Electroosmosis Dominates Electrophoresis of Antibiotic Transport Across the Outer Membrane Porin F.

We report that the dynamics of antibiotic capture and transport across a voltage-biased OmpF nanopore is dominated by the electroosmotic flow rather than the electrophoretic force. By reconstituting an OmpF porin in an artificial lipid bilayer and applying an electric field across it, we are able to elucidate the permeation of molecules and their mechanism of transport. This field gives rise to an electrophoretic force acting directly on a charged substrate but also indirectly via coupling to all other mobile ions, causing an electroosmotic flow.