Coagulation Factor IX Human

Coagulation Factor IX is an important protein in the process of hemostasis and normal blood clotting as it plays a key role within the coagulation cascade. It is located within the blood plasma as a zymogen, an antecedent to enzymatic function, in its inactivated state. Factor IX is dependent on the presence of Vitamin K, and is activated to a serine protease by the function of Coagulation Factor XIa. Factor XIa cleaves the peptide bond associated with protein activation in Factor IX, leaving Factor IX with two exposed chains, a light chain and a heavy chain. These two chains are held together by several disulfide bonds that reinforce the structure of Factor IX's activated form. After being activated, Factor IX forms a complex with calcium ions, membrane phospholipids and Coagulation Factor VIII to activate Coagulation Factor X. The activation of Factor X then performs a similarly integral step in the blood coagulation cascade. The ultimate result of phenotypically normal coagulation factors is the creation of platelets for normal blood clotting.