Objective Research objectives and content Advanced Electron Paramagnetic Resonance (EPR) techniques will be employed in order to gain new insights in the water-oxidation chemistry of the 02-evolving complex (OEC) of Photosystem II (PSII) by using nitric oxide (NO) as a spin probe and redox agent. The novel EPR signals associated with the interaction of NO with the S1-State of the OEC as well as the tyrosine D (YD) NO iminoxyl radical will be studied in detail using EPR in combination with theoretical simulations. The interaction of the redox active tyrosine Z (Yz) with NO will be explored in detail. The different modes of NO binding to the S, and S2 redox states of the OEC will be probed via C1 INO and NO/NH3 competition experiments. The redox chemistry of NO with the S,/S2-states will be studied systematically in order to stabilize new spin states of the OEC and thus obtain valuable new information on the structure, nuclearity and magnetic properties of the Mn-cluster responsible for the water-oxidation chemistry. Training content (objective, benefit and expected impact) The applicant will expand his training in biological magnetic resonance via the use of high-field EPR, FT-EPR and ENDOR techniques in order to study the functional photochemistry of the OEC in PSII. New valuable insights are expected to be obtained on the properties and reaction mechanism of nature's unique water-oxidizing catalyst. Links with industry / industrial relevance (22) Fields of science natural scienceschemical sciencesphysical chemistryphotochemistrynatural scienceschemical sciencescatalysis Programme(s) FP4-TMR - Specific research and technological development programme in the field of the training and mobility of researchers, 1994-1998 Topic(s) 0303 - Return grants TC03 - Biological, Medicinal and Pharmaceutical Chemistry Call for proposal Data not available Funding Scheme RGI - Research grants (individual fellowships) Coordinator National Centre for Scientific Research 'Demokritos' EU contribution No data Address Aghia Paraskevi 15310 Athens Greece See on map Total cost No data