Institute of Insect Sciences, College of Agriculture, Yangtze University, Jingzhou, Hubei Province 434025, China.
Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
J Econ Entomol. 2021 Aug 5;114(4):1509-1516. doi: 10.1093/jee/toab095.
Odorant-binding proteins (OBPs) capture and transport semiochemicals to olfactory receptors (OR) and function in the first step in insect olfaction. In the present study, we cloned a full-length cDNA sequence of BodoOBP5 from the insect pest Bradysia odoriphaga (Diptera: Sciaridae). Real-time PCR (qRT-PCR) analysis revealed that BodoOBP5 was expressed at higher levels in female adults than in other developmental stages. In the different tissues, BodoOBP5 was highly expressed in the female antennae, whereas low levels were expressed in the head and the male antennae, expression was negligible in other tissues. The recombinant protein of BodoOBP5 was successfully expressed with a bacterial system. Competitive binding assays with nine host plant volatiles and a putative sex pheromone revealed that purified BodoOBP5 strongly bound to two sulfur compounds (methyl allyl disulfide and diallyl disulfide); the corresponding dissolution constants (Ki) were 10.38 and 9.23 μM, respectively. Molecular docking indicated that Leu99, Leu103, Ala143, Tyr107, Phe142, and Trp144 in the hydrophobic cavity of BodoOBP5 are the key residues mediating the interaction of BodoOBP5 with methyl allyl disulfide and diallyl disulfide. RNAi-based Y-tube olfactometer assay indicated that there is no significant difference in methyl allyl disulfide and diallyl disulfide. The results of this study increase our understanding of the binding of BodoOBP5 with plant volatiles, facilitating the development of novel ways to control B. odoriphaga.
气味结合蛋白（OBPs）捕获和转运半挥发物到嗅觉受体（OR），并在昆虫嗅觉的第一步中发挥作用。在本研究中，我们从昆虫害虫黄地老虎（双翅目：摇蚊科）克隆了全长 cDNA 序列 BodoOBP5。实时荧光定量 PCR（qRT-PCR）分析显示，BodoOBP5 在雌性成虫中的表达水平高于其他发育阶段。在不同组织中，BodoOBP5 在雌性触角中高度表达，而在头部和雄性触角中表达水平较低，在其他组织中表达水平可以忽略不计。重组蛋白 BodoOBP5 已成功在细菌系统中表达。与九种寄主植物挥发物和一种假定性性信息素的竞争性结合测定表明，纯化的 BodoOBP5 强烈结合两种含硫化合物（甲基丙烯二硫醚和二烯丙基二硫醚）；相应的溶解常数（Ki）分别为 10.38 和 9.23 μM。分子对接表明，BodoOBP5 疏水腔中的 Leu99、Leu103、Ala143、Tyr107、Phe142 和 Trp144 是介导 BodoOBP5 与甲基丙烯二硫醚和二烯丙基二硫醚相互作用的关键残基。基于 RNAi 的 Y 型嗅觉计试验表明，甲基丙烯二硫醚和二烯丙基二硫醚之间没有显著差异。本研究结果增加了我们对 BodoOBP5 与植物挥发物结合的理解，有助于开发控制黄地老虎的新方法。
