Reversible conversion of nitroxyl anion to nitric oxide by superoxide dismutase - PubMed (original) (raw)

Reversible conversion of nitroxyl anion to nitric oxide by superoxide dismutase

M E Murphy et al. Proc Natl Acad Sci U S A. 1991.

Abstract

Superoxide dismutase (SOD) rapidly scavenges superoxide (O2-) and also prolongs the vasorelaxant effects of nitric oxide (NO), thought to be the endothelium-derived relaxing factor. This prolongation has been ascribed to prevention of the reaction between O2- with NO. We report that SOD supports a reversible reduction of NO to NO-. When cyanamide and catalase were used to generate NO- in the presence of SOD, NO was measured by the conversion of HbO2 to MetHb. When SOD[Cu(I)] was exposed to NO anaerobically, NO- was trapped by MetHb forming nitrosylmyoglobin. When NO was generated by 3-morpholinosydnonimine hydrochloride in the presence of SOD, NO- or a similar reductant was formed, which reduced catalase compound II and promoted the formation of the catalase [Fe(III)]-NO complex. It is, therefore, conceivable that SOD may protect NO and endothelium-derived relaxing factor by a mechanism in addition to O2- scavenging and that NO- may be a physiologically important form of endothelium-derived relaxing factor.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Biochem J. 1974 Apr;139(1):49-60 - PubMed
    1. Biochim Biophys Acta. 1958 Aug;29(2):302-7 - PubMed
    1. J Biol Chem. 1978 Dec 10;253(23):8433-43 - PubMed
    1. Clin Chem. 1980 Feb;26(2):227-31 - PubMed
    1. J Biol Chem. 1981 Sep 10;256(17):8983-6 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources