The hERG K+ channel S4 domain L532P mutation: Characterization at 37 °C

► The L532P hERG channel mutation was studied at 37 °C. ► The L532P mutation significantly modified activation and inactivation kinetics. ► hERG current elicited by AP voltage clamp was also significantly altered. ► The mutation also decreased channel sensitivity to inhibition by dronedarone. ► Homology modeling provides a structural context for the effects of this mutation.