HFXIa 1111a Human
Factor XIa
Prepared
from Human Factor XI using Human Factor Xlla. This Xlla was
removed using a corn trypsin inhibitor column. Complete activation is
observed by SDS-PAGE. Factor XI, through the contact factor pathway
cascade, is activated to Factor XIa via Factor Xlla and High Molecular
Weight Kininogen. During activation by Factor Xlla and HK, FXI
undergoes proteolytic cleavage in which the Mr=80,000 chain reportedly
is cleaved to a heavy and light chain with Mr of about 48,000 and
33,000. This 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.
Buffer composition = 4
mM Sodium Acetate-HCl/0.15 M NaCl/pH 5.3
*Extinction Coefficient (1%) = 13.1
Molecular Weight = 160,000 daltons
Human Factor XIa Sample Certificate of Analysis