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Publication Abstract from PubMed

beta-Glucosidase is the rate-limiting component of a cellulase-hydrolyzing reaction. Thermostability and glucose-tolerance are two critical criteria of the enzyme, which practically determine its performance in industrial applications. In this study, a thermostable and glucose-tolerant beta-glucosidase (named Bgl1317) belonging to the glycoside hydrolase family 1 was acquired from a metagenomic library of Turpan soil through functional screening. Bgl1317 showed excellent thermostability and glucose-tolerance and its crystal structure was subsequently determined at a high resolution. Rational design based on the structure was conducted, producing three beneficial mutations A397R, L188A and A262S. While A397R improved the cellobiose activity by 80%, L188A and A262S increased the IC50 value of glucose from 0.8 to 1.5M. The residues that may play a role in glucose-tolerance of GH1 beta-glucosidases were summarized and the performances of glucose-tolerant beta-glucosidases reported in recent years were discussed and compared. This study provides insights into enzymatic properties of Bgl1317 for engineering it into a powerful catalyst and beta-glucosidases in general.

Improving the cellobiose-hydrolysis activity and glucose-tolerance of a thermostable beta-glucosidase through rational design.,Liu X, Cao L, Zeng J, Liu Y, Xie W Int J Biol Macromol. 2019 Jun 12;136:1052-1059. doi:, 10.1016/j.ijbiomac.2019.06.029. PMID:31199970^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.