Kinetics of the oxidation—reduction reactions of the photosystem II quinone acceptor complex, and the pathway for deactivation

FEBS Letters

Crofts, Antony R.¹  Robinson, Howard H.¹ 

[1] Department of Physiology and Biophysics, University of Illinois at Urbana-Champaign, 524 Burrill Hall, 407 South Goodwin Avenue, Urbana, IL 61801, USA

关键词: Photosynthesis;    Fluorescence yield;    Kinetics;    Plastoquinone;    Two-electron gate;    Semiquinone;    PS II;    photosystem II;    QA;    the primary quinone acceptor of PS II;    QB;    the secondary quinone acceptor of PS II;    DCMU;    3-(3;    4-dichlorophenyl)-1;    1-dimethylurea;    Hepes;    H-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid;    chl;    chlorophyll;   

DOI  :  10.1016/0014-5793(83)80152-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When the photosystem II quinone acceptor complex has been singly reduced to the state Q_AQ⁻ _B, there is a 22 s half-time back-reaction of Q⁻ _B with an oxidized photosystem II donor (S₂), directly measured here for the first time. From the back-reaction kinetics with and without inhibitors, kinetic and equilibrium parameters have been estimated. We suggest that the state Q_AQ⁻ _B of the complex is formed by a second-order reaction of vacant reaction centers in the state Q⁻ _A with plastoquinone from the pool, and discuss the physico-chemical parameters involved.

【 授权许可】

Unknown