Fusion of chromatophores from photosynthetic bacteria with a supported lipid layer: characterization of the electric units

FEBS Letters

Laval, Jean-Marc¹  Keller, Sonia²  Leibl, Winfried²  Riou, Yann¹ 

[1] Génie Enzymatique et Cellulaire (CNRS UMR 6022), Université de Technologie de Compiègne, 60205 Compiègne, France;Section de Bioénergétique, CEA Saclay, 91191 Gif-sur-Yvette, France

关键词: Photovoltage;    Membrane potential;    Membrane fusion;    Rhodobacter sphaeroides;    RC;    reaction center;    P;    primary electron donor;    QA;    QB;    primary and secondary quinone acceptor;    OM;    n-octadecyl mercaptan;    ODA;    octadecylamine;    HEPES;    4-(2-hydroxyethyl)-1-piperazine-ethanesulfonic acid;    PMS;    phenazine methosulfate;   

DOI  :  10.1016/S0014-5793(00)02356-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown