Proteolysis of full-length VWF by ADAMTS13. (A) Recombinant WT VWF and VWF Leu1603Ala and Leu1603Ser were examined for their multimer composition using SDS-agarose gel electrophoresis and Western blotting for VWF. (B) Proteolysis of recombinant full-length WT VWF, VWF Leu1603Ala, and Leu1603Ser (1.0 μg/mL) by 20 nM ADAMTS13. Changes in VWF were examined by SDS/PAGE under reducing conditions with Western blotting for VWF. (C) Proteolysis of full-length WT VWF (1.0 μg/mL) by 15 nM WT ADAMTS13 and ADAMTS13 Val195Ser, Leu198Ser, and Leu274Ser variants examined by SDS/PAGE with Western blotting, as in B.