SCHIZOSACCHAROMYCES-POMBE PRODUCES NOVEL PYRUVATE-CONTAINING N-LINKEDOLIGOSACCHARIDES

The large N-linked oligosaccharides released by endo-beta-N-acetylgluc osaminidase H from Schizosaccharomyces pombe glycoproteins were analyz ed for the presence of noncarbohydrate functional groups. No phosphate , sulfate, or acetate could be detected; however, approximately six mo lecules of pyruvic acid/molecule were found on 98% of the oligosacchar ides. Pyruvate moieties were acetal (ketal)-linked to galactose residu es in the R configuration to carbons 4 and 6. This is the first report of pyruvate functional groups being attached to N-linked oligosacchar ides in yeast and appears only to be the second documentation of this sugar modification in eukaryotes.