The β-glucosidase encoded by the td2f2 gene was isolated from a compost microbial metagenomic library by functional screening. The protein was identified to be a member of the glycoside hydrolase family 1 and was overexpressed in Escherichia coli, purified, and biochemically characterized. The recombinant β-glucosidase, Td2F2, exhibited enzymatic activity with β-glycosidic substrates, with preferences for glucose, fucose, and galactose. Hydrolysis occurred at the nonreducing end and in an exo manner. The order of catalytic efficiency for glucodisaccharides and cellooligosaccharides was sophorose > cellotetraose > cellotriose > laminaribiose > cellobiose > cellopentaose > gentiobiose, respectively. Intriguingly, the p-nitrophenyl-β-d-glucopyranoside hydrolysis activity of Td2F2 was activated by various monosaccharides and sugar alcohols. At a d-glucose concentration of 1000 mm, enzyme activity was 6.7-fold higher than that observed in the absence of d-glucose. With 31.3 mm d-glucose, Td2F2 catalyzed transglycosylation to generate sophorose, laminaribiose, cellobiose, and gentiobiose. Transglycosylation products were detected under all activated conditions, suggesting that the activity enhancement induced by monosaccharides and sugar alcohols may be due to the transglycosylation activity of the enzyme. These results show that Td2F2 obtained from a compost microbial metagenome may be a potent candidate for industrial applications.
There is an ongoing search for a β-glucosidase that has insensitivity to product inhibition.
A β-glucosidase, Td2F2, was isolated from a metagenomic library and has high glucose tolerance, and its activity is enhanced by various monosaccharides.
The high glucose tolerance of Td2F2 is related to high transglycosylation activity.
This is the first report of a β-glucosidase having high glucose tolerance and high transglycosylation activity.
TI - Characterization of a Novel β-Glucosidase from a Compost Microbial Metagenome with Strong Transglycosylation Activity * JO - Journal of Biological Chemistry DO - 10.1074/jbc.m113.471342 DA - 2013-06-21 UR - https://www.deepdyve.com/lp/american-society-for-biochemistry-and-molecular-biology/characterization-of-a-novel-glucosidase-from-a-compost-microbial-ACD7nC0V2O SP - 18325 EP - 18334 VL - 288 IS - 25 DP - DeepDyve ER -