Quantitation of the inhibitory effect of fibrinogen and its degradation products on fibrin polymerization.
Anticlotting activities of fibrinogen and its plasmin degradation products--fragments X,Y and D--have been measured. On the molar basis fragments Y and D are found equally active whereas fragment X acts about 2 times stronger. We suggest that the inhibitory effect depends on a set of specific binding sites characteristic of domain D. As fragment X possesses two such sets its activity is twice as high as that of the single-set fragments Y and D. In spite of its two domains D fibrinogen inhibits clotting much weaker than fragment X. This is probably due to the presence in fibrinogen of large COOH-terminal sections of the two A infinity-chains interfering with the inhibitory effect. The possible role of these A infinity-chain sections in fibrinogen-fibrin system is discussed.
D000818:Animals; D001777:Blood Coagulation; D002417:Cattle; D005337:Fibrin; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism / Q000494:pharmacology*; D005340:Fibrinogen / Q000494:pharmacology*; D046911:Macromolecular Substances; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface
D005338:Fibrin Fibrinogen Degradation Products; D046911:Macromolecular Substances; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; C015214:fibrinogen D fragment; C030568:fibrinogen fragment X; D005337:Fibrin; D005340:Fibrinogen