Effect of dipyridamole on the recombination kinetics between photooxidized bacteriochlorophyll and photoreduced primary quinone in reaction centres of purple bacteria.
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)-.
Knox
P P
PP
Department of Biology, Moscow State University, Russia.
Churbanova
I J
IJ
Lukashev
E P
EP
Borissevitch
G P
GP
Zakharova
N I
NI
Tabak
M
M
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
D001429:Bacteriochlorophylls; D016227:Benzoquinones; D045342:Light-Harvesting Protein Complexes; D010726:Phosphodiesterase Inhibitors; D045322:Photosynthetic Reaction Center Complex Proteins; C004532:quinone; D004176:Dipyridamole