Neutralization of S4 charges reduces the effective gating charge in monomeric Hv channels. (A) The current during up and down voltage ramps for monomeric R255N ΔNΔC Ci-Hv1 channels. (B) The calculated conductance (I/(V − E_rev)) during up and down voltage ramps for monomeric R258N ΔNΔC Ci-Hv1 channels. The conductance is similar during the up and down ramps, showing that the ramp speed is slow enough to estimate the steady-state conductance. (C) Effective gating charge (zδ) estimated from the limiting slope for charge-neutralized and WT Hv channels in dimeric (red) or monomeric (teal) form (ΔNΔC; see Materials and methods; n = 4). Error bars are SEM.