Real-time imaging of fast conformational dynamics of ion channel gating with plasmonic nano-antennas

Rapid transmission of signals in the CNS is mediated by the gating of neurotransmitter and voltage-gated ion channels. While these signaling proteins likely sample multiple conformations as they transition between functional states (closed, open, inactivated), the mechanisms underlying these transitions remain poorly understood. Integrating expertise in plasmonics, single-molecule spectroscopy and neuroscience we will perform simultaneous single molecule fluorescence with electrophysiology recordings of Kv1.2 ion channels to image conformational changes and gating dynamics at submillisecond time scales. We will develop plasmonic nanostructures as a platform to examine in situ ion channel dynamics using single-molecule FRET. Cells will be cultured directly on nanostructured arrays, and patch clamp methods will be used to control channel gating while simultaneously monitoring receptor conformation. Nanoscale portions of the plasma membrane containing labeled ion channels will be isolated within plasmonic structures, resulting in fluorescence enhancement. This integrated approach will provide the first correlation between functional and conformational states of single ion channels.