Thrombin

Thrombin is a serine protease that converts fibrinogen into fibrin and activates platelets and several blood-clotting factors, helping form a stable clot.

Prothrombin: Prothrombin is the inactive precursor protein cleaved to produce thrombin. Its conversion is the final activation step that generates thrombin.
Serine protease: A serine protease is an enzyme that cleaves peptide bonds using an essential active-site serine. Thrombin belongs to this enzyme family and uses its catalytic serine to cut clotting proteins.
Dabigatran: Dabigatran is an oral anticoagulant that directly inhibits thrombin. It prevents thrombin from converting fibrinogen and activating other substrates.
Hemostasis: Hemostasis is the process that stops bleeding through vessel responses, platelet activity, and coagulation. Thrombin coordinates platelet activation and fibrin formation within this process.
Coagulation cascade: The coagulation cascade is a sequence of reactions that generates enzymes and cofactors to form a blood clot. Its common pathway produces thrombin from prothrombin.
Proteolytic cleavage: Proteolytic cleavage is the breaking of a protein’s peptide bond by an enzyme. Thrombin activates substrates by cutting specific peptide bonds.
Hirudin: Hirudin is a peptide anticoagulant from leeches that binds thrombin with high affinity. It is a natural, direct inhibitor used as a model for thrombin-targeting drugs.
Thrombosis: Thrombosis is the formation of an abnormal blood clot within a blood vessel. Excessive or misplaced thrombin activity can promote pathological clot formation.
Fibrinogen: Fibrinogen is a soluble blood-plasma protein that thrombin cleaves into fibrin monomers. It is thrombin’s principal clot-building substrate.
Catalytic triad: A catalytic triad is a three-residue arrangement that enables chemical catalysis in many enzymes. Thrombin’s active site uses a catalytic triad to cleave its substrates.

Linked from 8 pages