Fibrinogen breakdown products

Abstract

Enzymatic degradation of fibrinogen or fibrin produces two products termed D and E, and perhaps a third E', which have immunological determinates similar to the mother proteins. On electrophoresis (pH 8.6), D remains at the origin and E moves toward the anode. Fibrinogen, but not fibrin, breakdown results in the appearance of a thrombin-fibrinogen clot inhibitor. This inhibitor appears to be identical to fibrinogen-D as both are heat labile and both are found in the same electrophoretic and gel filtration fractions. Fibrin-D is heat stable. Continuous-flow electrophoresis of incoagulable fibrinogen-enzyme mixtures results in the separation of D, E, and a third immunologically similar fragment called E'. Gel filtration suggests that the molecular weight of D is 200,000 or greater and that of E is 100,000 or greater.