A novel mechanism for voltage control of channel conductance.

Many channel-formers can exist in conformational states with varying degrees of conductance. When the difference in the energy level between states is voltage dependent the result is a voltage-dependent channel. This voltage-dependence is usually attributable to the movement of charges or alignment of dipoles associate with channel-former. This paper presents a simpler mechanism by which the energy difference can be voltage dependent without the need for charge movement or dipole alignment. The voltage dependent energy difference between the high and low conducting states can arise from a change in electrical potential at a fixed charge located on the walls lining the pore (or field at a dipole fixed within the pore) which occurs as a result of the conformational change. This mechanism takes advantage of structural features normally found in channel formers and local changes resulting from channel opening and closing to generate the energy difference needed for voltage-dependence.