Abstract：
Chemical sensing systems are vital in the growth and development of insects. Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important natural enemy of many pests. The molecular mechanism of odorant binding proteins (OBPs) binding with common insecticides is still unknow in O. sauteri. In this study, we expressed in vitro OsauOBP8 and conducted fluorescence competition binding assay to investigate the function of OsauOBP8 to insecticides. The results showed that OsauOBP8 could bind with four common insecticides (phoxim, fenitrothion, chlorpyrifos, deltamethrin). Subsequently, we used molecular docking to predict and obtained candidate six amino acid residues (K4, K6, K13, R31, K49, K55) and then mutated. The result showed that three key residues (K4, K6, R31) play important role in OsauOBP8 bound to insecticides. Our study identified the key binding sites of OsauOBP8 to insecticides and help to better understand the molecular mechanism of OBPs to insecticides in O. sauteri.
摘要：
化学传感系统在昆虫的生长和发育中至关重要。Oriussauteri（Poppius）（半翅目：Anthocoridae）是许多害虫的重要天敌。气味结合蛋白（OBP）与常见杀虫剂结合的分子机制在O.sauteri中仍然未知。在这项研究中,我们在体外表达了OsauOBP8，并进行了荧光竞争结合试验，以研究OsauOBP8对杀虫剂的功能。结果表明，OsauOBP8可以与四种常见的杀虫剂（辛硫磷，非尼托硫磷,毒死蜱,溴氰菊酯）。随后，利用分子对接技术预测并获得候选的6个氨基酸残基(K4、K6、K13、R31、K49、K55),然后进行突变。结果表明，三个关键残基（K4，K6，R31）在与杀虫剂结合的OsauOBP8中起重要作用。我们的研究确定了OsauOBP8与杀虫剂的关键结合位点，并有助于更好地了解OBPs对O.sauteri杀虫剂的分子机制。
