Jia Qian, Zeng Hui, Zhang Jinbing, Gao Shangfang, Xiao Nan, Tang Jing, Dong Xiaolin, Xie Wei
MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510006, China.
Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China.
Insects. 2021 Jul 1;12(7):602. doi: 10.3390/insects12070602.
F. is a generalist herbivore and one of the most important economic pests feeding on about 300 host plants in many Asian countries. Specific insect behaviors can be stimulated after recognizing chemicals in the external environment through conserved chemosensory proteins (CSPs) in chemoreceptive organs, which are critical components of the olfactory systems. To explore its structural basis for ligand-recognizing capability, we solved the 2.3 Å crystal structure of the apoprotein of CSP8 (SlCSP8). The SlCSP8 protein displays a conserved spherical shape with a negatively charged surface. Our binding assays showed that SlCSP8 bound several candidate ligands with differential affinities, with rhodojaponin III being the most tightly bound ligand. Our crystallographic and biochemical studies provide important insight into the molecular recognition mechanism of the sensory protein SlCSP8 and the CSP family in general, and they suggest that CSP8 is critical for insects to identify rhodojaponin III, which may aid in the CSP-based rational drug design in the future.
F.是一种多食性食草动物，也是许多亚洲国家最重要的经济害虫之一，以约300种寄主植物为食。通过化学感受器官中保守的化学感受蛋白（CSPs）识别外部环境中的化学物质后，特定的昆虫行为会被激发，这些化学感受器官是嗅觉系统的关键组成部分。为了探究其识别配体能力的结构基础，我们解析了CSP8（SlCSP8）脱辅基蛋白的2.3 Å晶体结构。SlCSP8蛋白呈现出保守的球形，表面带负电荷。我们的结合试验表明，SlCSP8以不同亲和力结合几种候选配体，其中红景天苷III是结合最紧密的配体。我们的晶体学和生化研究为感官蛋白SlCSP8以及整个CSP家族的分子识别机制提供了重要见解，并且表明CSP8对昆虫识别红景天苷III至关重要，这可能有助于未来基于CSP的合理药物设计。
