Bicarbonate requirement for the donor side of photosystem II

FEBS Letters

Baranov, S.V.¹  Allakhverdiev, S.I.¹  Klimov, V.V.¹  Feyziev, Ya.M.¹ 

[1] Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow region 142292, Russian Federation

关键词: Photosystem II;    Bicarbonate;    Donor side;    Manganese;    BC;    bicarbonate;    DCMU;    3-(3;    4-dichlorphenyl)-1;    1-dimethylurea;    DCPIP;    2;    6-dichlorophenol-indophenol;    DPC;    diphenylcarbazide;    EDTA;    ethylenediaminetetraacetic acid;   

DOI  :  10.1016/0014-5793(95)00327-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Suppression of electron flow (and its subsequent restoration with 3–10 mM NaHCO₃) on the donor side of photosystem II is shown upon either a partial depletion of pea subchloroplast membranes in bicarbonate or the addition of 5–20 μM formate. At higher concentrations (5 mM) formate induces the known ‘bicarbonate effect’ on the acceptor side of photosystem II. In preparations depleted of manganese the restoration of electron flow with 0.1–0.2 μM MnCl₂ (2–4 Mn per photosystem II reaction center) occurs only in the presence of bicarbonate and it is accompanied by an increased functional binding of manganese. Restoration of electron flow with diphenylcarbazide or NH₂OH does not require the addition of NaHCO₃. It is suggested that bicarbonate participates in the formation of the Mn-cluster capable of water oxidation or serves as a substrate for the water-oxidizing center.

【 授权许可】

Unknown