Figure 2.

Effect of alanine substitutions of F1817 and Y1824 in IVS6 on the voltage-dependence of fast (A) and slow (B) inactivation of BgNa_v1-1a channels. Fast inactivation was measured with 200-ms conditioning pulses to potentials ranging from -100 to 40 mV from a holding potential of -60 mV (BgNa_v1-1a and BgNa_v1-1a^Y1824A) or -65 mV (BgNa_v1-1a^F1817A) followed immediately by 20-ms test pulses to -10 mV. Slow inactivation was measured using 60-s conditioning pulses to potentials ranging from -140 to 10 mV followed by hyperpolarizing pulses to -120 mV (100 ms) to remove any fast inactivation and 20-ms test pulses to -10 mV. Conditioning and test pulses were applied from holding potentials of -60 mV (BgNa_v1-1a and BgNa 1-1a^Y1824A) or -65 mV (BgNa_v1-1a^{F1817A v}). Currents were normalized to the amplitude of the largest recorded current.