The nature of the Fe(III) EPR signal from the acceptor‐side iron in photosystem II

FEBS Letters

Vänngård, Tore¹  Styring, Stenbjörn²  Andréasson, Lars-Erik¹  Aasa, Roland¹ 

[1] Department of Biochemistry and Biophysics, Chalmers University of Technology and University of Göteborg, S-412 96 Göteborg, Sweden;Department of Biochemistry, Arrhenius Laboratories, University of Stockholm, S-106 91 Stockholm, Sweden

关键词: Photosystem II;    Acceptor-side iron;    EPR;    (Spinach);    Chl;    chlorophyll;    PS;    photosystem;    PPBQ;    phenyl-p-benzoquinone;   

DOI  :  10.1016/0014-5793(89)80120-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The EPR spectrum at both X- and S-band (3.94 GHz) of the oxidized acceptor-side iron in photosystem II from spinach shows two absorption-type peaks at g = 8.0 and 5.6. The intensities of these peaks have been measured at X-band in the temperature range 2–10 K. All results can be fully described assuming that the EPR spectrum arises from high-spin Fe(III) with D = 1.0±0.3 cm⁻¹ and E/D = 0.10 ±0.01. Quantifications show that the spectrum in our case represents 0.4–0.5 Fe(III) per reaction center. The EPR parameters are consistent with the iron having bicarbonate and/or tyrosine as ligands in addition to four imidazoles.

【 授权许可】

Unknown