Kinase activity of full-length T212R BCR-ABL. Native BCR-ABL and T212R mutant BCR-ABL were overexpressed in HEK293 cells and immunoprecipitated in triplicate. Kinase assays were performed in triplicate at the indicated substrate concentrations, and the enzyme velocity was plotted as a function of peptide concentration. BCR-ABL levels were quantified from anti-ABL immunoblots of immunoprecipitated native and T212R mutant BCR-ABL and used to normalize levels of protein used in the kinase assay.