title: Fusion of chromatophores from photosynthetic bacteria with a supported lipid layer: characterization of the electric units.
abstract: Direct electrometric measurements of membrane potential changes are a valuable tool for study of vectorial transfer of electrons, protons, and ions. Commonly model membrane systems are created by fusion of lipid/protein vesicles with lipid-coated thin films. We characterized the electric units resulting from this process using chromatophores from the purple bacterium Rhodobacter sphaeroides and either a Mylar film or a planar modified gold electrode as support. Investigation of the shunting activity of the ionophore gramicidin on the flash-induced potential change demonstrates fusion of individual chromatophores to form independent 'blisters', which preserve an interior aqueous compartment. Under current-clamp conditions the photovoltage follows the change of the membrane potential of the individual blisters.
authors.affiliation: Section de Bioénergétique, CEA Saclay, France.
authors.forename: S
authors.initials: S
authors.lastname: Keller
authors.forename: Y
authors.initials: Y
authors.lastname: Riou
authors.forename: J
authors.initials: J
authors.lastname: Laval
authors.forename: W
authors.initials: W
authors.lastname: Leibl
mesh_terms: D020130:Bacterial Chromatophores / Q000502:physiology* / Q000648:ultrastructure; D004594:Electrophysiology / Q000379:methods; D007425:Intracellular Membranes / Q000502:physiology; D008027:Light; D008561:Membrane Fusion; D008564:Membrane Potentials; D018408:Patch-Clamp Techniques / Q000295:instrumentation; D010788:Photosynthesis; D012242:Rhodobacter sphaeroides / Q000502:physiology*