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'Cyclic Phosphorylation' in keywords
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1978 (1)
1972 (1)
1Author    R. G. Binder, B. R. SelmanRequires cookie*
 Title    Ferredoxin Catalyzed Cyclic Photophosphorylation: Reversal of Dibromothymoquinone Inhibition by N ,N ,N ',N '-T etram ethyl- /j-phenylenediamine  
 Abstract    Conditions for washed, spinach thylakoid membranes to catalyze cyclic phosphorylation using ferredoxin as the cofactor for electron transfer have been re-examined. It was found necessary to ''redox poise" the system; however, the best method to accomplish the poising seemed to be the use of a reductant (glucose-6-phosphate) and not by optimizing the rate of phosphorylation with 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). Under these conditions, ferredoxin catalyzed cyclic phosphorylation was found to be sensitive to the inhibitors antimycin A and dibromothymo­ quinone (DBM IB). The inhibition of ferredoxin catalyzed cyclic phosphorylation by DBMIB, but not by antimycin A, was completely reversed by N, N, N', N'-tetramethyl-p-phenylenediamine (TM PD). These data are taken as further support for the function of plastoquinone in ferredoxin catalyzed cyclic phosphorylation. The effect of TMPD in reversing the DBMIB inhibition is inter­ preted as the formation of a TMPD bypass on the internal side of the thylakoid membrane around the DBMIB site of inhibition. 
  Reference    Z. Naturforsch. 33c, 261—265 (1978); received November 22 1977 
  Published    1978 
  Keywords    Cyclic Phosphorylation, Chloroplasts, Ferredoxin, Dibromothymoquinone, Phenylenediamine, Photosynthesis 
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 TEI-XML for    default:Reihe_C/33/ZNC-1978-33c-0261.pdf 
 Identifier    ZNC-1978-33c-0261 
 Volume    33 
2Author    G. A. Hauska, P. V. SaneRequires cookie*
 Title    II. Latent ATPase, Proton Pump, Cyclic Phosphorylation and its Sensitivity towards Ammonia  
 Abstract    Cyclic phosphorylation and latent ATPase follow the distribution of photosystem I in the chloro-plast membrane. Both activities are found higher in stroma lamellae than in grana. The extent of proton uptake is found to be higher in the grana. Since this uptake depends on internal volume and buffer capacity besides proton pump activity, the distribution of the proton pump proper remains to be elucidated. Any fragmentation of the large inner compartment of the chlorolast lamellar system into smaller vesicles results in decreased sensitivity of cyclic phosphorylation to uncoupling by ammonium chloride. Consequently both, isolated grana and stroma lamellae, show decreased uncoupling by ammonium chloride. The effect can be explained by the action of a membrane potential in photo-phosphorylation which builds up during illumination and might be more stable in a system with the larger number of individual compartments just for statistical reasons. No assumption on changes in specific ion permeabilities during fragmentation of chloroplasts are needed. 
  Reference    (Z. Naturforsch. 27b, 938—942 [1972]; leeeived May 15 1972) 
  Published    1972 
  Keywords    Chloroplast fragmentation, ATPase, Proton pump, Cyclic Phosphorylation, NH4Cl-uncoupling 
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 TEI-XML for    default:Reihe_B/27/ZNB-1972-27b-0938.pdf 
 Identifier    ZNB-1972-27b-0938 
 Volume    27