Glycopeptide storage in skin fibroblasts cultured from a patient with alpha-mannosidase deficiency.

Abstract

A B S T R A C T Patients with mannosidosis, an inherited deficiency of lysosomal a-mannosidase, accumulate large amounts of mannose-rich oligosaccharides (the "core" of the carbohydrate units of many glycoproteins) in brain and liver and excrete these partial degradation products in their urine. A profound a-mannosidase deficiency was demonstrated in fibroblasts cultured from a skin biopsy obtained from a child with mannosidosis. Further, abnormal glycopeptides rich in mannose and similar to oligosaccharides found in the patient's urine were isolated from fibroblast extracts by a variety of chromatographic procedures and by virtue of their binding to a concanavalin A-Sepharose 4B

Mannosidosis: Separation and Characterization of Two Acid α-Mannosidase Forms in Mutant Fibroblasts

“…Biochemical studies have demonstrated an accumulation of man nose-rich oligosaccharides in tissues of affected individuals and a generalized deficiency of acidic a-mannosidase activity (1,2,(6)(7)(8). Three major forms of a-mannosidase activity have been described and partially characterized in normal human liver (9)(10)(11)(12).…”