fibriiniset

Fibrinogen is a soluble plasma protein that plays a crucial role in the clotting process. It is synthesized primarily by the liver and is a component of the coagulation cascade. Fibrinogen is a dimer, consisting of two identical subunits, each composed of three non-identical polypeptide chains (Aα, Bβ, and γ). Its primary function is to form a fibrin clot when activated by thrombin, which converts fibrinogen into insoluble fibrin. This fibrin network traps red blood cells and other cellular debris, forming a stable clot that stops bleeding.

Fibrinogen is a glycoprotein, with carbohydrate groups attached to the Aα and Bβ chains. These carbohydrate groups are essential for the proper folding and function of fibrinogen. The Aα chain contains a reactive site that binds to thrombin, initiating the conversion of fibrinogen to fibrin. The Bβ chain contains a binding site for factor XIII, which cross-links fibrin fibers, enhancing clot stability.

Fibrinogen levels in the blood are tightly regulated and can be influenced by various factors, including liver disease, inflammation, and certain medications. Low fibrinogen levels, known as hypofibrinogenemia, can lead to excessive bleeding, while high levels, known as hyperfibrinogenemia, can increase the risk of thrombosis. Genetic mutations in the fibrinogen gene can also result in abnormal fibrinogen function, leading to bleeding disorders such as hemophilia A.

In summary, fibrinogen is a vital protein in the coagulation cascade, responsible for forming a stable fibrin clot that stops bleeding. Its levels in the blood are tightly regulated, and abnormalities in fibrinogen function can lead to bleeding disorders or an increased risk of thrombosis.