Abstract
Various sites of ferricyanide reduction were studied in spinach chloroplasts. It was found that in the presence of dibromothymoquinone a fraction of ferricyanide reduction was dibromothymoquinone sensitive, implying that ferricyanide can be reduced by photosystem I as well as photosystem II. To separate ferricyanide reduction sites in photosystem II, orthophenanthroline and dichlorophenyl dimethylurea inhibitions were compared at various pH's. It was noted that at low pH ferricyanide reduction was not completely inhibited by orthophenanthroline. At high pH's, however, inhibition of ferricyanide reduction by orthophenanthroline was complete. It was found that varying concentration of orthophenanthroline at a constant pH showed different degrees of inhibition. In the study of ferricyanide reduction by photosystem II various treatments affecting plastocyanin were performed. It was found that Tween-20 or KCN treatments which inactivated plastocyanin did not completely inactivate ferricyanide reduction. These data support the conclusion that ferricyanide accepts electrons both before and after plastoquinone in photosystem II.
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Abbreviations
- DCMU:
-
3-(3,4-dichlorophenyl)-1,1-dimethyurea
- MV:
-
methyl viologen
- DBMIB:
-
2,5-dibromothymoquinone
- DMBQ:
-
2,6-dimethyl benzoquinone
- OP:
-
1,10-orthophenanthroline
- TMPD:
-
tetramethyl-p-phenylenediamine
- PS 1:
-
photosystem I
- PS II:
-
photosystem II
- SN:
-
sucrose-sodium chloride chloroplasts
References
A. Trebst, E. Harth, and W. Draber,Z. Naturforsch.,25B (1970) 1157.
P. Horton and W.A. Cramer,Biochim. Biophys. Acta,368 (1974) 348.
D.R. Ort and S. Izawa,Plant Physiol.,52 (1973) 595.
A.T. Jagendorf and M. Avron,J. Biol Chem.,231 (1958) 277.
J. Brand, T. Baszynski, F.L. Crane, and D.W. Krogmann,J. Biol Chem.,247 (1972) 2814.
R. Barr, D. Rosen, and F.L. Crane,Proc. Indiana Acad. Sci.,84 (1975) 147.
S. Izawa, R. Kraayenhof, E.K. Ruuge, and D. Devault,Biochim. Biophys. Acta,314 (1973) 328.
A. Trebst, in:Methods in Enzymology, Vol. XXIV part B, Academic Press, New York (1972) 146–165.
M. Nishimura,Brookhaven Symp. Biol.,19 (1966) 132.
W. Oettmeier and R. Grewe,Z. Naturforsch.,29c (1974) 545.
R. Barr and F.L. Crane,Biochem. Biophys. Res. Commun.,60 (1974), 748.
M. Avron, in:Bioenergetics of Photosynthesis, Academic Press, New York (1975) pp. 373–386.
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Supported by NSF Grant BMS 74-19689.
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Banaszak, J., Barr, R. & Crane, F.L. Evidence for multiple sites of ferricyanide reduction in chloroplasts. J Bioenerg Biomembr 8, 83–92 (1976). https://doi.org/10.1007/BF01558630
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DOI: https://doi.org/10.1007/BF01558630