title: Thermodynamic properties of the reaction center of Rhodopseudomonas viridis. In vivo measurement of the reaction center bacteriochlorophyll-primary acceptor intermediary electron carrier.
abstract: The thermodynamic properties of redox components associated with the reaction center of Rhodopseudomonas viridis have been characterized with respect to their midpoint potentials and relationship with protons. In particular a midpoint potential for the intermediary electron carrier acting between the reaction center bacteriochlorophyll and the primary acceptor has been determined. The rationale for this measurement was that the light-induced triplet/biradical EPR signal would not be observed if this intermediate was chemically reduced before activation. The midpoint potential of the intermediary at pH 10.8 is about --400 mV (n=1).
mesh_terms: D001429:Bacteriochlorophylls / Q000378:metabolism*; D002734:Chlorophyll / Q000031:analogs & derivatives*; D003580:Cytochromes / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D004735:Energy Transfer; D007700:Kinetics; D008027:Light; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010788:Photosynthesis; D012241:Rhodopseudomonas / Q000648:ultrastructure; D012247:Rhodospirillum rubrum / Q000378:metabolism*; D013045:Species Specificity; D013816:Thermodynamics
chemical_list: D001429:Bacteriochlorophylls; D003580:Cytochromes; D002734:Chlorophyll