The O2 uptake linked to NADH2 and succinate oxidation was observed in chromatophores from photosynthetically grown Chromatium vinosum.The maximal rate was 60-120 nmoles of O2 uptake per min per ̈mole of bacterio-chlorophyll. The rate of O2 uptake linked to NADH2 oxidation was higher in the neutral-to-acidic pH range than in the alkaline range, whereas that linked to succinate oxidation was higher in the alkaline range.The O2 uptake linked to NADH2 oxidation was inhibited by rotenone, amytal, antimycin A, KCN and NaN3, while that linked to succinate oxidation was inhibited by antimycin A, KCN and NaN3. Malate, citrate, pyruvate, acetate, α-ketoglutarate, NADPH2 and thiosulfate did not serve as substrates for the O2 uptake of isolated chromatophores.The rates of the O2 uptake linked to both NADH2 and succinate oxidation were not stimulated by adding uncouplers or under phosphorylating conditions. Little or no ATP was synthesized in the dark, coupled to either NADH2 or succinate oxidation, in spite of a high activity of photophosphorylation in Chromatium chromatophores.
|Number of pages||7|
|Journal||Plant and Cell Physiology|
|Publication status||Published - May 1 1980|
All Science Journal Classification (ASJC) codes
- Plant Science
- Cell Biology