Mannose 6-sulfate is present in the N-linked oligosaccharides of lysosomal enzymes of Dictyostelium.

The major N-linked, anionic oligosaccharide found on several lysosomal enzymes of Dictyostelium discoideum contains five charges, composed of three sulfate esters and two residues of Man-6-P in phosphodiester linkage. Most of the SO4 was found as Man-6-SO4. This novel sulfated sugar was detected and quantitated by measuring the appearance of 3,6-anhydromannitol following acid hydrolysis and reduction of base-treated, reduced oligosaccharides. If SO4 is removed by solvolysis prior to the base treatment, the anhydrosugar is not formed, indicating that its presence is not an artifact of the procedure. That these oligosaccharides are derived from standard high-mannose-type oligosaccharides indicates that only one or, at most, two Man residues are unsubstituted at the 6-position.