Figure 5.

Ladder sequencing of the A2F glycopeptide. A solution of the A2F glycopeptide was divided into eight aliquots and digested by the exoglycosidase array given in Table 2. Mass differences between some of the digestion product peaks are indicated. Symbolic structures are shown for the carbohydrate portion of the starting glycopeptide and for the smallest glycopeptide fragments resulting from the series of exoglycosidase digestions (A–H). Monosaccharides are represented by symbols: ▪, N-acetylglucose; •, galactose; ○, mannose; ◂, sialic acid; ▵, fucose. For clarity, the peptide portion of the glycopeptide is omitted from the symbolic structures.