The role of glycosidically bound mannose in the assimilation of [beta]-galactosidase by generalized gangliosidosis fibroblasts

Abstract

Bovine testicular [beta]-galactosidase is rapidly assimilated by generalized gangliosidosis skin fibroblasts. The enzyme contains equimolar amounts of mannose and glucosamine and strongly binds to concanavalin A-Sepharose. Pretreatment of [beta]-galactosidase with a mannosidase preparation from reduced the rate of assimilation of the enzyme 97%. These data indicate that mannosyl residues play a role in assimilation of the enzyme. This conclusion is supported by observed inhibition of [beta]-galactosidase assimilation by mannose, methyl [alpha]- and [beta]-mannopyranosides, and mannose-containing testicular glycoproteins.