Contribution of component monosaccharides to the coordinates of neutral and sialyl pyridylaminated N-glycans on a two-dimensional sugar map.

High-performance liquid chromatography elution data on an amide-adsorption and a reverse-phase column, expressed in glucose units, of pyridylamino N-glycans have been analyzed with a new approach using multiple regression to obtain parameters for the contribution ascribable to each of 54 monosaccharide units. Our calculation was based on the 417 different N-glycan structures determined empirically. Depending on the increase in the amount of elution data, we got good correlation (r = 0.9998 for amide-silica and r = 0.9974 for octadecylsilica) and agreement between the observed and the calculated N-glycan elution coordinate values which correspond to the sum of the unit contribution of the component monosaccharides. These calculated values of unit contribution are useful in predicting glycan structure from an observed glucose unit on the map as well as to assume a glucose unit from a given structure. As an example of the application of the unit contribution values to the estimate of a sialyl N-glycan structure, the case of trisialyl triantennary N-glycans is described.