分子对接和动力学模拟提高嗜热蛋白酶PhpI的活力

Molecular Docking and Dynamics Simulation Improving Thermophilic Protease Activity of PhpI

通过分子对接和动力学模拟对嗜热蛋白酶的分子进行改造,确定蛋白酶PH1704(PhpI)定点突变残基,并通过分子生物学实验进行验证.突变体K43C的蛋白酶活力提高了5.8倍.分子动力学模拟结果表明,经过8 ns的动力学模拟后,K43C突变体二级结构由野生型的S2片层(F11-E12-D13)变成环状结构.E12和K43均是活性位点的重要残基,这种变化将导致活性位点的柔性增强,有利于催化反应的发生.

In this study,flexible docking approach was employed to dock the substrate into the active site of protease PH1704（PhpI）,combining with crystal structure to determine the key enzyme,and study on site-mutation in theroy.All parameters were verified by molecular biology experiment.The protease activity of K43C was 5.8 times higher than that of WT.Molecular dynamics simulation reveals that after 8 ns dynamics simulations,the secondary structure of K43C mutant changes from the S2 sheet of WT（F11-E12-D13）to the loop.K43 and E12 are both the important active site residues.The change will enhance the flexibility of active site,and be helpful for catalytic reactions.The new structural and mechanistic insights obtained from molecular docking and dynamics simulation should be valuable for detailed researching of structures and mechanisms of the member of the DJ-1 superfamily.