A rational design for improving the trypsin resistance of aflatoxin-detoxifizyme (ADTZ) based on molecular structure evaluation

摘要：

　　The resistance of feed enzymes against proteases is crucial in livestock farming.In this study,the trypsin resistance of aflatoxin-detoxifizyme(ADTZ)is improved.ADTZ possesses 72 lys/arg residue sites,45 of which are scattered on the outermost layers of the molecule(RSA≥ 25%).These 45 lys/arg sites could be target sites for trypsin hydrolysis.By considering shape-matching(including physical and secondary bond interactions)and the “induced fit-effect”,we hypothesized that some of these lys/arg sites are vulnerable to trypsin.A protein-protein docking simulation method was used to avoid the massive computational requirements and to address the intricacy of selecting candidate sites,as candidate site selection is affected by space displacement.Optimal mutants(K244Q/K213C/K270T and R356E/K357T/R623C)were predicted by computational design with protein folding energy analysis and molecular dynamics simulations.A trypsin digestion assay was performed,and the mutants displayed much higher stability against trypsin hydrolysis compared to the native enzyme.Moreover,temperature-and pH-activity profiles revealed that the designed mutations did not affect the catalytic activity of the enzyme.

关键词： Aflatoxin-detoxifizyme Trypsin resistance Rational design Molecular simulation

作者: Yuxin Qiu Xiyang Wu Chunfang Xie Yadong Hu Daling Liu Yi Ma Dongsheng Yao

作者单位: Institute of Microbial Biotechnology,Jinan University,Guangzhou City,Guangdong Province 510632,China Institute of Microbial Biotechnology,Jinan University,Guangzhou City,Guangdong Province 510632,China National Engineering Research Center of Genetic Medicine,Guangzhou City,Guangdong Province 510632,Ch Institute of Microbial Biotechnology,Jinan University,Guangzhou City,Guangdong Province 510632,China

会议类型: 国内会议

会议名称: 第九届国际分子模拟与信息技术应用学术会议(ICMS&I2018)

会议地点: 太原

会议语种:英文

页码: 339-347

在线出版日期: 2018-05-01（万方平台首次上网日期，不代表论文的发表时间）