title: In vivo degradation of human fibrinogen A alpha: detection of cleavage sites and release of antithrombotic peptides.
abstract: Several degradation products of fibrinogen have been shown to possess regulatory functions. Using peptide extracts from human blood filtrate, a large number of fibrinogen A alpha fragments was identified. These fragments are generated at known plasmin attack sites and at several novel cleavage sites especially at hydrophobic and basic amino acid residues. One fragment containing the cell attachment site (RGD sequence) of fibrinogen A alpha efficiently inhibits fibrinogen binding and platelet aggregation (IC50:20-50 microM) in vitro. We conclude that in vivo degradation of fibrinogen A alpha results in generation of endogenous antithrombotic peptides with local importance in fibrinolysis and platelet aggregation.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D001665:Binding Sites; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology; D005340:Fibrinogen / Q000378:metabolism*; D005341:Fibrinolysin / Q000378:metabolism; D005344:Fibrinopeptide A / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D009842:Oligopeptides; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; D005344:Fibrinopeptide A; D000244:Adenosine Diphosphate; C047981:arginyl-glycyl-aspartic acid; D005340:Fibrinogen; D005341:Fibrinolysin