Requirements for the photoligation of Mn2+ in PS II membranes and the expression of water‐oxidizing activity of the polynuclear Mn‐catalyst

FEBS Letters

Tamura, Noriaki¹  Cheniae, G.M.¹ 

[1] University of Kentucky, Lexington, KY 40546-0091, USA

关键词: Photoactivation Manganese Oxygen evolution Photosynthesis Photosystem II Membrane protein;    DCIPH2;    reduced form of 2;    6-dichlorophenolindophenol;    PS;    photosystem;    VO2;    rate of O2 evolution activity;    TMF;    Triton-membrane fragments;   

DOI  :  10.1016/0014-5793(86)80544-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ligation of Mn²⁺ into the polynuclear Mn-catalyst of water oxidation was shown using PS II membranes depleted of their Mn and the 17, 23 and 33 kDa extrinsic proteins. This process specifically required light and Ca²⁺ concentrations of 5̃0 mM. Evidence was obtained indicating Mn²⁺/Ca²⁺ competition for Ca²⁺ and Mn²⁺ binding sites essential for the photoligation of Mn. Photoligation of Mn did not result in an increase of water oxidation capacity; however, water oxidation capacity was expressed following dark reconstitution minimally with the 33 kDa protein. The results represent the first observation of photoactivation of water oxidation in a system that excludes simple light-driven Mn²⁺ transport across membrane(s).

【 授权许可】

Unknown