Water oxidation in photosystem II: oxygen release, proton release and the effect of chloride
2009 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, no 45, 10063-10068 p.Article in journal (Refereed) Published
Recent reviews on quantum chemical studies of water oxidation in photosystem II have focused on the energetics of O-O bond formation, including the energies of the different S-states. In the present paper, this is extended by discussing the release pathways for dioxygen and protons from the oxygen evolving complex. Based on recent X-ray structures, the effect of adding chloride has also been investigated. Unlike most earlier suggestions, a small, but probably significant, electrostatic effect of adding chloride is found for the higher S-states. For releasing dioxygen in the S-4-state, entropy plays a major role. The suggested pathway for proton release in the S-1 to S-2 transition involves key roles of an outside water and the motion of Asp170. An electron transfer between manganese centra during proton release is also found to be important for a low barrier.
Place, publisher, year, edition, pages
2009. no 45, 10063-10068 p.
o bond formation, evolving complex, resolution, mechanism, channels
IdentifiersURN: urn:nbn:se:su:diva-59651DOI: 10.1039/b909470aISI: 000271714800016OAI: oai:DiVA.org:su-59651DiVA: diva2:432251
authorCount :12011-08-022011-07-052011-08-02Bibliographically approved