Molecular weight of human factor VIII procoagulant activity

Abstract

Low molecular weight factor VIII procoagulant activity has been prepared by agarose gel chromatography of highly purified human factor VIII using 0.24 M CaCl 2 buffer. The sedimentation properties of this procoagulant activity in sucrose density gradient centrifugation studies carried out at physiologic ionic strength were consistent with a 6.7S protein. These experiments demonstrate that the elution pattern of factor VIII activity in agarose gel chromatography with high ionic strength buffers is due to separation of low molecular weight material — rather than artifactual retention of large molecules within the gel bed — and that the low molecular weight portion of the large factor VIII complex is sufficient for procoagulant function.