Functional Characterization of Ion Channels in Planar Lipid Bilayers

Ion channels form transmembrane protein pores allowing ion fluxes across biological membranes. Their function is indispensable for normal homeostasis; therefore, channelopathies lead to a large variety of diseases affecting almost all tissues and organs. In the last decades, the structure of hundreds of ion channels has been solved. In the majority of the solved structures the pore is closed, and for most of the protein preparations used in these studies, currently little data is available to support that the purified protein forms a functional ion channel capable of gating. Planar lipid bilayer technique is a powerful tool to address this issue. Purified ion channel protein is incorporated into a membrane bilayer separating two compartments in an experimental chamber. Channel currents are recorded between the two sides. Such setup allows characterization of gating and permeation properties of ion channels unbiased by auxiliary components present in native membranes. The planar lipid bilayer technique is thus discussed herein together with the robust protein expressing BacMam system.