The clotting of fibrinogen I. The liberation of peptide material

Fibrinogen Clotting and Fibrino-Peptide Formation by Staphylocoagulase and the Coagulase-Reacting Factor

“…Mihalyi (1950) reported differences in the electrophoretic mobilities of fibrinogen and fibrin when both are dissolved in urea, and Lorand (1952) demonstrated that limited proteolysis accompanies the transformation of fibrinogen to fibrin by showing a 3% increase in nonprotein nitrogen during the reaction. Independent work by others (Bailey and Bettleheim, 1955;Lorand and Middlebrook, 1952) established the fact that the glutamic acid N-terminal residues present in fibrinogen give rise to glycine in fibrin when the clotting of purified fibrinogen occurs. The glutamic acid was recoverable as the N-terminal amino acid of a peptide fraction split off during the transformation.…”

“…Thrombin clotting is now generally accepted as being initiated by limited proteolysis, which cleaves from fibrinogen certain acidic peptides, and which renders the remainder of the fibrinogen molecule capable of secondary polymerization and gel formation (Scheraga and Laskowski, 1957). Lorand (1952) demonstrated the release of nonprotein nitrogen from fibrinogen under the catalysis of thrombin, and others (Bailey and Bettleheim, 1955;Lorand and Middlebrook, 1952) showed that bovine fibrinogen possesses only glutamyl and tyrosyl N-terminal residues, whereas fibrin has tyrosyl and glycyl residues. Blomback and Vestermark (1958) successfully chromatographed the thrombin-induced fibrino-peptides.…”

Amino Acids and Derivatives

“…The residue is taken up on 0.5N hydrochloric acid or in acetic acid (about 1 ml per 10 ILmole protein) and 1 !J.l amounts applied s6 • In order to remove the free amino acids, the residue from evaporation (see above) is dissolved in 2 mll N hydrochloric acid and this solution passed through a column (diameter 2.5 cm) of a mixture of 20 g Hy£lo-Super-Cel and 50 g talcum (pretreated with O.OIN and IN hydrochloric acid [171)). The solution is repeatedly evaporated to dryness, some water being added each time.…”

The significance of variations in immunoreactive and clottable fibrinogen in health and following thrombosis

“…Received for publication 18 July 1971 of peptide units (Bailey and Bettelheim, 1955) now known as fibrinopeptides A and B (Blomback, 1967). Following their detachment, the residual portions of the molecule polymerize to form insoluble fibrin (Fig.…”