Allakhverdiev, S. I.Karacan, M. S.Somer, G.Karacan, N.Khan, E. M.Rane, S. Y.Padhye, S.Klimov, V. V.Renger, G.2018-11-102018-11-1019940939-5075https://depositonce.tu-berlin.de/handle/11303/8486http://dx.doi.org/10.14279/depositonce-7632The capability of different manganese complexes to act as PS II electron donors in D1/D2/ cytochrome b 559 complexes has been analyzed by measuring actinic light-induced absorption changes at 680 nm (650 nm) and 340 nm, reflecting the photoaccumulation of Pheophytin- (Pheo-) and the reduction of NADP+ respectively. The data obtained reveal: a) the donor capacity of synthetic binuclear Mn(III)2 complexes containing aromatic ligands significantly exceeds that for MnCl2 in both cases, i.e. Pheo- photoaccumulation and NADP+ reduction; b) manganese complexes can serve as suitable electron donors for light-induced NADP+ reduction catalyzed by D1/D2/cytochrome b559 complexes and ferredoxin plus ferredoxin- NADP+ reductase under anaerobic conditions and c) the specific turnover rate of the system leading to NADP+ reduction is extremely small. The implications of these findings are briefly discussed.en570 Biowissenschaften; BiologiePS II reaction centermanganesepheophytin photoaccumulationNADP+ reductionArticle1865-7125