High performance anion exchange chromatography of reduced oligosaccharides from sialomucins

Abstract

High performance anion exchange chromatography on pellicular ion exchange resins under high pH conditions with detection of sugars using a pulsed amperometric detector has been developed as a method for the separation and analysis of reduced oligosaccharides liberated from mucins by alkaline borohydride treatment. Ovine, bovine and porcine submaxillary mucins were used as models to develop the method. Although neutral reduced di-to tetraoligosaccharides were poorly retained on the column, a variety of sialylated reduced oligosaccharides could be separated efficiently. Treatment of the samples with sialidase and rechromatography identified the sialylated compounds in the elution profile. A striking finding was the greatly delayed elution times given byN-glycolylneuraminic acid containing compounds in comparison with the correspondingN-acetylneuraminic acid containing analogues. The elution profiles for the product from the mucins closely corresponded to those expected for the major oligosaccharides from these mucins. The procedures described will be useful for analysing sialomucins on a microscale without resorting to radiolabelling procedures.