title: Protein reconstitution into freestanding planar lipid membranes for electrophysiological characterization.
abstract: The reconstitution of channel-forming proteins into planar lipid bilayers enables their functional characterization at very low (sometimes below attomolar) concentrations. We describe the three main approaches used in our laboratories (the Mueller-Rudin technique, in which the bilayers contain an organic solvent, the Montal-Mueller or solvent-free technique, and a method for membrane reconstitution via liposome formation), and we discuss their respective advantages and limitations. Despite the differences in the reconstitution procedures, subsequent protein characterization is based on the same electrophysiological technique. A transmembrane electric field is applied, inducing an ion current and allowing conclusions to be drawn on apparent pore sizes, or suggesting functional properties such as channel opening and closing upon ligand binding, pH-induced conformational changes, ion selectivity or substrate specificity.
authors.affiliation: Research Center Borstel, Center for Medicine and Bioscience, Division of Biophysics, Borstel, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gutsmann
authors.affiliation: Membrane Biophysics Group, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Thomas
authors.identifier: 0000000345994582
authors.initials: T
authors.lastname: Heimburg
authors.affiliation: Cavendish Laboratory, University of Cambridge, Cambridge, UK.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Keyser
authors.affiliation: Department of Chemistry, University of Oxford, Oxford, UK.
authors.forename: Kozhinjampara R
authors.initials: KR
authors.lastname: Mahendran
authors.affiliation: 1] Jacobs University Bremen, Bremen, Germany. [2].
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
mesh_terms: D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D050356:Lipid Metabolism / Q000235:genetics*; D018408:Patch-Clamp Techniques; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins