Cryo-EM Imaging of Kv1.2 Channels with Membrane Potential Applied

Abstract

We use cryo-EM methods to image Kv1.2 potassium channels reconstituted into small (40-50 nm) liposomes. A zero-potential structure at 7.5 angstrom resolution agrees well with the crystal structure of the detergent-solubilized “native” channel complex (S. Long, E. Campbell and R. MacKinnon, 2005). Flux assay results confirm that a negative membrane potential can be established in this system, and we now report results from our imaging these channels in what should be their resting state.