Table 1. Effect of R230x mutations on the S4 of KCNQ3 channel.

	n	κ (mV)	z(e)	V1/2 (mV)	ΔV1/2 (mV)	ΔΔG0 (kcal/mol)
WT R230R	13	6.8	3.7	−46.5 ± 3.0
R230K	9	7.5	3.3	−95.0 ± 5.1	48.5 ± 2.2	−3.8 ± 0.5
R230H	8	11.7	2.1	−124.6 ± 6.3	78.1 ± 2.9	−3.9 ± 0.6

Summary of V_1/2, ΔV_1/2, and ΔΔG₀ for WT KCNQ3, KCNQ3-R230K, and KCNQ3-R230H substitutions. V_1/2 is the midpoint of activation, z is the valence describing the voltage sensitivity of activation, and κ is the slope of the activation curve fitted with the Boltzmann Eq. 1 (see Materials and methods). ΔG₀ represents the Gibbs free energy of activation at 0 mV. ΔΔG₀ is calculated as [−F(z^wtV_1/2^wt − z^mutV_1/2^mut)] and is expressed in kcal/mol. Values are means ± SEM; n represents the number of cells analyzed.