Engineering the thermostability of D-lyxose isomerase from Caldanaerobius polysaccharolyticus via multiple computer-aided rational design for efficient synthesis of D-mannose  

作　　者：Hao Wu Ming Yi Xiaoyi Wu Yating Ding Minghui Pu Li Wen Yunhui Cheng Wenli Zhang Wanmeng Mu 

机构地区：[1]School of Food Science and Bioengineering,Changsha University of Science&Technology,Changsha,410114,China [2]State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi,214122,China

出　　处：《Synthetic and Systems Biotechnology》2023年第2期323-330,共8页合成和系统生物技术（英文）

基　　金：supported by the National Natural Science Foundation of China(32201963);Scientific Research Foundation of Hunan Provincial Education Department(22C0137).

摘　　要：D-Mannose is an attractive functional sugar that exhibits many physiological benefits on human health.The demand for low-calorie sugars and sweeteners in foods are increasingly available on the market.Some sugar isomerases,such as D-lyxose isomerase(D-LIase),can achieve an isomerization reaction between D-mannose and D-fructose.However,the weak thermostability of D-LIase limits its efficient conversion from D-fructose to D-mannose.Nonetheless,few studies are available that have investigated the molecular modification of D-LIase to improve its thermal stability.In this study,computer-aided tools including FireProt,PROSS,and Consensus Finder were employed to jointly design D-LIase mutants with improved thermostability for the first time.Finally,the obtained five-point mutant M5(N21G/E78P/V58Y/C119Y/K170P)showed high thermal stability and cat-alytic activity.The half-life of M5 at 65◦C was 10.22 fold,and the catalytic efficiency towards 600 g/L of D-fructose was 2.6 times to that of the wild type enzyme,respectively.Molecular dynamics simulation and intramolecular forces analysis revealed a thermostability mechanism of highly rigidity conformation,newly formed hydrogen bonds andπ-cation interaction between and within protein domains,and redistributed surface electrostatic charges for the mutant M5.This research provided a promising D-LIase mutant for the industrial production of D-mannose from D-fructose.

关 键 词：D-lyxose isomerase Thermostability D-MANNOSE Molecular modification 

分 类 号：O62[理学—有机化学]