A mechanism of glucose tolerance and stimulation of GH1 β-glucosidases

Authors

Yang Yang, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and Biocatalysis
Xinxin Zhang, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and Biocatalysis
Qiang Yin, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and Biocatalysis
Wei Fang, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and BiocatalysisFollow
Zemin Fang, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and BiocatalysisFollow
Xiaotang Wang, Department of Chemistry and Biochemistry, Florida International UniversityFollow
Xuecheng Zhang, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and BiocatalysisFollow
Yazhong Xiao, Anhui University; Anhui Provincial Engineering Technology Research Center for Microorganisms and BiocatalysisFollow

Date of this Version

11-25-2015

Document Type

Article

Abstract

β-Glucosidases are enzymes that hydrolyze β-glycosidic bonds to release non-reducing terminal glucosyl residues from glycosides and oligosaccharides, and thus have significant application potential in industries. However, most β-glucosidases are feedback inhibited by the glucose product, which restricts their application. Remarkably, some β-glucosidases of the glycoside hydrolase (GH) 1 family are tolerant to or even stimulated by glucose. Elucidation of the mechanisms of glucose tolerance and stimulation of the GH1 β-glucosidases will be crucial to improve their application through enzyme engineering. In this study, by comparing the primary and tertiary structures of two GH1 β-glucosidases with distinct glucose dependence, some putative glucose-dependence relevant sites were mutated to investigate their exact roles. Both biochemical and structural characterization of the mutants suggested that some sites at the entrance and middle of the substrate channel regulate the effects of glucose, and the relative binding affinity/preference of these sites to glucose modulates the glucose dependence. A mechanism was therefore proposed to interpret the glucose dependence of GH1 β-glucosidases. This research provides fresh insight into our current understanding of the properties and mechanisms of GH1 β-glycosidases and related enzymes that modulate their activity via feedback control mechanism.

Comments

This article was originally published in Scientific Reports.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Yang, Y. et al. A mechanism of glucose tolerance and stimulation of GH1 β-glucosidases. Sci. Rep. 5, 17296; doi: 10.1038/srep17296 (2015).