Download MendeleyImproving 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.(2019) Int J Biol Macromol 136: 1052-1059
- PubMed: 31199970
- DOI: https://doi.org/10.1016/j.ijbiomac.2019.06.029
- Primary Citation of Related Structures:
6IER - PubMed Abstract:
β-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 β-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 IC 50 value of glucose from 0.8 to 1.5 M. The residues that may play a role in glucose-tolerance of GH1 β-glucosidases were summarized and the performances of glucose-tolerant β-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 β-glucosidases in general.
Organizational Affiliation:
MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China.
