Homozygous recombinant expression of full-length mutant and WT vWF and coexpression of WT and mutant full-length vWF.

(A) High-resolution SDS–agarose gel electrophoresis under nonreducing conditions identified a majority of bands of monomer (m) and dimer (d) size of mutant vWF compared with fully multimerized recombinant WT vWF. Fainter bands in the range of tetramers were also observed in the mutants. Mutant and WT recombinant vWF under reducing conditions are shown as monomers (right). (B) Medium-resolution SDS–agarose gel electrophoresis of recombinant WT and mutants coexpressed vWF. Two different proportions of WT to mutant transfection plasmid concentrations were used (1:1 and 1:3). Arrows indicate extra intervening bands between triplets observed in the multimer pattern of the vWD 2A/IID mutation and the vWD 3 mutation but not in the pattern of the vWD 2A/IIE mutation. In combination with the reduced HMWM, the multimer phenotype of the patients' plasma is reproduced exactly. The intervening bands and the relative decrease in HMWM were more pronounced in the 1:3 transfection experiment.