title: Probing the function of ionotropic and G protein-coupled receptors in surface-confined membranes.
abstract: This article reports on recent electrical and optical techniques for investigating cellular signaling reactions in artificial and native membranes immobilized on solid supports. The first part describes the formation of planar artificial lipid bilayers on gold electrodes, which reveal giga-ohm electrical resistance and the insertion and characterization of ionotropic receptors therein. These membranes are suited to record a few or even single ion channels by impedance spectroscopy. Such tethered membranes on planar arrays of microelectrodes offer mechanically robust, long-lasting measuring devices to probe the influence of different chemistries on biologically important ionotropic receptors and therefore will have a future impact to probe the function of channel proteins in basic science and in biosensor applications. In a second part, we present complementary approaches to form inside-out native membrane sheets that are immobilized on micrometer-sized beads or across submicrometer-sized holes machined in a planar support. Because the native membrane sheets are plasma membranes detached from live cells, these approaches offer a unique possibility to investigate cellular signaling processes, such as those mediated by ionotropic or G protein-coupled receptors, with original composition of lipids and proteins.
authors.affiliation: Laboratory of Physical Chemistry of Polymers and Membranes, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Danelon
authors.forename: Samuel
authors.initials: S
authors.lastname: Terrettaz
authors.forename: Olivier
authors.initials: O
authors.lastname: Guenat
authors.forename: Milena
authors.initials: M
authors.lastname: Koudelka
authors.forename: Horst
authors.initials: H
authors.lastname: Vogel
mesh_terms: D002462:Cell Membrane / Q000502:physiology; D017097:Electric Impedance; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D007473:Ion Channels / Q000737:chemistry; D008051:Lipid Bilayers / Q000378:metabolism*; D008563:Membrane Lipids / Q000737:chemistry; D008566:Membranes / Q000378:metabolism*; D018613:Microscopy, Confocal; D036103:Nanotechnology / Q000295:instrumentation; D011956:Receptors, Cell Surface / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled / Q000502:physiology*; D015398:Signal Transduction; D013057:Spectrum Analysis
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers; D008563:Membrane Lipids; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D006046:Gold