title: Orientation of reaction center complexes from Rhodobacter sphaeroides in proteoliposomes and the effect of o-phenanthroline on electrogenesis during primary photochemical reaction.
abstract: The orientation of Rhodobacter sphaeroides reaction center complexes (RC complexes) in proteoliposomal membranes was investigated by a direct electrometric method. Conditions were found that allow monitoring of only that RC complex fraction that is oriented with its donor side to the inner part of the proteoliposome. It is shown that o-phenanthroline, an inhibitor of electron transfer between primary (QA) and secondary (QB) quinone acceptors, can also inhibit the photoinduced QA reduction. The efficiency of this inhibition depends on the concentration of added ubiquinone. It is assumed that the laser flash-induced o-phenanthroline inhibition of primary dipole (P-870+.QA-) formation is of a competitive nature.
authors.affiliation: Peoples' Friendship University, Moscow, USSR.
authors.forename: A A
authors.initials: AA
authors.lastname: Kondrashin
authors.lastname: Semenov AYu
authors.forename: M D
authors.initials: MD
authors.lastname: Mamedov
authors.forename: L A
authors.initials: LA
authors.lastname: Drachev
authors.forename: N I
authors.initials: NI
authors.lastname: Zakharova
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism* / Q000528:radiation effects; D004579:Electron Transport / Q000187:drug effects; D008081:Liposomes; D010618:Phenanthrolines / Q000494:pharmacology; D010777:Photochemistry; D045322:Photosynthetic Reaction Center Complex Proteins; D011510:Proteolipids; D012242:Rhodobacter sphaeroides / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D001426:Bacterial Proteins; D008081:Liposomes; D010618:Phenanthrolines; D045322:Photosynthetic Reaction Center Complex Proteins; D011510:Proteolipids; C025205:1,10-phenanthroline