Fig. 4.

Mass spectrometric analysis of N-glycans from CD98hc. Glycans released from purified GalMBP ligands were permethylated and subjected to MALDI MS profiling. All labeled molecular ions corresponding to complex-type glycans were subjected to MS/MS analysis. The assignment for each ion represents the most likely structure based on the precise fit between the calculated composition and the m/z value, taking into account the biosynthetic pathways of N-glycosylation in addition to the MS and MS/MS data. Values (m/z) listed correspond to ¹²C throughout. Satellite peaks surrounding major signals are either artifacts of the permethylation process or are minor glycans with one or more sialylated antennae. The symbols are defined in Figure 1.