HAGEMAN-FACTOR-DEPENDENT FIBRINOLYSIS - GENERATION OF FIBRINOLYTIC-ACTIVITY BY THE INTERACTION OF HUMAN ACTIVATED FACTOR-XI AND PLASMINOGEN

  • 1 January 1979
    • journal article
    • research article
    • Vol. 54  (4) , 850-862
Abstract
Human coagulation factor XI was purified, and upon activation with Hageman factor fragments, converted the fibrinolytic proenzyme plasminogen to plasmin. This proactivator activity was functionally and antigenically distinct from prekallikrein. When .gamma.-globulin plasma fractions deficient in Hageman factor, prekallikrein and factor XI were isolated, factor Xl-deficient plasma possessed 2/3 of the plasminogen proactivator activity of the Hageman factor-deficient plasma, while prekallikrein deficient plasma had only 1/3 of the plasminogen proactivator activity. The Hageman factor-dependent plasminogen proactivator previously reported in the .gamma.-globulin fraction of normal human plasma was a function of prekallikrein and factor XI, while activity observed in prekallikrein-deficient plasma was attributable to factor XI. When compared utilizing iodinated fibrin digestion, prekallikrein and factor XIa had similar potency/active site; they were far less active than urokinase.