Cel Photosynthetic water oxidation by green plants and cyanobacteria is the source of the terrestrial oxygen atmosphere and of oxygenic life. It is driven by photosystem II (PSII) and catalysed by a tetramanganese cluster; the multi-subunit host protein is incorporated in the thylakoid membrane. In addition to generating redox pairs (dioxygen and quinole) the protolytic reactions, which are intimately coupled with vectorial electron transfer, generate protonmotive force for the synthesis of ATP, the multipurpose energy supply of cells. Water oxidation to molecular oxygen proceeds by a sequence of four univalent oxidations of the manganese centre. It is generally agreed that the actual reaction with (bound) water proceeds by two consecutive two-electron steps if not by a single concerted four-electron transfer. This poses considerable kinetic and thermodynamic problems as theoretically worked out. The topic of this project is the electrostatic balance of the four univalent steps and of the final concerted multi-electron reaction. The two western laboratories have pioneered time-resolved spectroscopic detection (ns to ms time range) of protolytic reactions and (vectorial) electron transfer between PS II and the manganese centre, as applied to thylakoids, PSII enriched membranes and oxygen evolving reaction centre preparations. In order to extend the fruitful research, collaboration will be initiated with a theoretician and another biophysicist, both from Russia, who have pioneered an electrometric technique with extreme sensitivity for the detection of very small vectorial charge shifts in biomembranes. The expected results on electrostatic constraints and techniques of their suspension will not only advance the understanding of water oxidation but likewise of other proton pumping electron transfer complexes, both natural and biomimetic. Program(-y) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Temat(-y) 42 - Physical Chemical Biology Zaproszenie do składania wniosków Data not available System finansowania Data not available Koordynator Universität Osnabrück Wkład UE Brak danych Adres Barbarastraße 11 49069 Osnabrück Niemcy Zobacz na mapie Koszt całkowity Brak danych Uczestnicy (3) Sortuj alfabetycznie Sortuj według wkładu UE Rozwiń wszystko Zwiń wszystko Centre National de la Recherche Scientifique Francja Wkład UE Brak danych Adres 75005 Paris Zobacz na mapie Koszt całkowity Brak danych Moscow State University M.V. Lomonosov Rosja Wkład UE Brak danych Adres 119899 Moscow Zobacz na mapie Koszt całkowity Brak danych Russian Academy of Sciences Rosja Wkład UE Brak danych Adres 117071 Moscow Zobacz na mapie Koszt całkowity Brak danych
