Adsorption to fibrin of native fragments of known primary structure from human plasminogen.
Limited proteolysis of native Glu-plasminogen with pancreatic elastase produced three major fragments, K1+2#3, K4, K5-light chain (miniplasminogen). Fibrin-binding was determined by clotting fibrinogen in the presence of 125I-labelled fragments and measuring 125I in the washed fibrin and in the supernatant. Of the fragments miniplasminogen showed the highest fibrin-binding, the strength of which was intermediate between those of Glu-plasminogen and Lys-plasminogen. The fibrin-binding of all three fragments was decreased by 6-aminohexanoic acid or tranexamic acid. This decrease was most pronounced with K1+2+3. The fibrin-binding of K1+2+3, but not that of K4 and miniplasminogen was decreased by alpha 2-antiplasmin. The fibrin-binding of K1+2+3 and mini-plasminogen was lower in a plasma clot than in a purified fibrin clot. Our results indicate that each of the three fragments can bind to fibrin. They confirm that an alpha 2-antiplasmin-binding site is located on K1+2+3. Furthermore two of the fragments, namely K4 and K1+2+3 contain lysine-binding site(s).
D001665:Binding Sites; D005337:Fibrin / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000378:metabolism; D010958:Plasminogen / Q000378:metabolism*; D014148:Tranexamic Acid / Q000494:pharmacology; D000979:alpha-2-Antiplasmin / Q000494:pharmacology
D010446:Peptide Fragments; D000979:alpha-2-Antiplasmin; D014148:Tranexamic Acid; D005337:Fibrin; D010958:Plasminogen