Figure 8.

Comparison of V₅₀ at pH 6 and 8 for Kv12.1 mutants. (A) V₅₀ values are shown for pH 6 and 8 for WT and mutant Kv12.1 channels; values are taken from the single Boltzmann fits shown in Figs. 5–7. Dashed lines indicate the WT V₅₀ values for pH 6 and 8. (B) Comparison of the pH 8 to 6 V₅₀ shift for WT and mutant Kv12.1 channels. Shifts were calculated as a difference: ΔV₅₀ = V₅₀ (pH = 6) − V₅₀ (pH = 8). The dashed line indicates the ΔV₅₀ for Kv12.1 WT. Data points show mean ± SEM. Two-tailed nonequal variance Student’s t test was used to judge significance of the differences in ΔV₅₀; asterisks indicate significant difference from WT: **, P < 0.001; and *, P < 0.05.