Aggregation of Fibrinogen and Its Degradation Products by Basic Proteins

Abstract

SummaryFibrinogen and early fibrinogen degradation products (FDP) of plasmin digestion containing Fragment XfP gave highly ordered polymers of limited branching with protamines and synthetic polylysine (molecular weight 175,000). Histones, polylysine of molecular weight 2,500, granulocyte cationic protein and platelet factor 4 formed amorphous precipitates with fibrinogen and early FDP. Fibrin degradation products (fdp) containing complexes of Fragment X° formed highly ordered polymers of extensive branching with these basic proteins.The splitting off of fibrinopeptides from fibrinogen and Fragment XfP was not essential for the formation of highly ordered polymers. However, in the presence of fibrinopeptides, high specificity of polymerizing agents such as basic protein is required. In the absence of fibrinopeptides, fibrin monomer or Fragment X° could polymerize after dissociation from complexes with other degradation products by any of the basic proteins.It has been suggested that the polymerization of fibrinogen and its derivatives by basic proteins may be an important factor contributing to the formation and deposition of fibrin-like material in clinical conditions connected with the destruction of tissues (release of histones), damage of granulocytes (release of lysosomal cationic protein) and intravascular formation of platelet aggregates (release of platelet factor 4).

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