Figure 3.

MS sum spectrum (retention time 10.2–14.4 min; 94 spectra) showing the major glycoforms of the N₁₆₂ site. Interestingly, ammonia adducts were exclusively observed for glycopeptides carrying an oligomannose glycan, while iron adducts were detected for both oligomannose and complex structures. For more details on MS/MS spectrum see Figure S9. *: N₁₆₂ glycopeptides with a miscleaved peptide backbone; #: unidentified glycopeptide (z = 2); and $: iron adducts [M+Fe^III]³⁺. NVS: CRGLVGSKN₁₆₂VSSE peptide backbone.