(A) The native assembly of two monosaccharides leads to eight potential disaccharides, depending on the regioselectivity (e.g., 1,2 versus 1,3) and stereoselectivity (α versus β) of the newly formed glycosidic bond. In contrast, only a single structure is produced from the native assembly of dinucleotides or dipeptides.
(B) Mammalian glycans are composed of nine monosaccharides, which are pictorially represented by specific symbols from the Symbol Nomenclature for Glycans.
(C) Glycosyltransferases utilize activated nucleotide sugar donors to transfer monosaccharide units onto growing glycan chains.