甜菜夜蛾细胞色素P450(CYP9A11)与3种杀虫剂的结合机理研究

细胞色素P450(以下简称CYP)与昆虫的抗药性密切相关。本研究运用AutoDock分子对接技术和分子力学泊松-波尔兹曼表面积法(molecular mechanics Poisson-Boltzmann surface area,MM-PBSA)结合自由能计算方法,分析了甜菜夜蛾CYP9A11与3种杀虫剂结合的作用位点、作用力类型和大小。结果表明:CYP9A11与毒死蜱结合形成两个氢键,有8个氨基酸残基参与形成疏水作用力,二者结合自由能为-3659.80 kJ/mol;CYP9A11与灭多威结合形成5个氢键,有3个氨基酸残基形成疏水作用力,结合自由能为-470.92 kJ/mol;CYP9A11中有7个氨基酸残基与氯氰菊酯结合形成疏水作用力,结合自由能为-473.44 kJ/mol。范德华力是CYP9A11与毒死蜱结合的主要驱动力,极性溶剂化能是CYP9A11与氯氰菊酯和灭多威结合的主要驱动力,这些结果为阐明甜菜夜蛾CYP9A11与3种杀虫剂的结合机理提供了参考。

Study on binding mechanisms of cytochrome P450(CYP9A11) withthree pesticides in Spodoptera exigua

Cytochrome P450 has been well known to play crucial roles in pesticide resistance in insects. In this study, binding sites, type and size of the driving force between cytochrome P450(CYP9A11) in Spodoptera exigua and three pesticides were investigated by AutoDock molecular docking and molecular mechanics Poisson-Boltzmann surface area(MM-PBSA), MM-PBSA free energy calculation. The results showed as follows:when CYP9A11 combined with chlorpyrifos, two hydrogen bonds and eight hydrophobic residues were formed, and the binding free energy was -3659.80 kJ/mol. Five hydrogen bonds and three hydrophobic residues were formed when CYP9A11 combined with methomyl, and the binding free energy was -470.92 kJ/mol. Seven hydrophobic residues formed when CYP9A11 combined with cypermethrin and the binding free energy was -473.44 kJ/mol. The van der Wals force was the main driving force of the docking between CYP9A11 and chlorpyrifos, methomyl and cypermethrin. The main driving force of binding to CYP9A11 was the polar solvation energy. These data could serve as references of illuminating the binding mechanisms of the above mentioned three pesticides with CYP9A11 in S. exigua.