Fig. 3: Endo H treatment distinguished high-mannose and hybrid structures from complex and paucimannose N-glycans.
From: Mammalian brain glycoproteins exhibit diminished glycan complexity compared to other tissues
The intensity of the 15 most abundant N-glycan masses from a representative male mouse cortex sample is shown after treatment with different glycosidases, grouped by high-mannose (green), hybrid (blue), mixed (pink), or complex and paucimannose structures (gray), with glycan names shown below (F - fucose; G - galactose; S - sialic acid; A - antenna; B - bisected; and H - hybrid). The y-axis (arbitrary units; au) represents the signal intensity (arbitrary units; au) for each mass measured directly from the MALDI without normalization and scaled such that Man-5 (A and B) and FA1B (A and C) were equal for visual comparison. Distinct isomers corresponding to the same mass are shown in brackets. A Treatment with PNGase F removed all N-glycans. B Treatment with Endo H removed only high-mannose and hybrid N-glycans. A placeholder (#) is included because the Endo H fragment corresponding to F2A1G1BH4 is indistinguishable from that of the same glycan without a core fucose (F1A1G1BH4), due to Endo H cleavage between the two core GlcNAc residues and proximal to the core fucose. This results in only one structure present in the +Endo H spectra corresponding to two unique parent glycans. C) PNGase F treatment after Endo H removed complex and paucimannose N-glycans, which were insensitive to Endo H treatment.
