A novel phenomenon of burst of oxygen uptake during decavanadate-dependent oxidation of NADH

Kalyani, P and Ramasarma, T (1993) A novel phenomenon of burst of oxygen uptake during decavanadate-dependent oxidation of NADH. In: Molecular and Cellular Biochemistry, 121 (1). pp. 21-29.

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Abstract

Oxidation of NADH by decavanadate, a polymeric form vanadate with a cage-like structure, in presence of rat liver microsomes followed a biphasic pattern. An initial slow phase involved a small rate of oxygen uptake and reduction of 3 of the 10 vanadium atoms. This was followed by a second rapid phase in which the rates of NADH oxidation and oxygen uptake increased several-fold with a stoichiometry of NADH: O2 of 1ratio1. The burst of NADH oxidation and oxygen uptake which occurs in phosphate, but not in Tris buffer, was prevented by SOD, catalase, histidine, EDTA, MnCl2 and CuSO4, but not by the hydroxyl radical quenchers, ethanol, methanol, formate and mannitol. The burst reaction is of a novel type that requires the polymeric structure of decavanadate for reduction of vanadium which, in presence of traces of H2O2, provides a reactive intermediate that promotes transfer of electrons from NADH to oxygen.

Item Type:	Journal Article
Publication:	Molecular and Cellular Biochemistry
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Keywords:	decavanadate;NADH oxidation;oxygen burst;microsomes.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	31 Jan 2011 05:10
Last Modified:	31 Jan 2011 05:10
URI:	http://eprints.iisc.ac.in/id/eprint/35301

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