UV‐spectral characterization in Tris‐washed chloroplasts of the redox component D1which functionally connects the reaction center with the water‐oxidizing enzyme system Y in photosynthesis
- 24 April 1984
- journal article
- Published by Wiley in FEBS Letters
- Vol. 169 (2) , 219-223
- https://doi.org/10.1016/0014-5793(84)80322-1
Abstract
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, Dox1, becomes mainly reduced by the primary (Q−A) and secondary (Q−B) plastoquinone in non‐B‐type and B‐type system II centers, respectively. Dox1reduction with Q−Aoccurs witht1/= 60–100 ms, and Dox1reduction with Q−Bis biphasic with half‐times of 0.1–0.5 and 5–10 s. The difference spectrum of the oxidizedvsreduced form of D1is 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.Keywords
This publication has 21 references indexed in Scilit:
- A Tris-induced change in the midpoint potential of Z, the donor to photosystem II, as determined by the kinetics of the back reactionFEBS Letters, 1983
- Kinetics of the oxidation—reduction reactions of the photosystem II quinone acceptor complex, and the pathway for deactivationFEBS Letters, 1983
- Spectral characterization in the ultraviolet region of the precursor of photosynthetically evolved oxygen in isolated trypsinized chloroplastsBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1983
- Studies on the proton release pattern of the donor side of system IIFEBS Letters, 1982
- Spectral and kinetic pH‐dependence of fast and slow signal II in tris‐washed chloroplastsFEBS Letters, 1982
- The effect of pH on the reduction kinetics of P-680 in tris-treated chloroplastsBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1980
- Flash induced fluorescence kinetics in chloroplasts in the 20 μs-100 s time range in the presence of 3(3,4-dichlorophenyl)-1,1-dimethylurea. Effects of hydroxylamineBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1977
- Reaction kinetics for positive charge accumulation on the water side of choloplast photosystem IIFEBS Letters, 1976
- Rapid fluorescence changes observed in chloroplasts: Their relationship to the O2 evolving systemBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1973
- The stoichiometry of photophosphorylationBiochemical and Biophysical Research Communications, 1965