Inactivation of antioxidant enzymes by peroxynitrite

Scand J Clin Lab Invest. 2000 Jul;60(4):253-8. doi: 10.1080/003655100750046413.


Exposure of hemolysates and whole erythrocytes to peroxynitrite (bolus of 50 micromol dm(-3)-2 mmol dm(-3)) was found to inactivate erythrocyte antioxidant enzymes: glutathione peroxidase > superoxide dismutase > catalase. Inactivation of antioxidant enzymes by peroxynitrite may be one reason for the secondary oxidative stress in peroxynitrite-treated cells. When hemoglobin was not converted into the cyanmet form, an apparent activation of glutathione peroxidase activity by peroxynitrite was observed in hemolysates; this effect was artifactual and due to the pseudoenzymatic glutathione peroxidase activity of hemoglobin.

MeSH terms

  • Catalase / antagonists & inhibitors*
  • Enzyme Inhibitors / pharmacology*
  • Glutathione Peroxidase / antagonists & inhibitors*
  • Humans
  • Nitrates / pharmacology
  • Oxidative Stress
  • Superoxide Dismutase / antagonists & inhibitors*


  • Enzyme Inhibitors
  • Nitrates
  • peroxynitric acid
  • Catalase
  • Glutathione Peroxidase
  • Superoxide Dismutase