Proteolytic cleavage of recombinant vWF expressed in BHK cells. Autoradiograph of a 1.5% SDS agarose gel probed with ¹²⁵I-labeled anti-vWF. Recombinant WT vWF (lanes 1 through 3), R834W vWF mutant (lanes 4 through 6), and R834Q vWF mutant (lanes 7 through 9), purified from the culture media of transfected BHK cells, were incubated with either TBS (lanes 1, 4, and 7) or with 1 U/mL of the plasma proteinase for 15 minutes (lanes 2, 5, and 8) and 30 minutes (lanes 3, 6, and 9).