Studies on Structure and Mechanism of Photosynthetic Water Oxidation

摘要: The key evolutionary step in the exploitation of solar radiation by photosynthetic water cleavage was “invention” a molecular device that enables light-driven oxidation two molecules to oxygen. Two indispensable prerequisites are required perform oxidation: (a) generation sufficiently oxidising redox equivalents and (b) cooperation four equivalents. This goal achieved about 2-3 billion years ago at level prokaryotic photosynthesising organisms. result multimeric pigment protein complex referred as Photosystem II (PS II) is anisotropically incorporated thylakoid membrane acts water-plastoquinone oxidoreductase (for recent review see ref. [1]). overall reaction PS leading formation bound plastoquinol (PQH2) release oxygen into atmosphere comprises three sequences: i) photooxidation special Chla component (symbolised P680) subsequent stabilisation primary charge separation rapid electron transfer from Pheo-· specially plastoquinone-9 molecule (QA) [2]); ii) strongly holes via sequence univalent steps manganese containing unit, (WOC) leads protons reviews refs. [3-5]), iii) reducing (electrons) (QB), transiently pocket (QB-site). PQH2 [6, 7]).