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)

1. The injection into mice of a single dose of conduritol B epoxide, a covalent inhibitor of glucosidases, quickly produced changes in tissue levels of beta-D-glucuronidase (EC 3.2.1.31). The specific activity of the enzyme decreased in liver, spleen and kidney while brain showed little change. The inhibitor did not act on glucuronidase in vitro, so the effect of the inhibitor is complex, possibly a result of the loss of glucosidase activity. Since glucuronidase contains glucose, we suggest that the transport of the enzyme between subcellular regions and tissues involves loss of part of the glucose moieties. 2. Levels of glucocerebrosidase (D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45) dropped very rapidly after epoxide injection, reaching a minimum at 1 h in liver. There was a noticeable restoration of activity within the next 1--2 h. Aryl beta-glucosidase (EC 3.2.1.21) decrease somewhat less than cerebrosidase, reaching a minimum within 2 h. It too showed some recovery of activity within 3 h. 3. Acid phosphatase rose slightly in liver but not in brain. alpha-L-Fucosidase and angiotensin-converting enzyme were not affected by the epoxide injection. The latter two enzymes are known to contain glucose. 4. Injection of a hemolyzing agent, phenylhydrazine, produced an increased level of glucuronidase in liver and spleen within 6 days, but not in kidney. This enhancement was a little less in mice previously injected with the glucosidase inhibitor. 5. Mice injected with the epoxide once a day eight times showed a distinct rise in brain glucuronidase level, as well as a rise in brain weight. However, the other organs showed only the same decrease in glucuronidase specific activity noted with the single injection protocol. It is suggested that the difference is due to the blood-brain barrier, which could slow the loss of brain glucuronidase from the extracellular fluid.
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PMID:Enzymic effects of beta-glucosidase destruction in mice. Changes in glucuronidase levels. 21 40

Eschscholtzia californica stigmas with germinating pollen at different stages of development were the subject of histochemical studies which aimed the localization of several enzymes like phosphorylase, leucine amino peptidase, nonspecific esterase, cytochrome oxidase, aldolase, alpha-glycerophosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, monoamine oxidase, alpha-galactosidase, beta-glucosidase and beta-galactosidase. Pollen and pollen tubes were shown to contain starch, lipid, proteins and soluble sugars as the storage products. These storage products were utilized during germination and tube growth. The role of different enzymes in the process of germination and tube growth is discussed. From the distribution of oxidoreductases it is inferred that respiration plays an essential role in the tube growth. During pollen germination probably the reserve proteins were transported to pollen tube tip. The increase of activity of alpha-and beta-galactosidase in pollen tubes indicates on their involvement in carbohydrate metabolism. The role of alpha-galactosidase in the metabolism of galactolipids is also inferred. Similarly, the reaction catalysed by beta-glucosidase resulted in the production of aglycon and glucose; of these the former possibly act as a substrate of peroxidase. Some of the glycosidases diffused out of pollen wall on the stigma and participated in the release of free sugars of the female tissue.
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PMID:Studies on the physiology of pollen and pollen tube growth. IV Eschscholtzia californica Cham. 22 Jan 58

The beta-glucosidase of Mucor racemosus was shown to be synthesized when the organism was grown in the presence of such diverse carbon sources as glycerol, lactate, xylose, ribose, alpha-methylglucoside, alpha-phenylglucoside, maltose, and cellobiose. Enzyme synthesis was strongly repressed in the presence of hexoses. In addition, exogenous cyclic adenosine 3',5'-monophosphate (cAMP) resulted in enzyme repression. When cAMP was added exogenously after enzyme activity had accumulated, a reversible enzyme inactivation occurred. Growth on disaccharides (maltose or cellobiose) was severely retarded in the presence of cAMP, whereas that on glucose remained unaffected. The results indicate a probable role for cAMP in control of glucosidase synthesis in Mucor.
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PMID:Control of beta-glucosidase synthesis in Mucor racemosus. 23 21

