Analysis of pyridylaminated O-linked sugar chains by two-dimensional sugar mapping.

Two-dimensional HPLC mapping of O-linked sugar chains was studied. Twenty-seven pyridylamino (PA-) derivatives of O-linked sugar chains liberated from glycoproteins by hydrazinolysis-N-acetylation were separated by reversed-phase and size-fractionation HPLC. Combining the elution positions obtained by these two HPLC techniques allows the construction of a two-dimensional sugar map which can be used to analyze the structure of PA-O-linked sugar chains. As in the case of PA-N-linked sugar chains, the additivity rule which correlates chemical structures with elution positions was also found in the case of PA-O-linked sugar chains. This separation system was effectively applied to the elucidation of minute amounts of PA-O-linked oligosaccharides.