Statistical evaluation of the gating parameters V_1/2 and P_min obtained with internal solution at pH 6.2 without ATP and with 1 mM ATP. Mean values of V_1/2 in the absence and in the presence of 1 mM ATP (n = 36 and n = 21, respectively) (A) and P_min (n = 28 and n = 9, respectively) (B) obtained from the analysis of the overall gating mechanism of hClC-1. Mean values of V_1/2 in the absence and in the presence of 1 mM ATP (n = 8 and n = 5, respectively) (C) and P_min (n = 19 and n = 13, respectively) (D) obtained from the analysis of isolated slow gating mechanism of hClC-1. The values in the absence and in the presence of 1 mM ATP are not significantly different (P > 0.06 using Student's unpaired t test).