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Lardy 1953 J Biol Chem

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Lardy HA, Wellman H (1953) The catalytic effect of 2,4-dinitrophenol on adenosinetriphosphate hydrolysis by cell particles and soluble enzymes. J Biol Chem 201:357-70.

Β» PMID: 13044805 Open Access

Lardy HA, Wellman H (1953) J Biol Chem

Abstract: 2,4-Dinitrophenol greatly enhanced the liberation of inorganic phosphate from ATP by the nuclear and mitochondrial fraction of rat liver. The microsomal and supernatant fractions did not exhibit this effect.

With mitochondria (Mw) the rate of phosphate liberation was proportional to the DNP concentration up to 6 X 10-5 M In the presence of excess DNP the rate was proportional to the quantity of Mw nd to time.

With both fresh and preaged Mw, the response to DNP was much greater in mediums containing salt (either NaCl or KCl) than in isotonic sucrose. Magnesium salts in appreciable concentrations depressed the response of fresh Mw to DNP, but enhanced the response in preaged Mw. Calcium salts, which activate ATP hydrolysis by fresh Mw in the absence of DNP, also depressed the effect of DNP on phosphate liberation. Magnesium salts enhanced phosphate liberation by preaged Mw both in the presence and absence of DNP. Calcium was virtually without effect in preaged Mw.

Oxalacetate enhanced phosphate liberation from ATP by fresh Mw. This dicarboxylic acid as well as succinate and L-malate depressed the effect of DNP on phosphate liberation. Fatty acids also depressed the effect of DNP. Caprylate enhanced phosphate liberation, probably be- cause of its surface activity.

The thiol inhibitor, p-chloromercuribenzoate, strongly depressed the effect of DNP; iodoacetate and o-iodosobenzoate did not.

Continued in Free Text β€’ Keywords: ATP hydrolysis, 2, 4-dinitrophenol, p-chloromercuribenzoate


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Organism: Rat  Tissue;cell: Liver  Preparation: Isolated mitochondria 

Regulation: ADP, ATP  Coupling state: OXPHOS 


Made history 

  • Abstract Continued

Water extracts of acetone-desiccated Mw contain an Mg++-activated enzyme which hydrolyzes ATP. The activity was enhanced about 100 per cent by DNP. Extracts from preaged Mw contain less of this enzyme than do extracts from fresh Mw.

DNP is more effective in enhancing respiration of Mw in the presence of added ATP than in its absence. A possible explanation for this effect is discussed.