Human coagulation Factor XIa
Human Factor XIa is prepared from Human Factor XI using Human Factor Xlla. Factor Xlla is removed using a corn trypsin inhibitor column. Factor XI is activated to Factor XIa by Factor Xlla and High Molecular Weight Kininogen in the contact pathway of the coagulation cascade. FXI undergoes proteolytic cleavage in which the 80,000 chain reportedly is cleaved to a heavy and light chain with molecular weights of about 48,000 and 33,000. Factor XIa is responsible for the activation of Factor IX to Factor IXa. Unlike other examples of activation of Vitamin K-dependent blood-clotting proteins, Factor XIa proteolysis of Factor IX does not require membrane surfaces. Complete activation and >95percent purity is observed by SDS-PAGE. Prepared from plasma found negative by FDA accepted methods for Anti-HIV1/2, Anti-HTLV I & II, HBsAg, Anti-HCV, Syphilis, HBC Ab, HIV-1 p24 Ag or HIV-1 RNA, HCV RNA and HBV RNA. Donors are screened for CJD (Creutzfeldt-Jakob Disease).