| Abstract: | The conductance of rabbit sarcoplasmic reticulum K+ channels incorporated into artificial bilayers of varying lipid composition was measured at different K+ and proton concentrations. Protons competitively inhibit the K+ conductance with a Ki of 0.5 microM. In negatively charged membranes, the conductance is well described by Gouy-Chapman-Stern theory modified to include the inhibitory effect of protons of the conductance and assuming that the channel mouth is isolated by 5-10 A from bilayer surface. |
