Title: Fibrin
CAS Registry Number: 9001-31-4
Literature References: Fibrin monomer is fibrinogen from which one or two peptides have been removed by means of thrombin: Laki, Chandrasekhar,
Nature 197, 1267 (1963). The term fibrin is usually applied to polymerized fibrin monomer. Terminal clotting takes place in four steps: (1) fibrinogen hydrolyzes under the influence of thrombin into fibrin and fibrinopeptide fragments; (2) fibrin forms soft clots which can be readily dispersed; (3) thrombin activates fibrin-stabilizing factor,
q.v., an enzyme precursor, present in blood plasma; (4) fibrin in the networks cross-links under the influence of the activated FSF to give the final hard clots:
Chem. Eng. News 43, no. 32, 38 (1965); O. D. Ratnoff, B. Bennett,
Science 179, 1291 (1973). Fibrin occurs in two principal forms,
fibrin-i, "insoluble" fibrin, differing from
fibrin-s, "soluble" fibrin, by urea solubility as well as other characteristics. Fibrin-i is formed through the reaction of a fibrinogen-like plasma protein, FSF, which in the presence of Ca2+ converts what would otherwise be a "soluble" weakly bonded gel into a covalently bonded, insol clot: Rosenberg, Carman,
Nature 204, 994 (1964). Chemical studies of crosslinking segments: Chen, Doolittle,
Proc. Natl. Acad. Sci. USA 66, 472 (1970);
eidem, Biochemistry 10, 4486 (1971); Doolittle
et al., Biochem. Biophys. Res. Commun. 44, 94 (1971).
Reviews: W. H. Seegers,
Prothrombin (Harvard University Press, 1962) 728 pp; Laki, Gladner,
Physiol. Rev. 44, 127 (1964); Lorand,
Fed. Proc. 24, no. 4, part 1, 784 (1965); A. L. Copley,
Thromb. Res. 14, 249 (1979). Review of chemistry: several authors,
Thromb. Diath. Haemorrh. Suppl. 39 (1970).