TRANSIENT INTERMEDIATES IN THE THROMBIN ACTIVATION OF FIBRINOGEN - EVIDENCE FOR ONLY THE DESAA SPECIES

The structure of a fibrin gel depends on the nature of the fibrinogen activation products produced by thrombin and the physical condition un der which assembly occurs. Two different structures of the intermediat e fibrin protofibril have been proposed, the production of which requi res different extents of fibrinopeptide A (FpA) cleavage from fibrinog en. The fibrin activation intermediates must be stable since time is r equired for the intermediates to diffuse to growing protofibrils. The classic Hall-Slayter model requires cleavage of both FpAs to form a de sAA intermediate. The Hunziker model requires cleavage of only one FpA to form an AdesA intermediate. Electrophoretic quasi elastic light sc attering has been used to show the time dependent production of the re levant fibrinogen activation intermediates that includes desAA but not AdesA.