title: [Interaction of plasminogen activator of urokinase type with human serum].
abstract: Effects of blood serum on u-PA (EC 3.4.21.31) fibrinolytic activity were studied. After incubation for one hour at 37 degrees of the enzyme with human blood serum (55-145 IU/ml of blood serum) the enzymatic activity was completely inhibited. At the same time, amido-lytic activity of u-PA, estimated with low molecular substance S2444 as a substrate, was maintained in presence of blood serum. Blood serum inhibitors did not exhibit the specific affinity to u-PA. Serine proteases (trypsin, chymotrypsin and plasmin) competed with u-PA at equimolar concentrations. These inhibitors were inactivated after blood serum preincubation with primary amines methylamine, ethylamine, putrescine, spermidine and spermine (0.1-10 mM). The u-PA-inhibitor complexes were not dissociated in presence of 2.5 mM sodium dodecylsulfate. Trypsin-albumin copolymer bound specifically the blood serum u-PA inhibitors and the fraction adsorbed was electrophoretically characterized as a protein with molecular mass of 185 kDa.
mesh_terms: D001550:Benzamidines / Q000494:pharmacology; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D010960:Plasminogen Activators / Q000037:antagonists & inhibitors / Q000097:blood*; D015849:Plasminogen Inactivators; D011480:Protease Inhibitors / Q000097:blood; D013379:Substrate Specificity; D014357:Trypsin / Q000097:blood; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors / Q000097:blood*
chemical_list: D001550:Benzamidines; D006023:Glycoproteins; D015849:Plasminogen Inactivators; D011480:Protease Inhibitors; D010960:Plasminogen Activators; D014357:Trypsin; D014568:Urokinase-Type Plasminogen Activator; C032157:benzamidine
vernacular_title: Vzaimodeĭstvie aktivatora plazminogena urokinaznogo tipa s syvorotkoĭ krovi cheloveka.