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Tuena 1969 Eur J Biochem

From Bioblast
Publications in the MiPMap
Tuena M, Gómez-Puyou A, Peña A, Chávez E, Sandoval F (1969) Effect of ATP on the oxidation of succinate in rat brain mitochondria. Eur J Biochem 11:283-90.

» PMID: 5360409

Tuena M, Gomez-Puyou A, Pena A, Chavez E, Sandoval F (1969) Eur J Biochem

Abstract: The effect of ATP on the aerobic oxidation of succinate and on the succinic dehydrogenase activity of isolated rat brain mitochondria has been studied.

1. The addition of dinitrophenol to brain mitochondria with succinate as substrate produced a small activating effect of oxygen uptake which was followed by inhibition of respiration; the further addition of ATP produced a high rate of respiration.

2. This effect of ATP was enhanced by added Mg++ and oligomycin and was diminished, but not abolished, by inorganic phosphate.

3. Experiments were conducted which indirectly indicated that oxaloacetate may be involved in the inhibition of the aerobic oxidation of succinate in fresh brain mitochondria incubated with dinitrophenol; however, attempts to find out if ATP removed oxaloacetate through a particular ATP requiring metabolic pathway were unsuccessful.

4. In aged, sonicated, and frozen and thawed brain mitochondria incubated with dinitrophenol, ATP still activated the aerobic oxidation of succinate.

5. The assay of succinic dehydrogenase (EC in aged brain mitochondria revealed that ATP diminished the Km for succinate and increased the Vmax of succinic dehydrogenase. ATP also produced a shift in the pH optimum of succinic dehydrogenase and a partial protection of the enzyme against heat denaturation.

Labels: MiParea: Respiration 

Organism: Rat  Tissue;cell: Nervous system  Preparation: Isolated mitochondria  Enzyme: Complex II;succinate dehydrogenase  Regulation: ATP, pH, Substrate  Coupling state: ET  Pathway:

Succinate, ATP, Oxaloacetate, Oligomycin