Fig. 4.

MRM-based kinome assay provided robust quantification results. A, Linear regression comparing quantification results of abundant kinase peptides from two melanoma cells obtained by MRM assay and shotgun proteomics analysis. B, Quantitative results by MRM assay for peptide ETSVLAAAK#VIDTK from SLK kinase: Extracted-ion chromatograms for three transitions monitored for light-labeled (Red) and heavy-labeled (Blue) peptides ETSVLAAAK#VIDTK in forward (Left) and reverse (Middle) labeling reactions; The consistent distribution of the peak area observed for each monitored transition from light- and heavy- labeled peptides in both forward and reverse labeling reaction along with the theoretical distribution derived from MS/MS spectra store in MRM kinome library (Right).