Effects of fibrinopeptide cleavage on the plasmic degradation pathways of human cross-linked fibrin.

The presence of fibrinopeptide B in human fibrin has a significant effect on plasmic degradation pathways of cross-linked clots. Two types of fibrin were obtained from fibrinogen by incubation either with thrombin, to remove both fibrinopeptides A and B, or with batroxobin, to cleave fibrinopepitde A only. Fibrins obtained after various incubation times were characterized by the determination of the NH2-terminal amino acids, the content of fibrinopeptides, and the extent of cross-linking. The fibrins were digested by plasmin and were analyzed by polyacrylamide gel electrophoresis. The presence and concentration of the (DD)E complex, as well as fragments E1 and E2, in the digests were dependent upon the loss of fibrinopeptide B from cross-linked fibrin. These degradation products, and also fragment DD, appear to be useful molecular markers of fibrinolysis.