Microlyse degrades platelet-VWF complexes. (A) Plasminogen activation by Microlyse in the presence of globular VWF (VWF), open VWF (VWF & ristocetin), or vehicle (ristocetin). (B) Plasminogen activation by Neg-Microlyse in the presence of globular VWF (VWF), open vWF (VWF & ristocetin), or vehicle (ristocetin). (C). Time to half maximal plasmin activity (in minutes). (D) Maximal rates of fluorogenic substrate conversion (ΔRFU/sec). (C,D) Data represent the mean ± SD of 3 separate experiments. Comparisons were made by 2-way ANOVA with Bonferroni’s multiple comparison test. (E) Lysis of ristocetin-induced platelet agglutinates by Microlyse variants (20.7 nM; added at t = 6 minutes, indicated by dotted lines) in absence or presence of (1.16 μM) plasminogen. Data are representative of 3 separate experiments. (F) Lysis times (ie, time to reach 50% agglutinate lysis after addition of compounds). Data represent the mean ± SD of 3 separate experiments. Comparisons were made to Neg-Microlyse by 1-way ANOVA with post hoc Dunnett's multiple comparison test. (G) Disruption of ristocetin-induced platelet agglutination by caplacizumab* (20.7 nM; added at t = 6 minutes, indicated by dotted lines). (H) Lysis times (ie, time to reach 50% agglutinate lysis after addition of caplacizumab*). Data represent the mean ± SD of 3 separate experiments. Comparisons were made by unpaired Student t test with Welch’s correction.