An intracellular beta-1,6-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) was produced semiconstitutively by Flavobacterium M64. This enzyme was purified 180-fold by fractionation with ammonium sulfate followed by chromatographies on carboxymethylcellulose, hydroxyapatite and Sephadex G-100. The final preparation appeared homogeneous on disc electrophoresis on polyacrylamide gel. The molecular weight of the enzyme was determined to be ca. 59 000 by Sephadex G-100 gel filtration and sodium dodecylsulfate-polyacrylamide gel electrophoresis. The optimum pH of the enzyme was 5.8 and the optimum temperature was 40 degrees C. The enzyme readily hydrolyzed oligomers with beta-a,6-glucosidic linkages, converting them to glucose. The Km values for gentio-biose, -triose, -tetraose and -pentaose were 2.8, 3.0, 4.2 and 4.6 times 10- minus 4 M, respectively. The rates of their hydrolyses decreased with increase in their chain lengths. The enzyme was concluded to be a beta-1,6-glucosidase from its substrate specificity, production of glucose, transferring ability and inhibition by glucono-delta-lactone. The enzyme activity was inhibited by Hg-2+, Cu-2+, Ag-+, Fe-3+, p-chloromercuribenzoate, N-ethylmaleimide, glucose and trishydroxyaminomethane (Tris) but not by ethylenediaminetetraacetic acid.
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PMID:Purification and properties of a beta-1,6-clucosidase from Flavobacterium. 23 5

beta-Glucosidases have been isolated from Alocasia macrorrhiza plants. The enzymes are highly specific for the hydrolysis of the cyanogenic glucoside triglochinin endogenous to this plant. Upon chromatography of protein extracts on cation exchange resins and Sephadex G-200, separation into various enzymatically active bands was observed. The main fractions possess molecular weights of approximately 310000 and 105 000, as shown by preparative ultracentrifugation in a linear saccharose gradient. The beta-glucosidases are composed of subunits (molecular weight 55 000 to 60 000), as revealed by sodium dodecylsulfate gel electrophoresis. The result of alkaline disc electrophoresis and isoelectric focusing in polyacrylamide gel suggest that the beta-glucosidase fraction with molecular weight 105 000 is a dissociation product of the 310 000 molecular-weight species. The isoelectric points of the various beta-glocusidase bands, obtained by isoelectric focusing, vary between pH 4.5 and 5.0. The beta-glucosidases show a pronounced specificity for triglochinin. The Km for this substrate (3 times 10(-5) M) is 50 to 100-fold lower than for all other substrates hydrolyzed. Of the other cyanogenic glycosides, only those with an aromatic aglycone, (S)-configuration at the asymmetric carbon atom of the aglycone and glucose as sugar moiety were hydrolyzed to a measurable extent. The pH optimum of the enzyme reaction is 5.5, the temperature optimum around 50 degrees C. Cu2 ions and glucono-1,5-lactone inhibit beta-glucosidase activity approximately 50% at a concentration of 5 times 10(-4) M, while Hg2,Ag and p-chloromercuribenzoate show the same percent inhibition at 5 times 10(-7) M. Lipophilic solvents (ethanol, ethylene glycol monomethylether) activate the beta-glucosidase activity, preferentially by influencing the V values of the enzymes.
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PMID:[Glucosidases specific for the cyanogenic glucoside triglochinin. Purification and characterization of beta-glucosidases from Alocasia macrorrhiza Schott]. 24 Jul 69

We have previously described the structure of phellamurin, a plant flavonoid, as 3,4',5,7-tetrahydroxy-8-isoprenylflavanone-7-O-glucoside (17). Degradation of phellamurin by Aspergillus niger using modified Czapek-Dox medium as well as phellamurin or one of its degradation products as a sole carbon source, is reported here. Eleven compounds are identified from phellamurin degradation products. A. niger apparently decomposes phellamurin by first removing glucose with beta-glucosidase; neophellamuretin is the first degradation product. Fission of the heterocyclic ring of (5''-hydroxyisopropyl-4'',5''-dihydrofurano)[2'',3''-h]3,4',5-trihydroxyflavanone, which is obtained from neophellamuretin through a few alterations of the side chain, is followed by cleavage of a C--C bond between C=O and carbon at alpha-position and conversion of (5''-hydroxyisopropyl-4'',5''-dihydrofurano)[2'',3''-d]-2',4,6',alpha-tetrahydroxychalcone to rho-hydroxymandelic acid (B-ring) and 2,4,6-trihydroxy-5-carboxyphenylacetic acid (A-ring). It is suggested that rho-hydroxymandelic acid is oxidized to rho-hydroxybenzoic acid. 2,4,6-Trihydroxy-5-carboxyphenylacetic acid is metabolized to phloroglucinol carboxylic acid, which subsequently is decarboxylated to phloroglucinol. These results provided new information on the isoprene unit metabolism of the side chain of phellamurin and firmly established the degradation pathway of phellamurin by A. niger.
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PMID:Degradation of the plant flavonoid phellamurin by Aspergillus niger. 41 68

