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)

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

Lysosomal membrane fractions were prepared from lysosomes of mouse liver by freeze-thawing in a hypotonic buffer: 54% of beta-glucosidase [EC 3.2.1.45] in lysosomes was associated with the membrane fractions, whereas 96% of beta-glucuronidase [EC 3.2.1.31] was recovered in the soluble fractions of lysosomes. beta-glucosidase was solubilized by pH 9.5 treatment or by Triton treatment of membranes. The enzyme solubilized with alkali and concentrated with (NH4)2SO4 was rapidly inactivated in a solution of pH 9.5, but could be protected against inactivation by acidic detergent. Gel filtration analysis indicated that beta-glucosidase was in an aggregated form at neutral pH and could be disaggregated by alkali and detergents. The enzyme dissociated with detergents also showed a higher activity than the alkali-treated enzyme. These results suggested that beta-glucosidase is a peripheral enzyme bound to acidic lipids in membranes. beta-Glucosidase was purified to apparent homogeneity by (NH4)2SO4 fractionation and chromatographies with Sephacryl S-300, hydroxylapatite and cation exchangers in the presence of detergents. The catalytic activity of the purified enzyme was maximally stimulated by phosphatidylserine and heat-stable protein in the presence of a low concentration of Triton X-100. The stimulation was mainly due to an increase in Vmax.
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PMID:Characterization of beta-glucosidase as a peripheral enzyme of lysosomal membranes from mouse liver and purification. 393 51

Leukocytes were isolated from 14 patients (7 males and 7 females ) with Gaucher disease of the Norrbottnian type (Type 3), 32 obligate heterozygotes (16 males and 16 females) for this disease and 20 controls (10 males and 10 females). After collection, the cells were transported in dry ice to the laboratory, where they were assayed. The assays were repeated after the cells had been stored for 12 months. beta-Glucosidase activity was assayed with D-[glucose-U-14C]glucosylceramide at pH 5.8 with Cutscum-Na-cholate as a detergent and 4-methylumbelliferyl-beta-glucoside at pH 4.1 with Triton-Na-taurocholate as a detergent. The activities of two marker enzymes, 4-methylumbelliferyl-beta-galactosidase and N-acetyl-beta-glucosaminidase, were assayed in aliquots of the same leukocyte samples. The activity of beta-galactosidase remained constant during storage, N-acetyl-beta-glucosaminidase increased, while beta-glucosidase decreased as assayed with the natural as well as with the artificial substrate. beta-Glucosidase activity was significantly lower in the female than in male controls and heterozygotes. When assayed with natural substrate beta-glucosidase activity in leukocytes from the male patients was 6--12% of the control mean value and 10--15% in those from the female patients. The corresponding figures found when the artificial substrate was used were 15--30% and 22--45%. The values for the heterozygotes were respectively 42--68% and 34--79% with the natural substrate, and 33--82% and 51--109% with the artificial substrate. No correlation was found between the age of the patient and the beta-glucosidase activity.
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PMID:Assay of the beta-glucosidase activity with natural labelled and artificial substrates in leukocytes from homozygotes and heterozygotes with the Norrbottnian type (Type 3) of Gaucher disease. 677 5

An alpha-L-rhamnosidase clone was isolated from a genomic library of the thermophilic anaerobic bacterium Clostridium stercorarium and its primary structure was determined. The recombinant gene product, RamA, was expressed in Escherichia coli, purified to homogeneity and characterized. It is a dimer of two identical subunits with a monomeric molecular mass of 95 kDa in SDS polyacrylamide gel electrophoresis. At pH 7.5 it is optimally active at 60 degrees C and insensitive to moderate concentrations of Triton X100, ethanol and EDTA. It hydrolysed p-nitrophenyl-alpha-L-rhamnopyranoside, naringin and hesperidin with a specific activity of 82, 1.5 and 0.46 U mg-1 respectively. Hydrolysis occurs by inversion of the anomeric configuration as detected using 1H-NMR, indicating a single displacement mechanism. Naringin was hydrolysed to rhamnose and prunin, which could further be degraded by incubation with a thermostable beta-glucosidase. The secondary structure of RamA consists of 27% alpha-helices and 50% beta-sheets, as detected by circular dichroism. The primary structure of the ramA gene has no similarity to other glycoside hydrolase sequences and possibly is the first member of a new enzyme family.
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PMID:The thermostable alpha-L-rhamnosidase RamA of Clostridium stercorarium: biochemical characterization and primary structure of a bacterial alpha-L-rhamnoside hydrolase, a new type of inverting glycoside hydrolase. 1063 87

Soil enzyme activities and heavy metal concentrations (Cd, Zn, Cu and Pb) were measured at a general shooting range in South Korea. Total heavy metal concentrations varied with pH, and were negatively correlated with moisture content and organic matter. Most enzyme activities (dehydrogenase, acid phosphatase and beta-glucosidase) and ATP values (measure of biomass) were lower in polluted soils, especially in bald spots contaminated by heavy metals and TNT (2,4,6-trinitrotoluene). These data indicate that concentrated shooting activity inhibits enzyme activity and microbial growth. Soil enzyme activities in richly vegetated spots around the general shooting range were higher (2- to 3-fold) than in bald spots, but lower in areas of heavy metal contamination. Our results demonstrate that the dominant plant species in richly vegetated spots accumulated heavy metals from soils, and suggest certain plants may be useful for decontaminating polluted soil.
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PMID:Heavy metal concentrations and enzyme activities in soil from a contaminated Korean shooting range. 1623 26