Reversible conversion of nitroxyl anion to nitric oxide by superoxide dismutase.
AUTOR(ES)
Murphy, M E
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=53031Documentos Relacionados
- Formation of free nitric oxide from l-arginine by nitric oxide synthase: direct enhancement of generation by superoxide dismutase.
- Nitroxyl anion – the universal signalling partner of endogenously produced nitric oxide?
- Regulation of the vascular extracellular superoxide dismutase by nitric oxide and exercise training
- Nucleotide sequence of Coxiella burnetii superoxide dismutase.
- Free radicals and inflammation. Protection of phagocytosine leukocytes by superoxide dismutase.