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UV‐spectral characterization in Tris‐washed chloroplasts of the redox component D 1 which functionally connects the reaction center with the water‐oxidizing enzyme system Y in photosynthesis
Author(s) -
Weiss W.,
Renger G.
Publication year - 1984
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(84)80322-1
Subject(s) - plastoquinone , chemistry , redox , p680 , photosynthetic reaction centre , tris , oxidizing agent , photochemistry , analytical chemistry (journal) , photosynthesis , absorption (acoustics) , kinetics , chloroplast , photosystem ii , inorganic chemistry , materials science , electron transfer , thylakoid , biochemistry , chromatography , physics , photosystem i , organic chemistry , quantum mechanics , composite material , gene
Amplitude and relaxation kinetics of UV‐absorption changes induced in Tris‐washed chloroplasts by the second flash of repetitive double flash groups were found to be dependent on the time between the flashes of each group. An analysis of these data leads to the conclusion that after oxidation by P680 + the donor component, D ox 1 , becomes mainly reduced by the primary (Q − A ) and secondary (Q − B ) plastoquinone in non‐B‐type and B‐type system II centers, respectively. D ox 1 reduction with Q − A occurs with t 1/ = 60–100 ms, and D ox 1 reduction with Q − B is biphasic with half‐times of 0.1–0.5 and 5–10 s. The difference spectrum of the oxidized vs reduced form of D 1 is presented in the range 250–370 nm. It is characterized by positive bands peaking at 265–270 and 300–305 nm with a smaller band around 350 nm; negative bands are not observed.