Kinase specificity of PRT060318 and activity on human platelet function. (A) Integrilin-treated human washed platelets were incubated with 2 μL of various concentrations of PRT060318 (all in 30% DMSO) before activation with CVXN (150 ng/mL). Platelet lysates were subjected to SDS-PAGE gels, and Western blots were probed with anti-pLAT pY191 or pSyk pY525/526 antibodies. (B) Quantification of protein bands was performed using densitometry (Epson Expression 1680) using Quantity One Version 4.5.0 software (Bio-Rad Laboratories), and variations normalized to control bands (absence of PRT060318) were plotted against PRT060318 concentrations. (C) Representative dose response effect of PRT060318 on heat-aggregated IgG-induced platelet aggregation (n = 3; IC₅₀ = 85nM in washed platelets). In PRP, PRT060318 inhibits collagen-induced platelet aggregation CD40L (D) and RANTES (E) release. Ept indicates eptifibatide; and Indom, indomethacin. For further data on PRT060318 specificity, please see Reilly et al.²⁷