title: Glycosidases: inborn errors of glycosphingolipid catabolism.
abstract: Glycosphingolipids (GSLs) are information-rich glycoconjugates that occur in nature mainly as constituents of biomembranes. Each GSL contains a complex carbohydrate chain linked to a ceramide moiety that anchors the molecule to biomembranes. In higher animals, catabolism of GSLs takes place in lysosomes where sugar chains in GSLs are hydrolyzed by exo-glycosidases to cleave a sugar residue from the non-reducing end of a sugar chain. Inborn errors of GSL-catabolism, collectively called sphingolipidoses or GSL-storage diseases, are caused by the deficiency of exo-glycosidases responsible for the degradation of the specific sugar residues at the non-reducing termini in GSLs. This chapter briefly discusses glycone, anomeric, linkage, and aglycone specificities of exo-glycosidases and some of the historical landmarks on their associations with the chemical pathology of the five best known sphingolipidoses: GM1 gangliosidosis, GM2 gangliosidosis (Tay-Sachs disease), Fabry disease, Gaucher disease, and Krabbe disease.
authors.affiliation: Faculty of Biology-Oriented Science and Technology, Kinki University, Kinokawa-shi, Wakayama, 649-6493, Japan, ashida@waka.kindai.ac.jp.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ashida
authors.forename: Yu-Teh
authors.initials: YT
authors.lastname: Li