Figure 11.

Absence of Na⁺ current in the inactivation-deficient mutant hERG channel, S631A. (A) Current recorded with the pipette solution containing 135 mM Na⁺ and the bath solution containing 135 mM NMG⁺. (B) Current recorded with the similar condition but with 1 mM K⁺ added to the bath solution (n = 4). The portion of the tail current in the dotted box is expanded in the inset to show the absence of the rising phase of the S631A K⁺ tail current.