小菜蛾性信息素結合蛋白與順-9-十四碳烯酸酯作用的分子模擬

趙奇 鄧培淵 李玉華 楊玉珍 楊宗渠 雷志華

摘要：【目的】研究小菜蛾性信息結合蛋白（PxylPBP2）與順-9-十四碳烯酸酯（Z9-14∶Ac）結合的分子動力學模式、結合內驅力及關鍵作用氨基酸，闡明二者識別的分子機制，為小菜蛾性誘劑的研發和小菜蛾防治提供參考依據。【方法】運用YASARA對PxylPBP2進行同源建模，運用AutoDock 4.2進行PxylPBP2與Z9-14∶Ac的空間結構對接，運用YASARA平臺進行分子動力學模擬，運用MMPBSA.py模塊計算PxylPBP2-Z9-14∶Ac復合物的結合自由能，以Amber 12軟件包描述結合關鍵氨基酸，分析PxylPBP2與Z9-14∶Ac的結合模式及相互作用力。【結果】同源建模構建了合理的PxylPBP2空間模型，分子對接結果表明Z9-14∶Ac結合于PxylPBP2結合腔的內部，受體配體間無氫鍵，1.4 ns時對接復合物收斂平衡;PxylPBP2-Z9-14∶Ac結合自由能為-9.76 kcal/mol;Phe22和Ile104的貢獻能量和占總結合自由能的43%。【結論】范德瓦斯力和非極性溶劑力是PxylPBP2與Z9-14∶Ac形成穩定復合物的主要內驅力，能量貢獻最大的兩個關鍵氨基酸（Phe22和Ile104）位于側鏈上。

關鍵詞： 小菜蛾;性信息素結合蛋白（PxylPBP2）;性信息素;分子動力學模擬;能量分解

中圖分類號： S433.4? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 文獻標志碼：A 文章編號：2095-1191（2018）11-2193-05

Molecular simulation of interactions between sex pheromone binding proteins and cis-9-tetradecenoic acid ester

in Plutella xylostella

ZHAO Qi1， DENG Pei-yuan2， LI Yu-hua1， YANG Yu-zhen1，YANG Zong-qu1， LEI Zhi-hua1

（1School of Life Science， Zhengzhou Normal University， Zhengzhou? 450044， China; 2Key Laboratory of Biological Species Resource Research of Zhengzhou， Zhengzhou Normal University， Zhengzhou? 450044， China）

Abstract：【Objective】Molecular dynamics model， internal promoting force and key amino acid of sex pheromone binding proteins（PxylPBP2） and cis-9-tetradecenoic acid ester（Z9-14∶Ac） in Plutella xylostella were studied to illustrate the molecular mechanism of their identification and provide reference for research and development of sex attractant for P. xylostella as well as the prevention and control of P. xylostella. 【Method】Some software was used to analyze the binding modes and interactions of PxylPBP2 and z9-14∶Ac， including homology modeling of PxylPBP2 with YASARA， the space structure docking of PxylPBP2 and Z9-14∶Ac with AutoDock 4.2， molecular dynamics simulation with YASARA platform， calculation of binding free energy of PxylPBP2-Z9-14∶Ac complex with MMPBSA. Py module， and description of binding key amino acids as well as analysis of binding mode and interaction force of PxylPBP2 and Z9-14∶Ac with Amber12 package. 【Result】The reasonable PxylPBP2 space model was constructed by homologous modeling. Molecular docking indicated that the binding of Z9-14∶Ac was in the interior of the PxylPBP2 binding chamber and there was no hydrogen bond between receptor ligands. Docking complex was convergent equilibrium at 1.4 ns. The binding free energy of PxylPBP2-Z9-14∶Ac was -9.76 kcal/mol. The contribution energy sum of Phe22 and Ile104 were 43% of the total binding free energy. 【Conclusion】Van der wals force and non-polar solvation are the principal inner drive to form stable complex between PxylPBP2 and Z9-14∶Ac， two key amino acids（Phe22 and Ile104） contribute the most largest amount of energy and they are located on the side chain.

Key words： Plutella xylostella;sex pheromone binding protein（PxylPBP2）;sex pheromone; molecular dynamics simulation; energy decomposition

0 引言

【研究意義】小菜蛾（Plutella xylostella）是危害十字花科蔬菜的重要鱗翅目菜蛾科害蟲。由于長期使用化學農藥防治小菜蛾，導致該害蟲的抗藥性提高（常曉麗等，2017）。采用性信息素進行小菜蛾生物防治因具有無害、高效的優點而被廣泛采用（陳東旭等，2011）。因此，開展小菜蛾性信息素結合蛋白與性信息素的分子結合模式研究，可為新型性誘劑的研發、修飾和改造等提供重要參考。【前人研究進展】蛾類昆蟲的性信息分子需通過一類小分子量蛋白的攜帶，才能從感器表皮運輸到嗅覺受體神經元，這類小蛋白分子被命名為性信息素結合蛋白（Phe-romone binding proteins，PBPs）（李玉華等，2016）。……