Spectroscopic resolution of the picosecond reduction kinetics of the secondary electron acceptor A1 in photosystem I.
Forward electron transfer in photosystem I from Synechocystis sp. PCC 6803 has been studied in the picosecond time range with transient absorption spectroscopy in the blue and near-UV spectral regions. From the direct measurement, at 380-390 nm, of the reduction kinetics of the phylloquinone secondary acceptor A1 and from the absence of spectral evolution between 100 ps and 2 ns, we conclude that electron transfer, from the chlorophyll a primary acceptor A0, to A1 occurs directly and completely with a time constant of about 30 ps.
Brettel
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K
Section de Bioénergétique and CNRS URA 2096, DBCM, CEA Saclay, Gif-sur-Yvette, France. brettel@dsvidf.cea.fr
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D000458:Cyanobacteria / Q000378:metabolism; D004579:Electron Transport; D007700:Kinetics; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
D045322:Photosynthetic Reaction Center Complex Proteins