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

Lymphocytes, monocytes, neutrophilic granulocytes and platelets were each separated to greater than 95% purity from six normal subjects, three patients with Gaucher's disease, two heterozygotes for Gaucher's disease, and one patient with Fabry's disease. Activities of the following acid hydrolases were determined: "acid" (pH 4.0) beta-glucosidase, pH 5.0 beta-glucosidase, alpha-galactosidase, alpha-arabinosidase, alpha-mannosidase, alpha-glucosidase, beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, and acid phosphatase. Enzymatic activity varied greatly with cell type and the enzyme being measured; the importance of assaying pure preparations especially for heterozygote detection is emphasized. Gaucher's disease patients' cells were found to be deficient in the pH 4.0 acid beta-glucosidase, variable in the pH 5.0 beta-glucosidase, and normal in all other acid hydrolases tested, including acid phosphatase, the activity of which is known to be elevated in plasma. Blood cells of a patient with Fabry's disease were deficient in alpha-galactosidase and normal in all other acid hydrolases tested.
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PMID:Acid hydrolases in leukocytes and platelets of normal subjects and in patients with Gaucher's and Fabry's disease. 0 20

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

B and T lymphocytes were separated by means of the spontaneous sheep red blood cell rosette formation technique from 3 normal donors. The following acid hydrolases were biochemically determined on separated B and T lymphocytes: acid phosphatase, beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, alpha-arabinosidase, alpha-galactosidase, alpha-mannosidase, alpha-glucosidase, and pH 4.0 and pH 5.0 beta-glucosidase. The activities of most of the acid hydrolases including acid phosphatase and beta-glucuronidase were found to be slightly decreased in B lymphocytes when compared to T lymphocytes. However, alpha-mannosidase activity was found to be significantly higher in the B lymphocytes than in the T lymphocytes and offers the possibility of using this enzyme as a B lymphocyte marker.
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PMID:Acid hydrolases in normal B and T blood lymphocytes. 41 51

Beta-Glucosidase, beta-galactosidase, beta-xylosidase and alpha-L-arabinosidase activities of partially purified preparation of almond emulsin were investigated using chromatography, electrophoresis in polyacrylamide gel and isoelectric focusing. Beta-Glucosidase was found to exist as two components having equal molecular weight. Aggregation of the components with inactive proteins probably results in the appearance of multiple native forms which have similar specific activities. In no case separation of the beta-glucosidase activity from the accompanied activities was achieved. It is concluded therefore that these activities are exhibited by an enzyme which is not strictly specific to the C4, C6 stereochemistry for hexosides and to that of C4, C5 for pentozides.
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PMID:[Substrate specificity of sweet almond beta-glucosidase]. 85 2

An enzyme has been isolated from human liver by DEAE-cellulose chromatography and has been shown by competitive substrate inhibition to be capable of hydrolysing synthetic beta-D-galactosides, beta-D-glucosides, beta-D-fucosides, beta-D-xylosides, and alpha-L-arabinosides. Another form of alpha-L-arabinosidase activity elutes with the major beta-D-galactosidase component on DEAE-chromatography, but has a different identity on the basis of its stability at 4 degrees C. Liver samples from patients with Gaucher's disease are deficient in beta-D-fucosidase as well as beta-D-glucosidase activity.
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PMID:The common identity of five glycosidases in human liver. 126 36

Glycosidic activities have been examined in Candida albicans grown on medium culture containing latex sap (natural antifungal) or isoconazole (synthetic antifungal). The different types of utilized latex sap were those of Lactuca sativa (latex exuded from articulated laticifers) and Asclepias curassavica (latex flowing from non-articulated laticifers). The same enzyme assays were performed on C. albicans grown without antifungal compounds. Except for alpha-arabinosidase, all glycosidase activities were increased when C. albicans was grown in medium supplemented with L. sativa latex sap. The most stimulated activities were those of beta-fucosidase, alpha-galactosidase, alpha- and beta-glucosidase, alpha- and beta-mannosidase, acetyl-beta-glucosaminidase. The presence of A. curassavica latex sap in culture medium produced similar results: the most stimulated activities were those of alpha-mannosidase, alpha-galactosidase, acetyl-beta-glucosaminidase and beta-fucosidase. Electron microscope observations suggested a correlation between this stimulation of glycosidic activities and the fungal cell wall breakdown. For comparison the presence of isoconazole in culture medium yields no increase in glycosidic activities and no ultrastructural modification of fungal cell wall. The mode of action of latex saps in cell wall breakdown is discussed.
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PMID:Glycosidic activities of Candida albicans after action of vegetable latex saps (natural antifungals) and isoconazole (synthetic antifungal). 192 92

