通过分子对接和分子动力学模拟等理论方法研究(E)-2-(乙酰胺亚甲基)琥珀酸(E-2AMS)水解酶与其水解底物E-2AMS的结合方式。MM-PBSA结合自由能计算结果和动力学轨迹的统计分析都表明,在E-2AMS与水解酶形成的复合结构中,底物酰胺键采取反式构型在能量上更有利。在这种结合方式中,水解酶活性位点处的关键残基Arg146、Arg167、Tyr168、Arg179和Tyr259与E-2AMS之间形成7条氢键,在催化反应中起到稳定底物的作用;而残基Ile41和Leu107的主链氨基形成"氧负离子洞",能够抵消催化过程中酰胺氧原子上积累的负电荷,有利于反应的顺利进行。
Molecular docking,molecular dynamics(MD) simulation method were used to investigate the binding mode of(E)-2-(Acetamidomethylene)succinate(E-2AMS) hydrolase to its substrate.The results from MM-PBSA binding free energy calculation and the statistical analysis of the MD trajectories all show that the trans-amide configuration of E-2AMS is energetically favourable in the complex structure.In the binding mode,the key residues in the active site of hydrolase,Arg146,Arg167,Tyr168,Arg179 and Tyr259 form seven H-bonds with E-2AMS,which play an important role of stabilizing the substrate in the catalysis reaction.The main-chain amides of Ile41 and Leu107 form an oxyanion hole and offset the negative charge that builds up during catalysis,which is helpful for the catalysis process.