Three distinct cellobiase components were isolated from a commercial Trichoderma viride cellulase preparation by repeated chromatography on DEAE cellulose eluting by a salt gradient. The purified cellobiase preparations were evaluated for physical properties, kinetics, and mechanism. Results from this work include: 1) development of one step enzyme purification procedure using DEAE-cellulose; 2) isolation of three chromatographically distinct, yet kinetically similar, cellobiase fractions of molecular weight of approximately 76,000; 3) determination of kinetics which shows that cellobiase hydrolyzes cellobiose by a noncompetitive mechanism and that the product, glucose, inhibits the enzyme, and 4) development of an equation, based on the mechanism of cellobiase action, which accurately predicts the time course of cellobiose hydrolysis over an eightfold range of substrate concentration and conversions of up to 90%. Based on the data presented in the paper, it is shown that product inhibition of cellobiase significantly retards the rate of cellobiose hydrolysis.
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PMID:Cellobiase from Trichoderma viride: purification, properties, kinetics, and mechanism. 56 Feb 23

A procedure for the estimation of D- and D,L-amygdalin in urine is described. Amygdalin is hydrolyzed by beta-glucosidase and base to benzaldehyde, glucose and cyanide. Benzaldehyde is extracted with methylene chloride and the ultraviolet (UV) absorbence determined at 243 nm. The response of human urine "spiked" with amygdalin was linear between 10 and 75 microgram/ml. Mice administered 100 mg/kg of amygdalin intravenously or orally excreted about 70 and 20% of the administered dose, respectively, over 96 hours. In each instance more than 96% of excreted drug equivalents were obtained within the first 24 hours.
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PMID:A simple method for the estimation of amygdalin in the urine. 56 46

Serum enzymes have not proved useful in evaluation of patients with early colon cancer, but certain enzymes such as transpeptidase, phosphohexone isosomerase, or 5'-nucleotidase have been of assistance in following the course of the disease, particularly in patients with metastatic spread to the liver. Attempts have been made to improve the utility of enzyme analysis in colon cancer by examination of enzyme patterns in colon biopsy specimens, feces, and colon washings. These studies, which will be summarized, are of importance in the possible development of diagnostic tools and as probes in the understanding of the etiology of colon cancer. The technical problems in carrying out these assays in humans, as well as the significance of the activity of aryl sulfatase, beta-glucuronidase, beta-glucosidase, lactic dehydrogenase, glucose-6-p-osphate dehydrogenase, and other enzymes will be considered.
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PMID:Enzymes in colon cancer. General information. 76 57

The enzymatic conversion of cellulose is catalyzed by a multiple enzyme system. The Trichoderma enzyme system has been studied extensively and has insufficient beta-glucosidase (EC 3.2.1.21) activity for the practical saccharification of celluose. The black aspergilli (A. niger and A. phoenicis) were superior producers of beta-glucosidase and a method for production of this enzyme in liquid culture is presented. When Trichoderma cellulase preparations are supplemented with beta-glucosidase from Aspergillus during practical saccharifications, glucose is the predominant product and the rate of saccharification is significantly increased. The stimulatory effect of beta-glucosidase appears to be due to the removal of inhibitory levels of cellobiose.
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PMID:beta-Glucosidase: microbial production and effect on enzymatic hydrolysis of cellulose. 83 51


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