The rates of proton uptake and electron transfer at the reducing side of photosystem II in thylakoids

FEBS Letters

Junge, Wolfgang¹  Haumann, Michael¹ 

[1]Biophysik, FB Biologie/Chemie, Universität Osnabrück, D-49069 Osnabrück, Germany

关键词: Photosynthesis;    Photosystem II;    Electron transfer;    Proton uptake;    Quinone;    Electrostatics;    BSA;    bovine serum albumine;    Chl;    chlorophyll;    Fe;    nonheme iron;    NR;    Neutral red;    P700;    primary donor of photosystem I;    PR;    phenol red;    PSI;    photosystem I;    PSII;    photosystem II;    QA;    bound primary quinone electron acceptor of photosystem II;    QB;    secondary quinone electron acceptor of photosystem II.;   

DOI  :  10.1016/0014-5793(94)00495-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Proton and electron transfer at the reducing side of photosystem II of green plants was studied under flashing light, the former at improved time resolution by using Neutral red. The rates of electron transfer within Q_AFeQ_B were determined by pump-probe flashes through electrochromic transients. The extent of proton binding was about 1 H⁺/e⁻. The rates of proton transfer were proportional to the concentration of Neutral red (collisional transfer), whereas the rates of electron transfer out of Q⁻ _A and from Q_AFeQ⁻ _B to the cytochrome b ₆ f complex were constant. The half-rise times of electron transfer (τ_e) and the apparent times of proton binding (τ_h) at 30 μM Neutral red were: Q⁻ _A ⇒ Fe^IIIQ_B (τ_e ⩽ 100 μs, τ, 230 μs); Q⁻ _A ⇒ Fe^IIQ_B (τ_e = 150 μs, τ_h = 760 μs); and Q⁻ _A ⇒ Fe^IIQ⁻ _B (τ_e = 620 μs, τ_h = 310 μs).

【 授权许可】

Unknown