State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing, China.
Chem Senses. 2012 Feb;37(2):141-50. doi: 10.1093/chemse/bjr084. Epub 2011 Aug 18.
Odorant-binding proteins (OBPs) are found in both insects and vertebrates, and it is believed that they are involved in chemical communication. In this study, we identify and express 2 OBPs from the scarab beetle, Holotrichia oblita Faldermann (Coleoptera: Scarabaeidae). HoblOBP1 shows more similarities with other scarab beetle OBPs, whereas HoblOBP2 is more diverse. N-phenyl-1-naphthylamine (1-NPN) is used as a fluorescent probe in ligand-binding experiment, and results indicate that both HoblOBPs prefer plant volatiles to putative H. oblita sex pheromones. HoblOBP1 shows binding affinity to a wider range of test compounds, but HoblOBP2 displays more specific binding affinity. Cinnamaldehyde and 2,4-di-tert-butylphenol bind to HoblOBP1 can elicit strong electrophysiological responses of the antennae from female H. oblita adults, respectively. Methyl salicylate also shows good affinity to HoblOBP2 and it can elicit moderate electrophysiological responses. Although, β-ionone is one of the ligands of the strongest binding, it elicits a weak electrophysiological response. In the immunocytochemical analysis, we observe that HoblOBP1 and HoblOBP2 are coexpressed in sensilla basiconica and placodea in both sexes.
气味结合蛋白（OBPs）存在于昆虫和脊椎动物中，据信它们参与了化学通讯。在这项研究中，我们从金龟子 Holotrichia oblita Faldermann（鞘翅目：金龟子科）中鉴定并表达了 2 种 OBP。HoblOBP1 与其他金龟子 OBP 具有更多的相似性，而 HoblOBP2 则更加多样化。N-苯基-1-萘胺（1-NPN）被用作配体结合实验中的荧光探针，结果表明，两种 HoblOBPs 均优先结合植物挥发物，而不是假定的 H. oblita 性信息素。HoblOBP1 对更广泛范围的测试化合物具有结合亲和力，但 HoblOBP2 显示出更特定的结合亲和力。肉桂醛和 2,4-二叔丁基苯酚与 HoblOBP1 结合可以分别引起雌性 H. oblita 成虫触角的强烈电生理反应。水杨酸甲酯也对 HoblOBP2 具有良好的亲和力，并能引起适度的电生理反应。尽管β-紫罗兰酮是结合最强的配体之一，但它引起的电生理反应较弱。在免疫细胞化学分析中，我们观察到 HoblOBP1 和 HoblOBP2 在雌雄两性的感觉毛和盘状感觉器中均有共表达。
