Fig. 2.

Structure of glycans. Lettering (a-n) follows the order of addition of monosaccharides in the synthesis of Glc3Man9GlcNAc2-P-P-dolichol. Glucosidase I removes residue n and GII residues l and m. GT adds residue l to residue g. The Man8GlcNAc2 isomer A (M8A) lacks residues g and l-n.