Plasminogen bound to fibrin (PLG-fibrin)

Plasminogen bound to fibrin is a localized molecular complex that plays a central role in the fibrinolytic system, responsible for the dissolution of blood clots. Plasminogen, a zymogen synthesized in the liver, circulates in an inactive closed conformation but undergoes a conformational change to an open state upon binding to the lysine residues of fibrin via its kringle domains [10, 11]. This binding significantly enhances its susceptibility to activation by tissue plasminogen activator (tPA), which also has a high affinity for fibrin, thereby concentrating plasmin generation at the site of the thrombus [1, 4]. The resulting active enzyme, plasmin, then degrades the fibrin matrix into soluble degradation products like D-dimer [8, 10]. This localized activation is the therapeutic basis for fibrin-specific thrombolytic drugs such as alteplase and tenecteplase, which are used to treat life-threatening conditions like acute myocardial infarction and ischemic stroke [3, 6]. However, pharmacological manipulation of this target carries a significant risk of major hemorrhage if systemic plasminogen activation occurs or if physiological hemostatic plugs are dissolved [2, 3].

Other names

Fibrin-bound plasminogenPlasminogen-fibrin complexClot-bound plasminogen

Fibrin-specific activation of plasminogen to plasmin, which subsequently degrades the fibrin matrix of a thrombus into soluble fragments [1, 4, 10].