VWF-CP–specific proteolytic action on VWF demonstrated by VWF multimer analysis.

NP indicates normal plasma with typical triplet structure (filled arrows); TTP-P, native plasma of a patient with active TTP (note the absence of a defined triplet structure compared with normal plasma); TTP-P + VWF-CP, plasma of a patient with TTP mixed with control plasma of a patient with VWF deficiency but normal protease (note the appearance of a pronounced triplet structure besides loss of large multimers); rVWF, untreated recombinant VWF; rVWF + VWF-CP, proteolyzed rVWF incubated with plasma of a patient with VWD type 3 (empty arrows refer to inner subbands that can also be demonstrated by high-resolution SDS agarose gel electrophoresis of normal plasma VWF); rVWF + TTP-P, rVWF incubated with plasma of a patient with TTP.