TY - JOUR
T1 - Electrogenic reduction of the primary electron donor P700+ in photosystem I by redox dyes
AU - Gourovskaya, Kira N.
AU - Mamedov, Mahir D.
AU - Vassiliev, Ilya R.
AU - Golbeck, John H.
AU - Semenov, Alexey Yu
N1 - Funding Information:
Acknowledgements. The work was supported by grants from Civilian Research and Development Foundation (CRDF, Grant RB1-214), from Russian Foundation for Basic Research (Grant 97-04-50179), from the President of Russian Federation Council for Grant Proposals (Grant 96-15-97043), and from the US National Science Foundation (Grant MCB-969617a).
PY - 1997/9/8
Y1 - 1997/9/8
N2 - The kinetics of reduction of the photo-oxidized primary electron donor P700+ by redox dyes N,N,N',N'tetremethyl-p-phenylendiamine, 2,6-dichlorophenol-indophenol and phenazine methosulfate was studied in proteoliposomes containing Photosystem I complexes from cyanobacteria Synechocystis sp. PCC 6803 using direct electrometrical technique, In the presence of high concentrations of redox dyes, the fast generation of a membrane potential related to electron transfer between P700 and the terminal iron-sulfur clusters F(A)/F(B) was followed by a new electrogenic phase in the millisecond time domain, which contributes approximately 20% to the overall photoelectric response. Tills phase is ascribed to the vectorial transfer of an electron from the redox dye to the protein-embedded chlorophyll of P700+. Since the contribution of this electrogenic phase in the presence of artificial redox dyes is approximately equal to that of the phase observed earlier in the presence of cytochrome c6, it is likely that electrogenic reduction of P700+ in vivo occurs due to vectorial electron transfer within RC molecule rather than within the cytochrome c6-P700 complex.
AB - The kinetics of reduction of the photo-oxidized primary electron donor P700+ by redox dyes N,N,N',N'tetremethyl-p-phenylendiamine, 2,6-dichlorophenol-indophenol and phenazine methosulfate was studied in proteoliposomes containing Photosystem I complexes from cyanobacteria Synechocystis sp. PCC 6803 using direct electrometrical technique, In the presence of high concentrations of redox dyes, the fast generation of a membrane potential related to electron transfer between P700 and the terminal iron-sulfur clusters F(A)/F(B) was followed by a new electrogenic phase in the millisecond time domain, which contributes approximately 20% to the overall photoelectric response. Tills phase is ascribed to the vectorial transfer of an electron from the redox dye to the protein-embedded chlorophyll of P700+. Since the contribution of this electrogenic phase in the presence of artificial redox dyes is approximately equal to that of the phase observed earlier in the presence of cytochrome c6, it is likely that electrogenic reduction of P700+ in vivo occurs due to vectorial electron transfer within RC molecule rather than within the cytochrome c6-P700 complex.
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U2 - 10.1016/S0014-5793(97)00994-0
DO - 10.1016/S0014-5793(97)00994-0
M3 - Article
C2 - 9315684
AN - SCOPUS:0031559930
VL - 414
SP - 193
EP - 196
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 2
ER -