Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China.
Key Laboratory of Vegetation Ecology, MOE, Northeast Normal University, Changchun, China.
Sci Rep. 2017 Nov 13;7(1):15374. doi: 10.1038/s41598-017-15538-8.
In this study, the most abundant and antenna-specific odorant-binding protein (OBP) of the elm pest A. quadriimpressum, AquaOBP4, was expressed and purified. The selectivity of AquaOBP4 was investigated by screening against a panel of 40 habitat-relevant compounds. Based on the obtained results, a homologous model of AquaOBP4 was established. This model indicated that AquaOBP4 is highly homologous to DmelOBP LUSH and includes two main binding sites. A docking analysis showed that four of five active ligands bound at Site 1, whereas the other ligand was situated at Site 2. Furthermore, new ligands were docked in the model, and the results of fluorescence-based binding assays of these compounds were highly consistent with the binding conformation and binding affinity predicted by our model. Additionally, three binding odorants derived from elm leaves elicited a strong electroantennogram response and exerted a significant attractive effect on adult A. quadriimpressum. All of the results showed that AquaOBP4 is likely linked to the foraging behavior of A. quadriimpressum. This study provides a new reliable tool for future large-scale compound screenings and revealed several functional chemicals that might aid the development of a better pest management approach for A. quadriimpressum.
在这项研究中，我们表达和纯化了榆绿毛萤叶甲最丰富和具有触角特异性的气味结合蛋白（OBP），即 AquaOBP4。我们通过对 40 种与栖息地相关的化合物进行筛选，研究了 AquaOBP4 的选择性。根据获得的结果，我们建立了 AquaOBP4 的同源模型。该模型表明，AquaOBP4 与 DmelOBP LUSH 高度同源，包含两个主要结合位点。对接分析表明，五个活性配体中的四个结合在 Site 1，而另一个配体位于 Site 2。此外，我们将新的配体对接入模型中，这些化合物的荧光结合分析结果与我们模型预测的结合构象和结合亲和力高度一致。此外，三种源自榆树叶的结合气味物质引发了强烈的触角电位反应，并对成年榆绿毛萤叶甲产生了显著的吸引作用。所有结果表明，AquaOBP4 可能与榆绿毛萤叶甲的觅食行为有关。这项研究为未来的大规模化合物筛选提供了一个新的可靠工具，并揭示了几种可能有助于开发更好的榆绿毛萤叶甲管理方法的功能化学品。
