Fig. 6: LODES, chromatograms, and CID spectra of Hex₁₀GlcNAc₂ N-glycans from IgY.

a LODES for the structural determination of Hex₁₀GlcNAc₂ N-glycans. Only the LODES used for identifying isomer 10D is illustrated. The complete LODES of Hex₁₀GlcNAc₂ N-glycans is illustrated in the Supplementary Fig. S6. b Chromatogram (selective ion monitoring of ion m/z 1045) of Hex₁₀GlcNAc₂ N-glycan extracted from IgY. The chromatogram denotes the last separation in two-dimensional HPLC. Two peaks in the chromatogram represent the α and β anomeric configurations of the sugar at the reducing end of the same isomer. c, d CID mass spectra used to identify the structure. The intensity of ion m/z 923 is much higher than that of ion m/z 1085 in (b), indicating the Hex₁₀GlcNAc₂ belongs to groups D or E, according to MS³(1) in (a). The intensity of ion m/z 437 is much higher than that of ion m/z 731 in (c), indicating Hex₁₀GlcNAc₂ is isomer 10D according to MS⁴(1) in (a). The numbers (in green) in the horizontal line at the top of each CID spectrum represent the CID sequence. The number on the top of each peak in CID spectrum represents m/z value, which the structural decisive fragments are highlighted in red boldface.