[Electrogenic reactions in cytochrome bf-complexes in a model system].
By using the direct electrometric technique, the flash-induced generation of the difference in electrical potentials in hybrid proteoliposomes containing photosystem 1 and cytochrome bf complexes from cyanobacteria Synechocystis sp. PCC 6803 was studied. It was shown that the primary donor P700 in photosystem I and cytochrome f are predominantly localized near the outer surface of the proteoliposomal membrane, which made it possible to study for the first time electrogenic reactions of cytochrome bf complexes in a model system. In the presence of decyl plastoquinol and cytochrome c6, besides the fast electrogenic phase determined by the separation of charges in photosystem I, additional electrogenic phases in the submillisecond and millisecond ranges were observed. These phases were partially depressed in the presence of the inhibitor of the plastoquinone reductase site NQNO and fully disappeared after the addition of the inhibitor of the plastoquinol oxidase site stigmatellin. A possible mechanism of the electrogenic reactions in cytochrome bf complexes was considered.
Mamedov
M D
MD
Belozerskii Institute of Physicochemical Biology, Lomonosov Moscow State University, Vorob'evy Gory, GSP-2, Moscow, 119992 Russia.
Vitukhnovskaia
L A
LA
Zaspa
A A
AA
Semenov
A Iu
AIu
D000458:Cyanobacteria / Q000201:enzymology; D045346:Cytochrome b6f Complex / Q000737:chemistry*; D008956:Models, Chemical; D011510:Proteolipids
D011510:Proteolipids; C020485:proteoliposomes; D045346:Cytochrome b6f Complex