title: Isolation and characterization of phosphorylated oligosaccharides from alpha-N-acetylglucosaminidase that are recognized by cell-surface receptors.
abstract: Adsorptive endocytosis of lysosomal enzymes by fibroblasts and hepatocytes involves binding to cell surface receptors that recognize on lysosomal enzymes a phosphorylated carbohydrate, most likely a mannose 6-phosphate residue [Kaplan et al. (1977) Proc. Natl Acad. Sci. U.S.A. 74, 2026-2030; Ullrich et al. (1978) Hoppe-Seyler's Z. Physiol. Chem. 359, 1591-1598]. Loss of alpha-N-acetylglucosaminidase endocytosis after treatment with endoglucosaminidase H indicated that the recognition site of alpha-N-acetylglucosaminidase is located on N-glycosidically linked oligosaccharides of the high mannose type. Acidic oligosaccharides with an average molecular weight of 2200 were liberated from alpha-N-acetylglucosaminidase by endoglucosaminidase H. These oligosaccharides were susceptible to degradation by alkaline phosphatase, alpha-mannosidase and beta-N-acetylglucosaminidase. At the non-reducing terminal these oligosaccharides bear phosphorylated mannose and/or N-acetylglucosamine residues.
mesh_terms: D000118:Acetylglucosaminidase / Q000172:deficiency; D002478:Cells, Cultured; D004705:Endocytosis; D005347:Fibroblasts / Q000378:metabolism; D006596:Hexosaminidases / Q000172:deficiency; D006801:Humans; D008099:Liver / Q000378:metabolism; D008358:Mannose; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D009844:Oligosaccharides / Q000378:metabolism*; D010766:Phosphorylation; D011955:Receptors, Drug / Q000378:metabolism*; D012867:Skin / Q000378:metabolism
chemical_list: D009844:Oligosaccharides; D011955:Receptors, Drug; D006596:Hexosaminidases; D000118:Acetylglucosaminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008358:Mannose