Table 2.

Comparison of the effects of mutations at positions 537 and 538 on closed- and open-state stability

537	Parameter		538
		R	K	Q
R		C	WT	O
	ΔG0	2.7	−8.4 (2 s), −10.5 (10 s)	−26.5
	ΔΔG0	13.2		−18.1
	ΔΔG0,NA
K		C	C	O
	ΔG0	−0.9	−2.6	−17.1
	ΔΔG0	9.5	5.8	−8.7
	ΔΔG0,NA	11.5		3.6
Q		C	NA	O
	ΔG0	−3.0	−4.5	−17.7
	ΔΔG0	7.4	3.9	−9.3
	ΔΔG0,NA	11.7		4.9

Letters (C/O) within cells indicate whether the combination of residues at 537 (rows) and 538 (columns) resulted in a stabilization of the closed or open state, relative to WT hERG. For ease of comparison, the mean values for ΔG₀, ΔΔG₀, and ΔΔG_0,NA (in kJ mol⁻¹) are also shown. Refer to Table 1 for full details, including n values and SEM.