When reconstituted into planar bilayer lipid membranes, OmpF can be closed (or “gated”) by high electric fields. We discover that:

	channel gating is sensitive to the type of cations in the membrane-bathing solution according to their position in the Hofmeister series;
	channel gates to a “closed” state that is represented by a set of multiple sub-conformations with at least three distinctly different conformations contributing to the closed-state conductance histogram.

Taken together with the nearly symmetric response to the applied voltage of changing polarity and the hysteresis phenomena reported previously by others and reproduced here, these findings suggest that the voltage-induced closure of the OmpF channel is a consequence of reversible denaturation of the protein by the high electric field. [PDF]