title: Inhibition of oxygen evolution in Photosystem II by Cu(II) ions is associated with oxidation of cytochrome b559.
abstract: We have found that elevated copper concentrations, apart from the inhibition of oxygen evolution, changed the initial states distribution of the oxygen-evolving complex. Already at low concentrations, copper ions oxidized the low-potential form of cytochrome b (559) and also its high-potential form at higher concentrations at which fluorescence quenching was observed. We suggest that the primary target sites in Photosystem II for copper is tyrosine(z), both cytochrome b (559) forms and chlorophyll(z), and that these sites are the source of the copper-induced fluorescence quenching and oxygen evolution inhibition in Photosystem II.
authors.affiliation: The Henryk Niewodniczanski Institute of Nuclear Physics, ul. Radzikowskiego 152, 32-342 Kraków, Poland.
authors.forename: Kvetoslava
authors.initials: K
authors.lastname: Burda
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kruk
authors.forename: Georg H
authors.initials: GH
authors.lastname: Schmid
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Strzalka
mesh_terms: D003300:Copper / Q000494:pharmacology; D003573:Cytochrome b Group / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D045342:Light-Harvesting Protein Complexes; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000187:drug effects / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D014026:Nicotiana / Q000378:metabolism*
chemical_list: D003573:Cytochrome b Group; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D003300:Copper; C019313:cytochrome b559; C029892:cupric chloride; D010100:Oxygen