Fig. 9.

Effect of the R117M mutation on rat α9α10 receptors. (A) Concentration-response curves to ACh performed in oocytes expressing wild-type (○), α9α10R117M (□), and α9α10W55T/R117M (◊) double-mutant rat receptors. Peak current values were normalized and refer to the maximal peak response to ACh. The mean and S.E.M. of 5–11 experiments per group are shown. (B) Scheme for double-mutant cycle analysis. ΔΔG values corresponding to each mutant are shown. These values were calculated as −RTln(EC₅₀ mutant/EC₅₀ wild type). The coupling parameter, Ω, was calculated as indicated in Materials and Methods.