Skip to main content
. Author manuscript; available in PMC: 2008 Nov 1.
Published in final edited form as: J Proteome Res. 2007 Sep 28;6(11):4230–4244. doi: 10.1021/pr070313u

Figure 4. ERPA (CID / ETD) analysis of the tetraphosphorylated peptide from the Lys-C digest of β-casein.

Figure 4

A: Base peak ion chromatogram. B: CID-MS2 spectrum of the m/z 1160.12 (3+) ion eluted at 61.03 min. C: ETD-MS2 spectrum of the m/z 1160.12 (3+) ion eluted at 61.04 min. D: CRCID-MS3 scan of the m/z 1740.04 ion (from the ETD spectrum as indicated by the dotted circle). The peptide sequences with the observed fragment ions are shown in the insert: phosphoserines are indicated as pS. The neutral losses of phosphate are also shown.