title: [Effect of dipyridamole on recombination of photooxidized bacteriochlorophylla and photoreduced primary quinone in reactive centers of purple bacteria and degradation of form M412 of bacteriorhodopsin].
abstract: It is shown that the addition of dipyridamole (2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4d]py rim idine) (up to 10(-4) M) leads to a drastic acceleration of the dark recombination reaction between photooxidized bacteriochlorophyll and photoreduced primary quinone in reaction centers of Rhodobacter sphaeroides. The value of the acceleration is similar to that registered under cryogenic temperatures. The extent of the effect of dipyridamole derivatives depended on their structure. In wild-type bacteriorhodopsin and D96N mutant, dipyridamole slowed down the Schiff base reprotonation (the kinetics of M412 form decay was registered). It is suggested that dipyridamole can influence the structural and dynamic state of membrane proteins by affecting the system of their hydrogen-bonds and thus modify electron and proton transport processes.
authors.affiliation: Biological Department, Lomonosov Moscow State University, Russia.
authors.forename: N L
authors.initials: NL
authors.lastname: Zakharov
authors.forename: E P
authors.initials: EP
authors.lastname: Lukashev
authors.forename: P P
authors.initials: PP
authors.lastname: Noks
authors.forename: N Kh
authors.initials: NKh
authors.lastname: Seĭfullina
authors.forename: I Iu
authors.initials: IIu
authors.lastname: Churbanova
mesh_terms: D001429:Bacteriochlorophylls / Q000378:metabolism*; D001436:Bacteriorhodopsins / Q000378:metabolism*; D004176:Dipyridamole / Q000494:pharmacology*; D006860:Hydrogen Bonding; D010084:Oxidation-Reduction; D010777:Photochemistry; D012242:Rhodobacter sphaeroides / Q000187:drug effects* / Q000378:metabolism
chemical_list: D001429:Bacteriochlorophylls; D001436:Bacteriorhodopsins; D004176:Dipyridamole