The epitope(s) recognized by HNK-1 antibody and IgM paraprotein in neuropathy is present on several N-linked oligosaccharide structures on human P0 and myelin-associated glycoprotein.
The mouse monoclonal antibody HNK-1 and the human monoclonal IgM antibody present in patients with polyneuropathy both recognize carbohydrate epitope(s) on human myelin-associated glycoprotein and P0. In the present study, the oligosaccharide structures that bear the antibody epitope(s) were investigated. The extracellular derivative of myelin-associated glycoprotein (dMAG) was purified by immunoaffinity chromatography. P0 was electroeluted from gel slices. Western blot analysis of whole glycoproteins demonstrated that the epitopes for HNK-1 and the human monoclonal IgM antibody were different. The glycopeptides obtained by proteolysis of purified dMAG and P0 were separated and characterized by affinity chromatography on concanavalin A-Sepharose. Both dMAG and P0 displayed heterogeneity in their oligosaccharide structures, i.e., they both contained mainly tri- and tetraantennary oligosaccharides (approximately 80%), although biantennary (10%) and high-mannose and/or hybrid (10%) oligosaccharides were present. The human monoclonal IgM antibody epitope was present on all types of isolated oligosaccharide structures from either dMAG and P0. The HNK-1 epitope was present on all types of oligosaccharide structures of dMAG, whereas it was present only on tri- and tetraantennary structures of P0.
Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
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D
Burger
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Simon
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Perruisseau
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AJ
Steck
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology*; D015153:Blotting, Western; D018959:CD57 Antigens; D000939:Epitopes; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D008562:Membrane Glycoproteins; D018993:Myelin P0 Protein; D009185:Myelin Proteins / Q000276:immunology*; D018992:Myelin-Associated Glycoprotein; D009422:Nervous System Diseases / Q000276:immunology*; D009844:Oligosaccharides / Q000276:immunology; D010266:Paraproteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D018959:CD57 Antigens; D000939:Epitopes; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D018993:Myelin P0 Protein; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D009844:Oligosaccharides; D010266:Paraproteins