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Chance 1961 J Biol Chem-I

From Bioblast
Publications in the MiPMap
Chance B, Hollunger G (1961) The interaction of energy and electron transfer reactions in mitochondria I. General properties and nature of the products of succinate-linked reduction of pyridine nucleotide. J Biol Chem 236:1534-43.

ยป PMID: 13692277 Open Access

Chance B, Hollunger G (1961) J Biol Chem

Abstract: A thermodynamically improbable reduction of pyridine nucleotide caused by the addition of succinate to isolated mitochondria has been demonstrated. The material so reduced exhibits kinetic responses, some of which can suggest its consideration as a member of the respiratory chain, but a quantitative examination of the kinetics of oxidation and reduction shows that only a small portion of the total respiratory activity in succinate oxidation passes through the diphosphopyridine nucleotide-linked pathway.

The nature of the reduction product has been examined in heart, liver, and guinea pig kidney mitochondria and is found to be material absorbing at 340 mยต and having a fluorescence emission maximum at 440 mยต. Direct chemical assays on kidney mitochondria indicate that the reduced material is diphosphopyridine nucleotide. A preliminary evaluation of various hypotheses to explain this result leads us tentatively to reject hypotheses based upon a single pool of mitochondrial pyridine nucleotide in which diphosphopyridine nucleotide and succinate compete for oxidizing equivalents from the cytochrome chain.

Further indication of the complexities of this reaction is that respiration can be initiated by succinate without measurable pyridine nucleotide reduction and that a transition from aerobiosis in state 3 to anaerobiosis (state 5) can lead to a higher oxidation level of pyridine nucleotide than was observed aerobically in state 4. These observations suggest that the presence of adenosine 5โ€™-diphosphate inhibits pyridine nucleotide reduction under both aerobic and anaerobic conditions and support the possibility that an energy-linked reaction may be involved. โ€ข Keywords: Energy transfer, Eletcron transfer, Succinate, Pyridine nucleotide, ADP


Labels: MiParea: Respiration 


Organism: Guinea pig  Tissue;cell: Heart, Liver, Kidney  Preparation: Isolated mitochondria 

Regulation: ADP  Coupling state: OXPHOS  Pathway:


Made history