Vitamin K-dependent coagulation factors (Factor II, Factor VII, Factor IX, Factor X) (VKDFs)

The Vitamin K-dependent coagulation factors (II, VII, IX, and X) are a group of hepatic-synthesized zymogens essential for the blood coagulation cascade. These proteins undergo a post-translational modification called gamma-carboxylation of specific glutamic acid residues, a process that requires Vitamin K as a cofactor (StatPearls: NBK535377). This modification allows the factors to bind calcium ions and associate with phospholipid membranes, which is critical for their activation and enzymatic function as serine proteases (NIH: NBK507850). In the event of vascular injury, these factors work in a coordinated sequence—Factor VII in the extrinsic pathway, Factor IX in the intrinsic pathway, and Factor X and II (prothrombin) in the common pathway—to ultimately generate thrombin and form a stable fibrin clot (UniProt: P00734). Dysregulation or deficiency of these factors leads to bleeding disorders, while their overactivity contributes to thrombotic diseases such as deep vein thrombosis and stroke. Pharmacological modulation of these factors, primarily through Vitamin K antagonists like warfarin, is a cornerstone of long-term anticoagulant therapy, though it requires careful monitoring due to the narrow therapeutic index and risk of hemorrhage (PubChem: CID 54678486).

Other names

Prothrombin complexVitamin K-dependent clotting factorsGla-domain containing coagulation factors

Vitamin K antagonists inhibit the enzyme Vitamin K epoxide reductase (VKORC1), preventing the recycling of Vitamin K. This results in the production of decarboxylated, inactive forms of Factors II, VII, IX, and X, which cannot bind calcium or phospholipid membranes, thereby halting the coagulation cascade (StatPearls: NBK535377; PubChem: CID 54678486).