Odorant binding proteins (OBPs) are critical components in insect olfactory systems where they bind, solubilize and transport odorant molecules to receptors. Here, we cloned three OBPs (PxylGOBP1, PxylGOBP2 and PxylOBP24) from the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous crops. These three OBPs were expressed in Escherichia coli as recombinant proteins, purified and characterized by fluorescence binding assays with 39 ligands including sex pheromone and plant‐derived chemical compounds. PxylGOBP1 and PxylGOBP2 showed significantly different binding affinities to theses ligands, suggesting distinct binding preferences of these two general odorant binding proteins. PxylOBP24 showed no or extremely low binding activities to selected ligands, suggesting it may be involved in non‐olfactory functions. Circular dichroism spectral results demonstrated that PxylGOBP1 and PxylGOBP2 shared similar secondary structures while PxylOBP24 was significantly different. This study improves our knowledge of insect OBPs, which will assist in a better understanding of insect olfactory system and developing more environmentally friendly pest control strategies for P. xylostella.

中文翻译：

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小菜蛾小菜蛾三种气味结合蛋白的表达，纯化和鉴定。

气味结合蛋白（OBP）是昆虫嗅觉系统中的重要组成部分，它们在其中结合，溶解并将气味剂分子运输到受体。在这里，我们从小菜蛾小菜蛾Plutella xylostella克隆了三个OBP（PxylGOBP1，PxylGOBP2和PxylOBP24），这是十字花科作物最具破坏力的害虫之一。这三个OBPs在大肠杆菌中表达作为重组蛋白，可通过39种配体（包括性信息素和植物衍生的化合物）的荧光结合测定法进行纯化和表征。PxylGOBP1和PxylGOBP2对这些配体表现出明显不同的结合亲和力，表明这两种一般的气味结合蛋白具有独特的结合偏好。PxylOBP24对选定的配体没有显示或极低的结合活性，表明它可能参与了非嗅觉功能。圆二色性光谱结果表明，PxylGOBP1和PxylGOBP2具有相似的二级结构，而PxylOBP24有显着差异。这项研究提高了我们对昆虫OBP的了解，这将有助于更好地了解昆虫的嗅觉系统，并为昆虫开发更环保的害虫控制策略。小菜蛾。