食品与发酵工业2024，Vol.50Issue(12)：17-23,中插1-中插4,11.DOI:10.13995/j.cnki.11-1802/ts.036616
重组木聚糖酶XynH的C/N端及"Thumb"结构对其酶学性质的影响
Effect of C/N terminus and"Thumb"structure of recombinant xylanase XynH on its catalytic properties
摘要
Abstract
Xylanase is widely used in papermaking,feed,energy,food,medicine,and other industries.It is of great significance to use genetic engineering technology to quickly tap xylanase resources suitable for industrial production.Based on bioinformatics analysis,we successfully constructed mutant X-N,X-C,and X-f based on molecular modification of the C/N terminal and"Thumb"structure of xyla-nase XynH.Compared with the proenzyme XynH,the optimal pH of X-N was 5.5,and the other enzymes showed the highest enzyme ac-tivity at pH 5.0.The residual enzyme activity of all mutants and XynH at pH 4.0-6.0 was about 60％,and they had good acid resist-ance.The optimum temperature of X-N(60℃)was increased by 5℃compared with other enzymes.After heat preservation at 55 ℃ for 1 h,the residual enzyme activity of X-N and X-f was higher than that of XynH,and the heat resistance of X-N was better.All the mutants showed weak affinity to beech xylan,but showed higher conversion rate.In this paper,the molecular modification of xylanase by genetic engineering means was used to construct three mutants,all of which showed good acid resistance,the optimal pH of X-N was slightly high-er than that of the original enzyme,and the stability was better at high temperature.N-terminal replacement improves the thermal stability of xylanase,and C-terminal replacement may involve a part of the catalytic domain,resulting in a change in enzyme activity.The modifica-tion of the end of"Thumb"may narrow the cracks at the active site,preventing the entry of the substrate,resulting in a reduction in the catalytic efficiency of the enzyme.The difference between the mutant and the original enzyme in enzymology and the relationship between structure and function revealed by the mutant provide some ideas and strategies for the improvement and application of xylanase.关键词
木聚糖酶/生物信息学/分子改造/酶学性质Key words
xylanase/bioinformatics/molecular modification/enzymatic property引用本文复制引用
朱澳迪,赵婷,徐锦,陈茂彬,方尚玲,李琴..重组木聚糖酶XynH的C/N端及"Thumb"结构对其酶学性质的影响[J].食品与发酵工业,2024,50(12):17-23,中插1-中插4,11.基金项目
国家自然科学基金(31901634) （31901634）
四川省科技厅项目(2022NSFSC1739) （2022NSFSC1739）
湖北工业大学研究生教学改革研究项目资助(校2021057) （校2021057）
