ABSTRACT
The complete definition of the primary structure of glycans involves: the identification and determination of the constituent monosaccharides eventually including the type, number, and location of noncarbohydrate substituents such as the methyl and phosphoryl groups; the sequential arrangement of monosaccharide units as well as the linkage between these units and the definition of the anomeric configuration of the glycosidic bonds; and the definition of the nature of the glycan-peptide linkage. The chapter argues that lectins represent an excellent tool not only for isolating glycoproteins but also for furnishing valuable information on the primary structure of glycans. For analysis of the monosaccharide composition, the glycans are generally subjected to methanolysis, followed by a re-N-acetylation, trimethylsilylation, and gas-liquid chromatography or gas-liquid chromatography-mass spectrometry. The biosynthesis of N-glycans is identical in lower and higher animals, as well as in plants and fungi.
