title: Effect of dipyridamole on the recombination kinetics between photooxidized bacteriochlorophyll and photoreduced primary quinone in reaction centres of purple bacteria.
abstract: The action of dipyridamole (DIP) on dark recombination between the photooxidized special pair bacteriochlorophyll BChl2+ and reduced primary quinone acceptor Q(A)- in the reaction centres (RCs) of the bacteria Rhodobacter sphaeroides was studied in the presence of different detergents (LDAO, Triton X-100, sodium cholate, sodium dodecyl sulfate). DIP accelerated this reaction approximately 4-5-fold. In RCs with the extracted H-subunit, the effect of DIP was observed at lower concentrations. The possibility of modification of the RC structure-dynamic state by DIP (including changes in RC hydrogen bonds) is proposed. The modification obviously disturbs the processes of the long-life electrostatic stabilization of Q(A)-.
authors.affiliation: Department of Biology, Moscow State University, Russia.
authors.forename: P P
authors.initials: PP
authors.lastname: Knox
authors.forename: I J
authors.initials: IJ
authors.lastname: Churbanova
authors.forename: E P
authors.initials: EP
authors.lastname: Lukashev
authors.forename: G P
authors.initials: GP
authors.lastname: Borissevitch
authors.forename: N I
authors.initials: NI
authors.lastname: Zakharova
authors.forename: M
authors.initials: M
authors.lastname: Tabak
mesh_terms: D001429:Bacteriochlorophylls / Q000378:metabolism*; D016227:Benzoquinones / Q000378:metabolism*; D004176:Dipyridamole / Q000378:metabolism*; D007700:Kinetics; D045342:Light-Harvesting Protein Complexes; D010084:Oxidation-Reduction; D010726:Phosphodiesterase Inhibitors / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D012242:Rhodobacter sphaeroides / Q000378:metabolism
chemical_list: D001429:Bacteriochlorophylls; D016227:Benzoquinones; D045342:Light-Harvesting Protein Complexes; D010726:Phosphodiesterase Inhibitors; D045322:Photosynthetic Reaction Center Complex Proteins; C004532:quinone; D004176:Dipyridamole