MPαC induces washed human platelet activation. (A) Sequences of the myristoylated peptide MPαC containing the C-terminal 9 amino acid residues of human GPIbα and scrambled control peptide MPαCsc. (B) Representative traces of MPαC-induced washed human platelet aggregation (left) and the quantification of maximal aggregation rate (right; n = 5 independent experiments). (C-D) MPαC-induced PAC-1 binding (C) and P-selectin exposure (D) on washed human platelets (n = 5 independent experiments). (E) MPαC-induced ATP release in washed human platelets (n = 6 independent experiments). (F) MPαC-induced PS externalization on washed human platelets (n = 5 independent experiments). One-way analysis of variance (ANOVA) followed by Dunnett post hoc test (compared with MPαCsc) in panels B-F. Data are shown as mean ± standard error of the mean (SEM) in panels B-F. ∗P < .05, ∗∗P < .01, and ∗∗∗P < .001.