Fig. 4.

MS/MS spectrum of the four example peptides. The matched fragment ions of precursor ions were listed in the right of MS/MS spectra. All the matched ions were labeled with different colors, b-ions were labeled with red color, y-ions were labeled with blue color. The sequences below the spectra were the corresponding full length SEPs according to the Mouse Merged database. Red highlights represent the detected peptide fragments. A The spectrum result of SEP3. B The spectrum result of SEP12. C The spectrum result of SEP33. D The spectrum result of SEP54