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The Nijmegen Hemostasis Assay: Simultaneous Fluorogenic Measurement of Thrombin and Plasmin Generation in a Single Well
Published on: February 27, 2026
Peroxynitrite and fibrinolytic system: the effect of peroxynitrite on plasmin activity
Pawel Nowak1, Joanna Kołodziejczyk, Barbara Wachowicz
1Department of General Biochemistry, University of Lodz, Poland. pnowak@biol.uni.lodz.pl
Abstract:
We have shown that peroxynitrite (ONOO-) inhibits streptokinase-induced conversion of plasminogen to plasmin in a concentration-dependent manner and reduces both amidolytic (IC5o approximately 280 microM at 10 microM concentration of enzyme) and proteolytic activity of plasmin. Spectrophotometric and immunoblot analysis of peroxynitrite-treated plasminogen demonstrates a concentration-dependent increase in its nitrotyrosine residues that correlates with a decreased generation of active plasmin. Peroxynitrite (1 mM) causes the nitration of 2.9 tyrosines per plasminogen molecule. Glutathione, like deferoxamine, partially protects plasminogen from peroxynitrite-induced inactivation and reduces the extent of tyrosine nitration. These data suggest that nitration of plasminogen tyrosine residues by peroxynitrite might play an important role in the inhibition of plasmin catalytic activity.
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