  Bubbles in ion channel proteins have been proposed to be the bistable gates
that control current flow. Gating currents associated with channel gating would
then be an electrical signature of bubble breaking and formation, arising from
the change in dielectric coefficient as the bubble breaks or forms. A bubble
would have a dielectric coefficient of 1. A filled bubble would have a
dielectric coefficient (say) between 30 and 80. Transporters, pumps, and
channels would be expected to have gating currents.
