Enhancing the thermal stability of Xylanase HWxyn11 through N-terminal substitution and C-terminal carbohydrate
Huifang Zhang1, Qinzhou Cai1, Yating Long1
1School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Abstract:
Xylanases from glycoside hydrolases family 11 (GH11) are widely used due to their substrate selectivity and broad optimal pH range. With the increasing demands in industrial production, the development of xylanases with multiple stress resistances and high thermostability has become a research focus. We heterologously expressed and characterized a novel GH11 xylanase (HWxyn11) from Hortaea werneckii. The optimal catalytic temperature and pH of HWxyn11 are 45 °C and 5, respectively. Through N-terminal replacement and C-terminal fusion with a carbohydrate binding module (CBM), the thermostability of HWxyn11 was significantly enhanced. Among them, variant HWxA31-CBM6 retained 65 % of its activity after incubation at 55 °C for 60 min, which was 3.4-fold higher than that of wild-type HWxyn11. Molecular simulations indicate that the modifications decreased the flexibility of the N- and C-terminal regions and enhanced overall structural stability. This study improved the industrial potential of HWxyn11 and provided an effective strategy for enhancing the thermostability of GH11 xylanases.
