Anti-FXI antibody [MM0193-7C38]

Supplementary info

Activity summary

Factor XI (FXI) also known as Factor 11 or Factor Eleven is an important protein in the human body involved in blood coagulation. It has a molecular mass of approximately 160 kDa and is primarily expressed in the liver. Factor XI circulates in the blood as a zymogen an inactive enzyme precursor until it is activated during the coagulation process. Its activation is a critical step in the chain of events leading to blood clot formation. FXI can be measured using assays such as ELISA and it is often used in laboratory settings to study coagulation mechanics.

Biological function summary

FXI plays a significant role in the intrinsic pathway of the coagulation cascade. It forms a complex with high-molecular-weight kininogen and prekallikrein on the surface of activated platelets ensuring that the coagulation process proceeds efficiently. Upon activation by Factor XIIa FXI itself becomes an active serine protease known as FXIa which then converts Factor IX into its active form Factor IXa. This step highlights the importance of FXI in amplifying the coagulation process ensuring rapid and effective hemostasis.

Pathways

Factor XI is deeply integrated into the intrinsic coagulation cascade. It works alongside other proteins such as Factor XII and Factor IX to facilitate the formation of a blood clot. The intrinsic pathway is essential for maintaining hemostasis particularly in response to internal injuries within the blood vessels. Its interaction with these proteins allows for a powerful amplification of the clotting signal ensuring a robust clot formation and effectively sealing vascular injuries.

Associated diseases and disorders

Dysfunction or deficiency in FXI can lead to bleeding disorders such as Hemophilia C although this is less common than Hemophilia A or B. Interestingly elevated levels of FXI are sometimes associated with an increased risk of thrombotic conditions such as deep vein thrombosis or stroke. In these conditions FXI interacts with other coagulation factors like Factor IX and Factor XII highlighting its dual role in both bleeding and clotting disorders. Understanding FXI's role provides insight into therapeutic targets for managing these conditions.