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Is phylloquinone an obligate electron carrier in photosystem I?
Author(s) -
Palace Gerard P.,
Franke James E.,
Warden Joseph T.
Publication year - 1987
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(87)80113-8
Subject(s) - obligate , photosystem i , chemistry , photosystem ii , biophysics , photochemistry , photosynthesis , biochemistry , botany , biology
Comparative quantitative analysis of phylloquinone content and photochemically competent P‐700 has been performed on photosystem I particles subjected to photolysis with ultraviolet irradiation. Nonirradiated control particles exhibit a phylloquinone/P‐700 stoichiometry of 1.9 ± 0.2. Photolysis of the photosystem I particles induces a progressive depletion of phylloquinone, however, photochemistry as assayed at room temperature by the photooxidation of P‐700 is unaffected. These data are not consistent with the assignment of phylloquinone as a functional intermediate at room temperature between P‐700 and the iron‐sulfur clusters, center A and center B.