The DMPC lipid phase transition influences differently the first and the second electron transfer reactions in bacterial reaction centers

FEBS Letters

Taly, Antoine¹  Sebban, Pierre¹  Baciou, Laura¹ 

[1] Centre de Génétique Moléculaire, Bâtiment 24, CNRS, 91198 Gif-sur-Yvette, France

关键词: Liposome;    Membrane protein;    Reaction center;    Electron transfer;    RC;    reaction center;    DMPC;    dimyristoylphosphatidylcholine;    P;    primary electron donor (bacteriochlorophyll dimer);    QA;    primary quinone;    QB;    secondary quinone;   

DOI  :  10.1016/S0014-5793(02)03635-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photosynthetic reaction centers (RCs) from Rhodobacter sphaeroides were incorporated in dimyristoylphosphatidylcholine (DMPC) liposomes. The first and second electron transfer rates (k _AB(1) and k _AB(2), respectively) between the first and the second quinone electron acceptors have been measured as a function of temperature, across the phase transition of DMPC (23°C). The Eyring plots of k _AB(1) display straight lines. In contrast, the Eyring plots for k _AB(2) in proteoliposomes show a break at about 23.5°C. This physical discrimination between the two electron transfer reactions demonstrates that the stiffness of the lipid environment of the RCs and/or the protein–protein interactions influence the parameters governing k _AB(2), but not the gating process limiting k _AB(1).

【 授权许可】

Unknown