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)

Agrobacterium tumefaciens beta-glucosidase, Cbg1 was extensively characterised and found to be a retaining aryl-glucosidase and an aryl-xylosidase. Cbg1s specificity for p-nitrophenyl beta-d-xylopyranoside was 73% that for p-nitrophenyl beta-d-glucopyranoside when measured by the ratio kcat/Km. The enzyme also hydrolysed p-nitrophenyl beta-d-fucopyranoside, and p-nitrophenyl beta-d-galactopyranoside with moderate efficiency. The enzyme released only terminal glucose from p-nitrophenyl beta-cellobioside and had a 20 000-fold preference for its natural substrate coniferin over cellobiose as indicated by the ratio kcat/Km. The enzyme was activated in the presence of 20 mM 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol. In the case of butanol this activation was investigated and shown to be due to transglycosylation activity with over 80% of p-nitrophenyl beta-d-glucopyranoside being converted to 1-butyl beta-d-glucopyranoside in the presence of Cbg1 and 100 mM 1-butanol.
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PMID:Agrobacterium tumefaciens beta-glucosidase is also an effective beta-xylosidase, and has a high transglycosylation activity in the presence of alcohols. 963 May 31

A gene encoding a putative beta-glucosidase was isolated from Thermoascus aurantiacus IFO9748 and designated as bgl2. The recombinant enzyme showed beta-glucosidase activity when p-nitrophenyl-beta-glucose (pNP-Glc) was used as substrate. We also found that the enzyme activity was increased in the presence of organic solvents. An addition of 20 % (v/v) 1-octanol resulted in 54-fold higher activity of pNP-Glc hydrolysis, and transglycosylation activity was also found to be activated. The results of tryptophan fluorescence spectral analysis revealed the changes in the tertiary structure of the enzyme in the presence of 1-hexanol that may cause increased enzyme activity. BGLII has a distinctive hydrophobic linker region between N- and C-terminal domains. A chimeric enzyme in which the linker region was substituted by the corresponding region of another beta-glucosidase failed to be activated by organic solvents, suggesting that the hydrophobic linker region may act as a molecular switch in BGLII.
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PMID:Unusual hydrophobic linker region of beta-glucosidase (BGLII) from Thermoascus aurantiacus is required for hyper-activation by organic solvents. 1661 58

Gold-cellobiose nanocomposites (GCNCs) were synthesized by reducing gold salt with a polysaccharide, cellobiose. Here, cellobiose acted as a controller of nucleation or stabilizer in the formation of gold nanoparticles. The obtained GCNCs were characterized with UV-visible spectroscopy; Zetasizer and Fourier transform infrared (FT-IR) spectrophotometer. Moreover, 6-Mercapto-1-hexanol (MCH) was modified on GCNCs, and the MCH-GCNCs were used to determine the cellobiase activity in compost extracts based on the surface plasmon resonance (SPR) property of MCH-GCNCs. The degradation of cellobiose on MCH-GCNCs by cellobiase could induce the aggregation, and the SPR absorption wavelength of MCH-GCNCs correspondingly red shifted. Thus, the absorbance ratio of treated MCH-GCNCs (A650/A520) could be used to estimate the cellobiase activity, and the probe exhibited highly sensitive and selective detection of the cellobiase activity with a wide linear from 3.0 to 100.0U L(-1) within 20 min. Meanwhile, a good linear relationship with correlation coefficient of R2=0.9976 was obtained. This approach successfully showed the suitability of gold nanocomposites as a colorimetric sensor for the sensitive and specific enzyme activity detection.
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PMID:Synthesis of gold-cellobiose nanocomposites for colorimetric measurement of cellobiase activity. 2488 98