Bound electron acceptors of photosystem I Evidence against the identity of redox center A1 with phylloquinone

FEBS Letters

Ziegler, K.¹  Nitschke, W.¹  Lockau, W.¹ 

[1] Institut für Botanik, Universität Regensburg, Universitätsstr. 31, 8400 Regensburg, FRG

关键词: Photosystem I;    P700;    Reaction center;    Phylloquinone;    Electron acceptor;    EPR;    DPPH;    1;    1-diphenyl-2-picrylhydrazyl radical;    P700;    primary electron donor of photosystem I;    PS;    photosystem;    RC I;    P700 reaction center of PS I;   

DOI  :  10.1016/0014-5793(87)81233-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photosystem (PS) I preparations from spinach and from a cyanobacterium contain two molecules of phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone) per photosystem, only one of which is rapidly destroyed by ultraviolet light. In preparations of the core of PS I, the P700 reaction center, both quinone molecules are rapidly destroyed by UV irradiation. Nearly complete destruction does not alter the shape and size of the EPR spectrum of the electron acceptor A₁, which is believed to be phylloquinone. Photooxidation of P700, the primary electron donor of PS I, is also not affected. The results provide strong evidence against the identity of redox center A₁ with the naphthoquinone.

【 授权许可】

Unknown