Figure 4 of
Han, Mol Vis 2004;
Figure 4. Tandem mass spectrum of the peptide of doubly charged ion at m/z 680.0
This peptide was identified as residues 178-190, YTGAGMNPARSFA with methionine residue 183 being oxidized. The inset (*) represents the nomenclature and structure of peptide fragment ions according to Biemann .