glucolipid Activator. 1666 38


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