Insect Ryanodine Receptor: Distinct but Coupled Insecticide Binding Sites for [N‑C3H3]Chlorantraniliprole, Flubendiamide, and [3H]Ryanodine

Radiolabeled anthranilic diamide insecticide [N-C3H3]­chlorantraniliprole was synthesized at high specific activity. It was compared with phthalic diamide insecticide flubendiamide and [3H]­ryanodine in radioligand binding studies with house fly muscle membranes to provide the first direct evidence with a native insect ryanodine receptor that the major anthranilic and phthalic diamide insecticides bind at different allosterically coupled sites, i.e., there are three distinct Ca2+-release channel targets for insecticide action.