Fold changes in activation and deactivation time constants and the V_1/2 of activation for I_Ks resulting from mutations in S3. Fold change from WT for activation time constants at +20 mV and deactivation time constants at −50 mV for all S3 mutants. See Materials and methods for calculation of time constants. Change in the V_1/2 of activation from WT for each of the S3 mutants is shown.