title: Disorganization of the Mn4Ca complex of photosystem II by ruthenium red: a thermoluminescence study.
abstract: Ruthenium red (RR) is known to be an inhibitor that binds to Ca2+ sites. It releases Ca2+ and Cl(-) together with the extrinsic polypeptide of 17 kDa associated with the oxygen evolving complex of photosystem II. In this work we used thermoluminescence to study S2/3QB(-) and S2QA(-) charge recombination. It is shown that RR produced a deeper inhibition of oxygen evolution compared with the effect of extrinsic polypeptide or Ca2+/Cl(-) depletion. Even though Mn is not released, the Mn cluster is disorganized by RR and the S1-->S2 transition is inhibited.
authors.affiliation: Groupe de Recherche en Biologie Végétale (GRBV), Université du Québec à Trois-Rivières, C.P. 500 Trois-Rivières, Québec, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Gauthier
authors.forename: Robert
authors.initials: R
authors.lastname: Carpentier
mesh_terms: D002118:Calcium / Q000737:chemistry*; D008163:Luminescent Measurements; D008345:Manganese / Q000737:chemistry*; D010100:Oxygen; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000187:drug effects; D012430:Ruthenium Red / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D045332:Photosystem II Protein Complex; D012430:Ruthenium Red; D008345:Manganese; D010100:Oxygen; D002118:Calcium