Human Protein S ELISA Kit

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

Protein S also known as PROS1 is a vitamin K-dependent plasma glycoprotein with a molecular mass of approximately 75 kDa. It is synthesized mainly in the liver but also found in other tissues such as the endothelium megakaryocytes and osteoblasts. This protein plays a significant role in the regulation of blood coagulation by serving as a non-enzymatic cofactor for activated protein C (APC) in the proteolytic degradation of coagulation factors Va and VIIIa.

Biological function summary

The integrated function of Protein S within the coagulation cascade cannot be overemphasized. It acts synergistically with APC to limit thrombin generation therefore facilitating anticoagulation. Protein S is part of a complex with APC that exerts a potent anticoagulant effect. While free Protein S shows functional activity a large fraction circulates in complex with C4b-binding protein where it exhibits limited cofactor activity.

Pathways

The anticoagulant role of Protein S anchors it within the critical pathways like the protein C pathway impacting hemostasis. It directly associates with proteins such as Factor Va and Factor VIIIa and indirectly with proteins like thrombin. The regulation of coagulation through these pathways highlights its contribution to maintaining vascular integrity and preventing thrombosis.

Associated diseases and disorders

Protein S deficiency has clinical implications in thrombotic conditions including deep vein thrombosis (DVT) and pulmonary embolism (PE). Such deficiencies can be hereditary or acquired often linked to disorders affecting vitamin K metabolism or liver function. Protein C another key anticoagulant closely interacts with Protein S in these disorders highlighting their collaborative effort in preventing excessive clot formation.