Relationship between VWF and anhydro-APC in FVIII interaction.

(A) Effect of VWF on FVIII binding to anhydro-APC. Serial dilutions of VWF were incubated with FVIII (100 nM) for 2 hours at 37°C prior to the addition to immobilized anhydro-APC. Bound FVIII was detected using peroxidase-conjugated MoAb JR8 as described in “Materials and methods.” (B) Effect of anhydro-APC on FVIII binding to VWF. Serial dilutions of anhydro-APC were incubated with FVIII (4 nM) for 2 hours at 37°C prior to the addition to immobilized VWF. Bound FVIII was detected using peroxidase-conjugated MoAb JR8 as described in panel A.