360-MHz 1H nuclear-magnetic-resonance spectroscopy of sialyl-oligosaccharides from patients with sialidosis (mucolipidosis I and II)

Abstract

360-MHz proton nuclear magnetic resonance spectra were recorded of 10 sialyl-oligosaccharides isolated form urine of sialidosis patients. Their structures are related to the complex aspareagine-linked glydan chains of glycoproteins. By correlation of these spectra and comparison with spectra of reference glycopeptides and sialy-lactose isomers it was possible to assign all signals belinging to anomeric, mannose H-2, sialic acid H-3 and N-acetyl protons. The number of the constituting monosaccharide residues of the oligomers can be obtained by integration of the above-mentioned singnals. The chemical shifts of the anometic and mannose H-2 proteins give information about the type of glydan structure (mono-, bi-, triantennary) and the presence of terminal sialic acid at eachof the antennas. The chemical shfts of sialic acid H-3 protons are typical for sialic acid residues in 23 or 26 linkage ot galactose.