A circadian rhythm in acid phosphatase and hexosaminidase was found in adult male hamsters exposed to a long photoperiod (14:10 h light/dark [LD]; lights on 06.00 h) and killed at 08.00, 14.00, 20.00, 02.00, 04.00, 05.50 and 0.615 h. Hexosaminidase and beta-glucuronidase activity at 02.00, 04.00 and 05.50 h (values pooled for these times before lights on) were significantly elevated compared to enzyme activity at 06.15 and 08.00 h (pooled values after lights on), suggesting a fall in activity associated with lights on. Hypogonadism was induced in female Syrian hamsters by exposure to a short photoperiod (10:14 h LD) until a majority of them were vaginally acyclic. Pineal lysosomal enzyme activities (acid phosphatase, beta-glucuronidase, hexosaminidase, alpha-arabinosidase and beta-galactosidase) were significantly elevated in short photoperiod-exposed animals compared to animals in 14:10 LD, when measured near the middle of the light phase. In the third experiment, castrated animals were used to determine if lowered androgen levels might also affect pineal lysosomal enzyme activity. The results indicated that light phase beta-glucuronidase, hexosaminidase and beta-glucosidase activities were lower in castrated males compared to their intact controls. In summary, these results demonstrate that (1) lysosomal enzyme activity is present in the Syrian hamster pineal, (2) changes can be observed which suggest involvement of this activity in pineal function and, (3) a circadian rhythm in enzyme activity is present with peak activity occurring during the night. In the short photoperiod and castration experiments, the changes in lysosomal enzyme activity could reflect either a hormonal manipulation or a change in circadian regulation of enzyme activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pineal lysosomal enzymes in the Syrian hamster: circadian rhythm and effects of castration or short photoperiod treatment. 252 45

Glucosylsphingosine is a potent inhibitor of lysosomal glucocerebrosidase and the broad-specificity, cytosolic beta-glucosidase of human liver. In the present study, it was demonstrated that the broad-specificity beta-glucosidase was also inhibited by galactosylsphingosine. The inhibition was observed when the enzyme was assayed for beta-glucosidase, beta-galactosidase, beta-xylosidase, and alpha-arabinosidase activities. Inhibition was of the mixed-type and the degree of inhibition depended on the substrate. For example, galactosylsphingosine was a more potent inhibitor of beta-glucosidase activity (I0.5 = 0.3 mM) than beta-xylosidase activity (I0.5 = 1.2 mM). In addition, the observation that the broad-specificity, cytosolic beta-glucosidase was inhibited by hydrophobic glycosphingolipids prompted the definition of a revised purification procedure which took advantage of hydrophobic affinity chromatography. This revised purification scheme employed Octyl-Sepharose and yielded the largest (68,000 Da) and most active (470,000 nmol h-1 mg protein-1) beta-glucosidase preparation yet described. The beta-glucosidase preparation contained 19% serine and 17% glycine, while 24% of the total amino acids were hydrophobic. The results of this study document the presence of a sphingolipid binding site on the broad-specificity beta-glucosidase. The implications of galactosylsphingosine inhibition of cytosolic beta-glucosidase and the possible role of the enzyme in glycosphingolipid metabolism are discussed.
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PMID:Galactosylsphingosine inhibition of the broad-specificity cytosolic beta-glucosidase of human liver. 391

1. The previous study (Conchie, Gelman & Levvy, 1967b) of the specificity of beta-glucosidase, beta-galactosidase and beta-d-fucosidase in barley, limpet, almond emulsin and rat epididymis was extended to alpha-l-arabinosidase. 2. The inhibitory action of l-arabinono-(1-->5)-lactone was tested against all four types of enzyme, and alpha-l-arabinosidase was examined for inhibition by glucono-, galactono- and d-fucono-lactone. 3. In emulsin, the enzyme that hydrolyses beta-glucosides, beta-galactosides and beta-d-fucosides also hydrolyses alpha-l-arabinosides. Rat epididymis resembles emulsin except that, as already noted, it lacks beta-glucosidase activity. 4. In the limpet, alpha-l-arabinosidase activity is associated with the enzyme that hydrolyses beta-glucosides and beta-d-fucosides, and not with the separate beta-galactosidase. 5. The effects of the different lactones on the barley preparation suggest that alpha-l-arabinosidase activity is associated with the beta-galactosidase rather than with the enzyme that hydrolyses beta-glucosides and beta-d-fucosides. Fractionation and heat-inactivation experiments indicate that there is also a separate alpha-l-arabinosidase in the preparation.
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PMID:Inhibition of glycosidases by aldonolactones of corresponding configuration. The specificity of alpha-L-arabinosidase. 572 53


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