Table 1.

Impact of K978C mutation on open probability (P_o), equilibrium gating constant (K_eq), and Gibbs free energy difference for channel opening (ΔG) in the presence and absence of 1.5 mM ATP

	+ATP			−ATP
	Po	Keq	ΔG, kJ/mol	Po	Keq	ΔG, kJ/mol
WT	0.38 ± 0.01	0.61 ± 0.02	1.2 ± 0.1	2.7 × 10−4	2.7 × 10−4	21 ± 0.8
				±8 × 10−5	±8 × 10−5
K978C	0.84 ± 0.03*	6.53 ± 1.57*	−4.3 ± 0.6	0.09 ± 0.01*	0.10 ± 0.02*	5.8 ± 0.5*

K_eq = P_o/(1 − P_o) and ΔG = −RT ln K_eq where R is gas constant and T is temperature. Data are means ± SEMs. Numbers of patches analyzed: three (WT, +ATP), six (WT, −ATP), six (K978C, +ATP), and five (K978C, −ATP).

*Significant differences (P < 0.05) compared with WT (unpaired t test).