Change search
ReferencesLink to record
Permanent link

Direct link
Water oxidation energy diagrams for photosystem II for different protonation states, and the effect of removing calcium
Stockholm University, Faculty of Science, Department of Organic Chemistry.
2014 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 24, 11893-11900 p.Article in journal (Refereed) Published
Abstract [en]

The main parts of the water oxidation mechanism in photosystem II have now been established both from theory and experiments. Still, there are minor questions remaining. One of them concerns the charge and the protonation state of the oxygen evolving complex (OEC). Previously, theory and experiments have agreed that the two water derived ligands on the outer manganese should be one hydroxide and one water. In the present study it is investigated whether both of them could be water. This question is addressed by a detailed study of energy diagrams, but in this context it is more conclusive to compare the redox potential of the OEC to the one of Tyr(Z). Both procedures lead to the conclusion that one of the ligands is a hydroxide. Another question concerns the protonation of the second shell His337, where the results are more ambiguous. The final part of the present study describes results when calcium is removed from the OEC. Even though protons enter to compensate the charge of the missing Ca2+, the redox potential and the pK(a) value of the OEC change dramatically and prevent the progress after S-2.

Place, publisher, year, edition, pages
2014. Vol. 16, no 24, 11893-11900 p.
National Category
Organic Chemistry
URN: urn:nbn:se:su:diva-105875DOI: 10.1039/c3cp55329aISI: 000337122000009OAI: diva2:732961


Available from: 2014-07-07 Created: 2014-07-07 Last updated: 2015-09-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Siegbahn, Per E. M.
By organisation
Department of Organic Chemistry
In the same journal
Physical Chemistry, Chemical Physics - PCCP
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 115 hits
ReferencesLink to record
Permanent link

Direct link