Protein C and protein S

Protein C and protein S are glycoproteins, predominantly synthesized in the liver, that are important components of the natural anticoagulant system in the body. They are Vitamin K dependent and serve as essential components in the maintenance of physiologic hemostasis.

Proteins C is a precursor of the serine protease, activated protein C (APC). Its proteolytic activation by thrombin occurs on the surface of endothelial cells and involves thrombomodulin and endothelial PC receptor (EPCR).

Proteins S acts as a principal cofactor to protein C. The two work together to help regulate and control blood clot formation by inactivating specific coagulation factors (factors V and VIII) that are required to generate and form blood clots.

The protein C anticoagulant system provides important control over the blood coagulation cascade. Any alteration in this pathway, either hereditary, iatrogenic, or otherwise, may interfere with normal coagulation. Deficiencies in protein C and protein S are associated with thrombotic complications.
Protein C and protein S