Figure 4.

Glycopeptide analysis of rAAV6 by LC-MS/MS with hybrid electron-transfer/higher-energy collision dissociation fragmentation

(A) Schematic of identified glycans and glycosylation sites. O-GlcNAc is depicted as a blue square, O-GalNAc as a yellow square, galactose as a yellow circle, sialic acid as a magenta diamond, and HexNAc as a white square. (B) Extracted ion chromatograms of D184–A212 modified with two oxidation and mucin-type O-glycan clusters. The signal of peptide with HexNAc (m/z 961.1129 ± 0.005) is colored black, HexNAcHex (m/z 1015.1305 ± 0.005) blue, HexNAc₂ (m/z 1028.8060 ± 0.005) red, HexNAc₂Hex (m/z 1082.8236 ± 0.005) green, HexNAcHexNeuAc (m/z 1112.1623 ± 0.005) orange, HexNAc₂HexNeuAc (m/z 1179.8554 ± 0.005) purple, HexNAcHexNeuAc₂ (m/z 1209.1941 ± 0.005) red, and HexNAc₂HexNeuAc₂ (m/z 1276.8872 ± 0.005) magenta. (C) The EThcD mass spectrum of D184–A212 modified with HexNAc₂Hex.