Synergism of ammonium and palmitic acid in uncoupling of electron transfer and ATP synthesis in chloroplasts
| Autor: | L. A. Vasyukhina, V. K. Opanasenko |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Chloroplasts
Protonophore Inorganic chemistry Palmitic Acid Photosystem I Photosynthesis Biochemistry Ammonium Chloride Electron Transport Palmitic acid Inhibitory Concentration 50 chemistry.chemical_compound Electron transfer Adenosine Triphosphate Ammonium Plant Proteins Ionophores Photosystem I Protein Complex ATP synthase biology Uncoupling Agents Peas General Medicine Hydrogen-Ion Concentration Plant Leaves Chloroplast Kinetics chemistry biology.protein Biophysics |
| Zdroj: | Biochemistry (Moscow). 74:643-647 |
| ISSN: | 1608-3040 0006-2979 |
| DOI: | 10.1134/s000629790906008x |
| Popis: | Uncoupling by ammonium of electron transfer and ATP synthesis during linear transfer of electrons from water to photosystem 1 acceptors was studied in pea chloroplasts. It was shown that 40 microM palmitic acid decreased several-fold the ammonium concentrations necessary for 50% inhibition of ATP synthesis. The protonophore carbonyl cyanide m-chlorophenylhydrazone has no such property. The enhancement by palmitate of ammonium-induced uncoupling is accompanied by acceleration of basal electron transfer and decrease in the photoinduced uptake of hydrogen ions (H+). In the absence of ammonium, palmitate has no effect on basal transport and stimulates uptake of hydrogen ions. This means that in the case of combined action of palmitate and ammonium an additional leakage of H+ takes place, resulting in dissipation of the pH gradient. Synergic action of two metabolites, free fatty acid and ammonium, is supposed to provide for functioning of a system of mild regulation of energy coupling processes in native plant cell chloroplasts. Possible mechanisms of synergism are discussed. |
| Databáze: | OpenAIRE |
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