Figure 10.16 N-linked oligosaccharides. A pentasaccharide core (shaded gray) is common to all N-linked oligosaccharides and serves as the foundation for a wide variety of N-linked oligosaccharides, two of which are illustrated: (A) high-mannose type; (B) complex type. Detailed chemical formulas and schematic structures are shown for each type (for the key to the scheme, see Figure 10.17). Abbreviations for sugars: Fuc, fucose; Gal, galactose; GalNAc, N-acetylgalactosamine; GlcNAc, N-acetylglucosamine; Man, mannose; Sia, sialic acid.