title: Stimulation of oxygen evolution in photosystem II by copper(II) ions.
abstract: We have found that copper(II) ions at about equimolar Cu2+/photosystem II (PS II) reaction center proportions stimulate oxygen evolution nearly twofold. This high affinity Cu-binding site is different from the binding sites of Mn and Ca ions. The analysis of the Cu2+ content in PS II preparations isolated from wild-type tobacco and a tobacco mutant deficient in light-harvesting complex suggests that Cu2+ may be a native component of PS II and may take part in the oxygen evolution process. At higher concentrations, Cu2+ ions inhibit oxygen evolution and quench fluorescence.
authors.affiliation: The Henryk Niewodniczañski Institute of Nuclear Physics, Kraków, Poland.
authors.forename: Kvetoslava
authors.initials: K
authors.lastname: Burda
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kruk
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Strzalka
authors.forename: Georg H
authors.initials: GH
authors.lastname: Schmid
mesh_terms: D003300:Copper / Q000494:pharmacology*; D019327:Copper Sulfate / Q000494:pharmacology; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000187:drug effects / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D014026:Nicotiana / Q000187:drug effects / Q000378:metabolism*
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D003300:Copper; D019327:Copper Sulfate; C029892:cupric chloride; D010100:Oxygen