Involvement of bicarbonate in the protonation of the secondary quinone electron acceptor of photosystem II via the non‐haem iron of the quinone‐iron acceptor complex

FEBS Letters

de Bruijn, Steef M.¹  van Rensen, Jack J.S.¹  Tonk, Willem J.M.¹ 

[1] Laboratory of Plant Physiological Research, Agricultural University Wageningen, Gen. Foulkesweg 72, 6703 BW Wageningen, The Netherlands

关键词: Electron transport;    Bicarbonate effect;    Quinone protonation;    Quinone-iron complex;    (Pea chloroplast);    Chl;    chlorophyll;    FeCy;    ferricyanide;    PS;    photosystem;    PQ;    plastoquinone;    QA/QB;    primary/secondary quinone electron acceptor of PS II;    Q-400;    redox group at acceptor side of PS II (high-spinFe2+;   

DOI  :  10.1016/0014-5793(88)81452-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The mechanism of the bicarbonate effect was investigated by monitoring flash-induced pH changes. In control chloroplasts the proton yields exhibit a binary oscillation with a period of four. In CO₂-depleted chloroplasts the binary oscillation disappears and only the period four pattern remains, which can be described by proton liberation in the water-oxidizing system. It is concluded that bicarbonate is involved in the protonation of Q²⁻ _B. The affinity of bicarbonate to its binding site is much lower in the presence of dithionite. It is suggested that bicarbonate exerts its influence through being a ligand for the non-haem iron between Q_A and Q_B.

【 授权许可】

Unknown