Deactivation of the mutant E130H coexpressed with K _V 7.3. (A and B) Examples of recordings of K⁺ current deactivation at pH_EXT 6.0 (A) and 8.0 (B) following activation pulse of variable duration to +40 mV. Deactivation was driven by a pulse to −105 mV. (C) A double exponential function was fitted to the deactivating currents (not shown). The yielded parameters were used to generate average τ_DEACT–t_PULSE plots at different pH_EXT. (pH_EXT 6.0: n = 5; 7.0: n = 3; 7.4: n = 6; 8.0: n = 5).