The Kinin System of Human Plasma VI. The Action of Plasmin

Structural Changes Accompanying Enzymatic Activation of Human Hageman Factor

“…Knowledge of the patterns of cleavage of HHF by enzymes from the plasma will be of considerable help in defining the mechanisms of activation of the molecule in vivo. Activation in solid phase by negatively charged surfaces is not accompanied by cleavage of the molecule (10), while enzymes from the plasma activate and cleave Hageman factor (8,10,11). The importance of the cleavage in directing activity along a particular pathway, i.e.…”

Role of the Contact System in Fibrinolysis

“…159 Brady kinin formation via kallikrein formation can, how ever, clearly occur in the absence of triggers. 12 Also, the formation of the mentioned enzymes by mechanisms other than contact activation itself can stimulate contact activation.…”

Role of surface in surface-dependent activation of Hageman factor (blood coagulation Factor XII)

“…These data, together with the observations that surface-bound HF is rapidly cleaved in plasma during contact activation in glass tubes (20) and that HF in solution can be proteolytically activated by plasmin, kallikrein, Factor XIa, or trypsin (21)(22)(23)(24), stimulated the present quantitative studies of the cleavage of purified human HF by these proteases in the presence and absence of various surface materials and high-Mr kininogen. In this report the limited proteolysis of l25I-labeled HF (125I-HF) was assessed using sodium dodecyl sulfate (NaDodSO4) gel analysis to follow the cleavage of the 80,000 Mr single chain HF zymogen to give fragments of approximately 52,000 and 28,000 Mr.…”