Structure of Nine Sialyl-Oligosaccharides Accumulated in Urine of Eleven Patients with Three Different Types of Sialidosis. Mucolipidosis II and Two New Types of Mucolipidosis

Urines of 11 patients with three different types of mucolipidosis characterized by a total or partial sialidase deficiency, were studied. In all cases, we found an important accumulation of sialyl-oligosaccharides. The structure of 9 of them has been determined: α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)-β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)-β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[α-Man-(16)]β-Man-(14)-GlcNAc, α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[β-Gal-(14)-β-GlcNAc-(12)-α-Man-(16)]β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[β-Gal-(14)-β-GlcNAc-(12)-α-Man-(16)]β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)[α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(14)]α-Man-(13)-β-Man-(14)-GlcNAc, α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(16)]β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[α-AcNeu-(23)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(16)]β-Man-(14)-GlcNAc, α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(13)[α-AcNeu-(26)-β-Gal-(14)-β-GlcNAc-(12)-α-Man-(16)]β-Man-(14)-GlcNAc. All these compounds are products of incomplete catabolism of glycoproteins and result from the action of a new type of β-endo-N-acetylglucosaminidase able to act on sialylated glycoproteins or glycopeptides. The term sialidosis is proposed for these three types of oligosaccharidosis.