Cleavage of internal deletion substrates. Substrates (65 nM) were incubated (A) with the indicated recombinant proteases (2 nM) for 1 hour, or (B) with plasma ADAMTS13 (0.3 nM) for 2 hours, without (−) or with (+) 10 mM EDTA. Substrates and 28-kDa cleavage products () were detected by gel electrophoresis and Western blotting with anti-GST antibody. Results are representative of 3 independent experiments.