title: Fibrinopeptide B and aggregation of fibrinogen.
abstract: Removal of fibrinopeptide B from human fibrinogen by reaction with the procoagulant enzyme from copperhead snake venom below 25 degrees C resulted in tight aggregation of the fibrinogen, which, in turn, progressively blocked a concomitant but sluggish release of fibrinopeptide A by the enzyme. When the clots obtained at less than 25 degrees C were warmed, they dissociated into soluble aggregates and monomers. Release of fibrinopeptide A then resumed, and a secondary coagulation followed. The aggregation induced by release of fibrinopeptide B itself involves a plasmin-susceptible segment located just distal to B in the B beta chain of fibrinogen, a segment previously shown to be of little importance in the aggregation induced by release of fibrinopeptide A.
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003435:Crotalid Venoms / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D005341:Fibrinolysin / Q000378:metabolism; D005344:Fibrinopeptide A / Q000378:metabolism; D005345:Fibrinopeptide B / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D011485:Protein Binding; D013696:Temperature
chemical_list: D003435:Crotalid Venoms; D005344:Fibrinopeptide A; D005345:Fibrinopeptide B; D005340:Fibrinogen; D005341:Fibrinolysin