Direct observation of the immediate electron donor to chlorophyll‐a + II (P‐680+) in oxygen‐evolving photosystem II complexes Resolution of nanosecond kinetics in the UV

FEBS Letters

Schlodder, E.¹  Gerken, S.¹  Brettel, K.¹  Witt, H.T.¹ 

[1] Max-Volmer-Institut für Biophysikalische und Physikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-1000 Berlin 12, Germany

关键词: Oxygen evolution;    Photosystem II;    P-680;    Electron transfer;    Absorbance difference spectroscopy;    (Synechococcus sp.);    Chl;    chlorophyll;    D;    electron donor to Chl-a + II in O2-evolving PS II;    FWHM;    full width at half maximum;    Mes;    4-morpholineethanesulphonic acid;    PS II;    photosystem II;    QA;    primary quinone acceptor of PS II;    S;    water oxidizing enzyme system;    Z;    electron donor to Chl-a + II in PS II devoid of its O2-evolving capability;   

DOI  :  10.1016/0014-5793(87)80322-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Flash-induced absorption changes in the UV have been monitored with nanosecond time resolution in oxygen-evolving photosystem II complexes from Synechococcus sp. At 260 nm, the oxidation of the immediate donor to Chl-a ⁺ _II (P-680⁺) in the 10–500 ns range could be observed directly. The difference extinction coefficient for its oxidation is estimated to be 6000–8000 M⁻¹·cm⁻¹ at 260 nm. The observed kinetics for the oxidation of the donor is identical with the reduction kinetics of Chl-a ⁺ _II as monitored at 824 nm. At 320 nm, the reduction of Q_A was found to be faster than 1 ns.

【 授权许可】

Unknown