Fibrinopeptidi

Fibrinopeptidi are small peptides that are released from fibrinogen during the process of blood coagulation. Fibrinogen, a soluble protein circulating in the blood plasma, is converted into fibrin, an insoluble protein that forms the meshwork of a blood clot. This conversion is catalyzed by the enzyme thrombin. Thrombin cleaves specific peptide bonds in the fibrinogen molecule, releasing the fibrinopeptidi. There are two main types of fibrinopeptidi: fibrinopeptide A (FpA) and fibrinopeptide B (FpB). Fibrinopeptide A is released first from the N-terminus of the alpha chain of fibrinogen, followed by fibrinopeptide B from the N-terminus of the beta chain. These released peptides are important because their removal exposes polymerization sites on the fibrinogen molecule, allowing the fibrin monomers to aggregate and form the stable clot. Fibrinopeptidi are generally considered byproducts of coagulation and are cleared from the circulation. However, elevated levels of fibrinopeptidi in the blood can be indicative of increased fibrinolytic activity or disseminated intravascular coagulation. Research has also explored potential biological roles for fibrinopeptidi beyond their role in clot formation, though these are less well-established.