Figure 4.

MS analysis of MPO glycopeptides covering Asn-483, demonstrating the presence of paucimannose-type glycosylation. A, chromatographic separation of each of the peptide glycoforms as used for the relative quantification of the peptide glycoforms. Greyed out values indicate nonglycopeptide signals within the same retention time window. B, averaged MS¹ spectra across the retention time window with Asn-483–specific precursor ions (±15–18 min). C, HCD-product–dependent of the paucimannose glycopeptide at m/z 1045.92. D, HCD-product–dependent EThcD fragmentation of the phosphorylated glycopeptide at m/z 1045.92.