Inactivation of antioxidant enzymes by peroxynitrite.
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.
Grzelak
A
A
Department of Molecular Biophysics, University of Lódź, Poland. kbm@biol.uni.lodz.pl
Soszyński
M
M
Bartosz
G
G
D002374:Catalase / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000037:antagonists & inhibitors*; D006801:Humans; D009566:Nitrates / Q000494:pharmacology; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D009566:Nitrates; C039642:peroxynitric acid; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase