Data analysis
The slope factor (K) and the midpoint (V1/2) for activation and inactivation were calculated using standard Boltzmann functions: 1/(1 + exp ((V1/2activation – V)/kactivation)) for activation and (1 - C)/(1 + exp ((V – V1/2inactivation)/kinactivation)) + C) for inactivation. V is the voltage. The window current was obtained using equation 1: (1/(1 + exp ((V1/2activation– V)/kactivation)) x ((1 - C)/(1 + exp ((V – V1/2inactivation)/kinactivation)) + C) x 100, which is the probability of having the channel in the open state.