Ryanodine receptors (RyRs) are homotetrameric intracellular calcium (Ca²⁺) release channels responsible for excitation–contraction coupling of muscle cells. Diamide insecticides specifically act on RyRs of Lepidoptera and Coleoptera pests and are safe for nontargeted organisms, generating big worldwide sales. Despite their popularity, several devastating agricultural pests have been reported to be resistant to them because of mutations in a small transmembrane region of their RyRs, hinting a binding pocket nearby. A potential solution to overcome resistance is to develop new insecticides targeting different binding sites in pest RyRs. Based on a high-resolution crystal structure of diamondback moth (DBM) RyR N-terminal domain (NTD) determined by our group, we carried out extensive structure-based insecticide screening targeting the intersubunit interface. We identified eight lead compounds that selectively target the open conformation of DBM RyR, which are predicted to act as channel activators similar to diamide insecticides. Binding mode analysis shows selective binding to a hydrophobic pocket of DBM NTD-A but not to the pocket of its mammalian counterpart. We tested three available compounds on the HEK293 cell lines stably expressing DBM or mammalian RyR, one of which shows good potency and selectivity against DBM RyR. The insecticidal effect of the compound was also confirmed using fruit flies. The detailed binding mode, toxicity, absorption, distribution, metabolism, and excretion, and reactivity of the compound were predicted by bioinformatic methods. Together, our study lays a foundation for developing a new class of selective RyR-targeting insecticides to control both wild-type and resistant pests.

中文翻译：

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发现潜在的特定于鳞翅目Ryanodine受体的绿色杀虫剂。

Ryanodine受体（RyRs）是同型四聚体细胞内钙（Ca ²⁺）释放负责肌肉细胞兴奋-收缩偶联的通道。二酰胺类杀虫剂专门作用于鳞翅目和鞘翅目害虫的RyRs，对非目标生物是安全的，在全球范围内都有很大的销售量。尽管它们很流行，但据报道，由于其RyR的一个小跨膜区域发生突变，一些毁灭性农业害虫对其具有抗性，暗示附近有一个结合口袋。克服抗性的潜在解决方案是开发针对害虫RyRs中不同结合位点的新型杀虫剂。基于由我们小组确定的小菜蛾（DBM）RyR N末端结构域（NTD）的高分辨率晶体结构，我们针对亚基间界面进行了广泛的基于结构的杀虫剂筛选。我们确定了八种主要针对DBM RyR开放构象的先导化合物，这些化合物预计将充当类似于二酰胺杀虫剂的通道激活剂。结合模式分析显示与DBM NTD-A疏水口袋的选择性结合，但不与其哺乳动物对应口袋的结合。我们在稳定表达DBM或哺乳动物RyR的HEK293细胞系上测试了三种可用的化合物，其中一种显示出对DBM RyR的良好效能和选择性。还使用果蝇证实了该化合物的杀虫作用。通过生物信息学方法预测了该化合物的详细结合方式，毒性，吸收，分布，代谢和排泄以及反应性。一起，