Table 1.

hERG channel activation (V_½ and slope factor) values in HEK-293 cell and neonatal mouse cardiomyocyte expression systems

	WT hERG		N470D hERG		G601S hERG		ΔY475 hERG
	V½, mV	k, mV/e-fold change	V½, mV	k, mV/e-fold change	V½, mV	k, mV/e-fold change	V½, mV	k, mV/e-fold change
Neonatal mouse cardiomyocytes	−14.6 ± 3.0	5.9 ± 0.3	−43.6 ± 2.6	6.3 ± 0.6	−14.4 ± 2.1	5.3 ± 0.5	−25.9 ± 2.1	6.0 ± 0.1
HEK-293 cells	−11.3 ± 0.3	6.9 ± 0.2	−40.4 ± 1.2	6.7 ± 0.4*	−16.5 ± 6.4	6.9†	−30 ± 0.3	6.1 ± 0.2

Values are means ± SE. V_½, voltage at which peak tail current is half-maximal; k, slope factor; WT, wild type. G601S and N470D tail currents were recorded after pharmacological correction by E4031 followed by drug washout. Data for N470D and G601S hERG in human embryonic kidney (HEK)-293 cells are from published literature (*Ref. 45 and †Ref. 31).