The Influence of Fibrin on the Reaction of Plasminogen Activation by Mut ant of Pro-Urokinase / 生物化学与生物物理进展

Because the influence of fibrin on the reaction of plasm inogen activation by various plasminogen activators is different, the kinetic co nstant of the reaction of plasminogen activation catalyzed by InB with and witho ut fibrin were detected. The result is: Kfibrinm＝4.2 μmol*L -1，greater than the normal Km=0.379 μmol*L-1; kfib rincat＝0.107 s-1，greater than the normal kcat=0.0165 s-1. The results suggest that existence of fibrin in the reaction system of plasminogen activation depress the affinity between InB and plasminog en, but accelerates the hydrolysis of plasminogen by InB. The count up effect is inhibition.