Kinetics of plasmin inhibition in the presence of a synthetic tripeptide substrate. The reaction with pancreatic trypsin inhibitor and two forms of alpha 2-plasmin inhibitor.
The progressive inhibition of plasmin by pancreatic trypsin inhibitor and by alpha 2-plasmin inhibitor in the presence of D-valyl-L-leucyl-L-lysine 4-nitroanilide was investigated. The kinetics with plasmin were compared with those with miniplasmin. The kinetic properties of two functionally different forms of alpha 2-plasmin inhibitor described by Clemmensen [(1979) in The Physiological Inhibitors of Coagulation and Fibrinolysis (Collen. D., Wiman, B & Verstraete, M., eds.), pp 131-136, Elsevier, Amsterdam] were characterized. The two forms differ in their plasminogen-binding capability, and this difference can account for a difference in secondary site interaction suggested from the kinetics. The binding of inhibitor to miniplasmin is a simple pseudo-first-order reaction with both pancreatic trypsin inhibitor and the two alpha 2-plasmin inhibitor forms. Such simple kinetics are also observed for the reaction between plasmin and the non-plasminogen-binding form of alpha 2-plasmin inhibitor. More complicated kinetics are obtained for the reaction between plasmin and the alpha 2-plasmin inhibitor form that binds to plasminogen. With both forms of the alpha 2-plasmin inhibitor, a complex stable to acetic acid/urea and gel electrophoresis is present and fully developed 15 s after initiation of the reaction with plasmin.
D007611:Aprotinin / Q000494:pharmacology*; D001665:Binding Sites; D005341:Fibrinolysin / Q000037:antagonists & inhibitors*; D006801:Humans; D007700:Kinetics; D009842:Oligopeptides / Q000378:metabolism*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors; D000979:alpha-2-Antiplasmin / Q000494:pharmacology*
D009842:Oligopeptides; D010446:Peptide Fragments; D000979:alpha-2-Antiplasmin; C033809:lys-plasmin; C019493:miniplasmin; C018788:valyl-leucyl-lysine 4-nitroanilide; D007611:Aprotinin; D005341:Fibrinolysin