Roles of Water in a Gating of Voltage-gated Ion Channels

Abstract

Historical works addressed to elucidating roles of water on a gating process of voltage-gated ion channels were critically reviewed. My recent works on squid sodium channels showed a unified interpretation about these preceding works, i.e. viscosity or osmolarity models. A water-nonelectrolytes mixture solvent affects a voltage-dependent process accompanying gating currents viscosity-dependently and a final step to open osmolarity-dependently. In the latter step, a transient hydration of around 5 water molecules in the pore was essential.