Title:  Factor XI 
CAS Registry Number:  9013-55-2 
CAS Name:  Blood-coagulation factor XI 
Additional Names:  PTA;  plasma thromboplastin antecedent 
Literature References:  Participates in the initial phases of blood coagulation.  In normal plasma, factor XI is present in a precursor form and is converted to an active form, factor XIa, which in turn activates factor IX to factor IXa in the presence of Ca2+ ions:  Ratnoff, Davie, Biochemistry 1, 677 (1962); Schiffman et al., Blood 22, 733 (1963); K. Fujikawa et al., Biochemistry 13, 4508 (1974).  Deficiency is characterized by the moderate bleeding symptoms of hemophilia C; by pathological clotting and recalcification times, impaired prothrombin consumption, and delayed thromboplastin formation:  Duckert, Soulier in New Blood Clotting Factors, I. S. Wright et al., Eds. (Schattauer-Verlag, Stuttgart, 1960) pp 145-147, 123-131.  Review on bovine factor XI:  T. Koide, Methods Enzymol. 45B, 65-73 (1976).   |