Figure 12.

Analysis of V₅₀ at external pH 8 and 6 for Kv11.1 mutants. (A) V₅₀ values are shown for pH 6 and 8 for WT Kv11.1 and Kv11.1 acidic charge-neutralization mutants (dashed lines indicate WT values). The values of V₅₀ were obtained from Boltzmann fits shown in Fig. 11 (A and C–E). (B) ΔV₅₀ (pH 8 to 6) plots for Kv11.1 WT and the S2/S3 acidic charge-neutralization mutants at 50 µM Ca²⁺ and 1 mM Ca²⁺. The dashed line indicates the ΔV₅₀ obtained for WT Kv11.1. Asterisks indicate significant difference with respect to WT: **, P < 0.001; two-tailed nonequal variance Student’s t test.