title: The autodigestion of human plasmin follows a bimolecular mode of reaction subject to product inhibition.
abstract: Plasmin is a labile enzyme destroyed by a process termed autodigestion. Studied by a kinetic assay on the substrate Tos-Gly-Pro-Lys-pNA this process is shown to follow a bimolecular mode of reaction, which is retarded by plasmin degradation products. Plasmin is protected by fibrinogen, by epsilon-aminocaproic acid (6-aminohexanoic acid), by increasing ionic strength, and by glycerol. CNBr fragments of fibrinogen did not protect. Lack of substrate protection of plasmin may give rise to errors in a two-stage plasminogen activator assay, while the presence of substrate in a one-stage method prevents degradation of the generated plasmin.
mesh_terms: D015119:Aminocaproic Acid / Q000494:pharmacology; D001667:Binding, Competitive; D005340:Fibrinogen / Q000494:pharmacology; D005341:Fibrinolysin / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009994:Osmolar Concentration; D013696:Temperature
chemical_list: D005340:Fibrinogen; D005341:Fibrinolysin; D015119:Aminocaproic Acid