title: Peroxynitrite and fibrinolytic system-The effects of peroxynitrite on t-PA-induced plasmin activity.
abstract: The aim of the present study was the investigation of peroxynitrite (ONOO(-)) effects on fibrinolysis in vitro and in silico. The exposure of human plasminogen to ONOO(-) (10-1000μM) resulted in a decrease of t-PA-induced amidolytic activity of plasmin; the inhibitory effect was associated with the increasing level of 3-nitrotyrosine in plasminogen/plasmin molecule. Furthermore, ONOO(-) displayed both the ability to impair the t-PA-induced activation of plasminogen to plasmin, and to reduce the rate of fibrin lysis by plasmin. The susceptibility of plasminogen in blood plasma to nitrative action of ONOO(-) was revealed by the immunoprecipitation technique. To confirm the hypothesis that 3-nitrotyrosine generation is crucial for the impairment of plasmin activity, (-)-epicatechin, a polyphenolic antioxidant that selectively prevents tyrosine nitration, was used both for in vitro experiments as well as for in silico studies on ONOO(-), ONOOH and (-)-epicatechin binding and plasminogen nitration. (-)-Epicatechin effectively protected plasminogen against ONOO(-)-induced inactivation and significantly reduced the level of 3-nitrotyrosine. The obtained results revealed tyrosine nitration as the most likely mechanism of the inhibitory effect of ONOO(-) on plasmin(ogen) functions. The possible role of tyrosine modifications was additionally confirmed by bioinformatics calculations with indication of nitration susceptible tyrosine residues.
authors.affiliation: Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland. Electronic address: joannak@biol.uni.lodz.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kolodziejczyk-Czepas
authors.affiliation: Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Michal Blazej
authors.initials: MB
authors.lastname: Ponczek
authors.affiliation: Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Nowak
mesh_terms: D000595:Amino Acid Sequence; D004789:Enzyme Activation / Q000187:drug effects; D005341:Fibrinolysin / Q000378:metabolism*; D005342:Fibrinolysis / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects; D030421:Peroxynitrous Acid / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010958:Plasminogen / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D016415:Sequence Alignment; D010959:Tissue Plasminogen Activator / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives
chemical_list: D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine; D010958:Plasminogen; D010959:Tissue Plasminogen Activator; D005341:Fibrinolysin
keywords: 3-Nitrotyrosine; Peroxynitrite; Plasmin