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Electrogenesis associated with proton transfer in the reaction center protein of the purple bacterium Rhodobacter sphaeroides
Author(s) -
Drachev L.A.,
Mamedov M.D.,
Mulkidjanian A.Ya.,
Semenov A.Yu.,
Shinkarev V.P.,
Verkhovsky M.I.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80038-k
Subject(s) - rhodobacter sphaeroides , photosynthetic reaction centre , chemistry , bacteriochlorophyll , photochemistry , quinone , electron acceptor , acceptor , dimer , electron transfer , proton , purple bacteria , moiety , ubiquinol , rhodospirillaceae , electron donor , stereochemistry , pigment , photosynthesis , coenzyme q – cytochrome c reductase , biochemistry , cytochrome c , organic chemistry , catalysis , physics , quantum mechanics , mitochondrion , condensed matter physics
Electrogenic events in the photosynthetic reaction center complex (RC), accompanying single‐ and two‐electron reduction of the secondar quinone acceptor Q b , were investigated. In the presence of inhibitors of electron transfer via the bc 1 ‐complex, the kinetics of formation of the transmembrane electric potential difference induced by two successive light flashes exhibit a few phases. Besides the fast phase A which is due to the charge separation between the bacteriochlorophyll dimer P and primary quinone acceptor q a , two slower atrazine‐sensitive phases, BI and BII, were observed. Phase BI is suggested to be due to proton transfer between the amino acid residues of the reaction center protein, and phase BII due to proton uptake during the second flash‐induced formation of ubiquinol. A possible model of electrogenesis in the acceptor moiety of the RC is discussed.