Studies On The Photoassembly Of Water-oxidizing Complex Of Photosystem II

In this thesis, the process of photoassembly of the water-oxidizing complex of photosystem II membranes has been examined in different bioinorganic chemistry conditions. The results obtained here were summarized as follows:1. Two groups of dinuclear manganese complexes, in which manganese atoms in one group contain same ligands and valence state but different linkage mode while manganese atoms in another group have same linkage mode and valence state but different ligands, were used to reconstitute the water-oxidizing complex (WOC) in Mn-depleted PSII preparation. It was shown that difference in the properties of ligand or linkage mode of Mn atom within dinuclear manganese complexes can affect efficiencies of complexes in the reconstituting the electron transfer and oxygen-evolving capacities. But, the effect of ligand and linkage mode on the efficiency of reconstitution of WOC is smaller than that of redox states of Mn atom. It is suggested from our results that redox states of Mn atom is one of the most important factors affecting the reconstitution of WOC.2. Efficiency of three tetranuclear manganese complexes in reconstituting electron transport and O2 evolution activity in Mn-depleted Photosystem II preparations is analyzed. Two Mn-complexes which have fewer ligands and small size participate in a more effective reactivation of oxygen evolution than the other Mn-complex. It is inferred from our results that recovery of electron transport and O2 evolution activity with polynuclear Mn-complexes is affected with the ligand number and size. Moreover, these above-mentioned Mn-complexes are more sensitive to the addition of CaCl2, because there are more carboxyl interacting with Ca2+ during photoactivation in these Mn-complexes, which is suggested to support the ligation of Mn atom and formation of active WOC.3. A manganese complex that contains Ca were synthesized and used to...