title: Inhibition of urokinase by complex formation with human antithrombin III in absence and presence of heparin.
abstract: Human antithrombin III was purified from fresh human plasma by affinity chromatography on heparin-Sepharose, affinity chromatography on concanavalin A Sepharose, gel filtration on Ultrogel AcA 34, ion exchange chromatography on DEAE A-50 Sephadex and preparative agarose gel electrophoresis. The hydrolytic activity of urokinase (plasminogen activator from urine) on acetyl-glycyl-L-lysine methylester acetate (Ac-gly-lys-OMeAc) was inhibited by antithrombin III in a slow time-dependent manner. Heparin accelerated the reaction between activator and inhibitor. Inhibition of catalytic activity was associated with the formation of an 1:1 molar complex between activator and inhibitor as revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The complex was also demonstrated by crossed immunoelectrophoresis against anti-antithrombin III.
mesh_terms: D000936:Antigen-Antibody Complex; D000990:Antithrombin III / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D011480:Protease Inhibitors; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors*
chemical_list: D000936:Antigen-Antibody Complex; D011480:Protease Inhibitors; D000990:Antithrombin III; D006493:Heparin; D014568:Urokinase-Type Plasminogen Activator