Electrogenic proton translocation by the chloroplast cytochrome b 6/f complex reconstituted into phospholipid vesicles

FEBS Letters

Hauska, Günter¹  Hurt, Eduard C.¹  Shahak, Yosepha² 

[1] Intstitut für Botanik, Universität Regensburg, 8400 Regensburg, FRG;Biochemistry Department, Wseizmann Institute of Science, Rehovot 76100, Israel

关键词: Cytochrome b 6/f complex;    Chloroplast;    Electron transport;    Proton translocation;    Membrane potential;    Carbocyanine;    Antimycin A;    diO-C5-(3);    3;    3'-dipentyloxacarbocyanine;    diS-(C3-(5);    3;    3'-dipropylthiadicarbocyanine;    DNP-INT;    2-iodo-6-isopropyl-3-methyl-2';    4;    4'-trinitrodiphenyl ether;    FCCP;    carbonyl cyanide p-trifluoromethoxy-phenylhydrazone;    HEPES;    N-2-hydroxyethylpiperazine-N'-ethanesulfonic acid;   

DOI  :  10.1016/0014-5793(82)81103-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When the cytochrome b ₆/f complex from chloroplasts is incorporated into liposomes, reduction of external plastocyanin by plastoquinol is stimulated under uncoupling conditions. An extra H⁺/e⁻ is ejected from the vesicles during the reaction, in addition to the scalar proton liberated from plastoquinol. This is stimulated by valinomycin/K⁺ and abolished under uncoupling conditions. Furthermore, the formation of a membrane potential during the reaction, negative inside the vesicles, is observed with the help of carbocyanine dyes. We conclude that the cytochrome b ₆/f complex, like the cytochrome bc ₁ from mitochondria, functions as an electrogenic proton translocator.

【 授权许可】

Unknown