Structure of a novel sialooligosaccharide from the urine of a patient with mucolipidosis.

A mannose-containing sialooligosaccharide has been isolated from the urine of a patient with a newly recognized mucolipidosis which showed a low liver beta-galactosidase activity and hyperglycopeptiduria. The chemical structure has been determined by glycosidase digestion, Smith degradation and permethylation studies. The following structure has been given for the oligosaccharide: NANAalpha2-6Galbeta1-4GlcNAcbeta1-2Manbeta1-3Manbeta1-4GlcNAc. This compound appears to be derived from an incomplete catabolism of glycoproteins with aspartylglucosylamine type side chains.