Table 1.

Summary of slope and potentials for half-maximal activation of WT and mutant HERG channels determined from tail current amplitudes fit with Boltzmann function

HERG channel	V0.5, mV	k, mV	n
WT HERG	−16.7  ± 1.3	7.8  ± 0.5	3
T623A	−25.1  ± 1.6	6.7  ± 0.3	4
V625A	−28.9  ± 1.3	7.9  ± 0.3	5
G648A	−33.4  ± 2.5	7.8  ± 0.1	4
Y652A	−18.0  ± 1.4	9.1  ± 1.1	7
F656A	−26.1  ± 2.8	8.2  ± 0.6	3

V_0.5, potential of half-maximal activation; k, slope of the activation curve; n, number of oocytes. Currents were activated with 5-s depolarizations from a holding potential of −90 mV.