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Kinetic studies on the function of A 1 in the photosystem I reaction center
Author(s) -
Mathis P,
Sétif P
Publication year - 1988
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(88)80173-x
Subject(s) - nanosecond , photosynthetic reaction centre , photosystem i , photosystem ii , chemistry , tricine , absorption (acoustics) , phase (matter) , kinetic energy , flash photolysis , photochemistry , redox , analytical chemistry (journal) , photosynthesis , electron transfer , kinetics , materials science , reaction rate constant , biochemistry , physics , inorganic chemistry , optics , chromatography , laser , organic chemistry , quantum mechanics , composite material
Flash absorption measurements with nanosecond time resolution were conducted in the near‐ultraviolet with subchloroplast particles enriched in photosystem I, at 6°C. Around 370 nm, an absorption increase decays biphasically, with a fast phase, t= 15 ± 5 ns. Control experiments show that this rapid phase is due to the reoxidation of A 1 (presumably phylloquinone), which thus appears to function as an electron carrier in PS I at physiological temperature. The nanosecond kinetic phase is not altered if the iron‐sulfur centers F A and F B are kept reduced.