Figure 5.

Efficiency of production of the diagnostic ion for K27_PTM within sequence K27_PTMSAPATGGVKme2KPHR, when PMT is ac, cr or lact and the peptide is variably propionylated. The percentage of intensity of the diagnostic ion in the MS/MS spectrum leading to peptide identification has been plotted in function of the peptide propionylation level (fully propionylated, only modified at K37, not propionylated, or only thus modified at its N-terminus). The nature of the PTM and the charge state (CS) of the precursor ion have been taken into account as variables. Crosses (x) indicate that no identification has been obtained in the considered states (propionylation state, PTM nature, CS).