Figure 5.

Effect of mutation on channel activation and deactivation kinetics. Activation kinetics were derived from the rising phase of currents evoked by depolarizing pulses (−20 to +80 mV), lasting 300 ms from a holding potential of −80 mV. Deactivation kinetics were derived from tail currents recorded at potentials −20 to −80 mV (pre-pulse potential +20 mV). Normalized and superimposed representative Kv1.1 (a) and Kv1.1/1.2 (d) activating currents were recorded at +20 mV, and Kv1.1 (b) and Kv1.1/1.2 (e) deactivating currents recorded at −50 mV. Activating and deactivating current traces were fitted with double and single exponential functions, respectively. Time constants of the currents were plotted as a function of membrane potential for Kv1.1 (c) and Kv1.1/1.2 (f) channels. Plots show that mutation results in slower activation but faster deactivation. The data points are mean ± SE of 8 cells.