Structural analysis of the carbohydrate chains of a mouse monoclonal IgM antibody.
A mouse monoclonal IgM antibody, directed against human blood group B determinant, was isolated from hybridoma culture growth medium. Chemical analysis indicated presence of N- and O-linked oligosaccharides. The N- and O-linked carbohydrate chains were liberated using two different conditions of reductive alkaline degradation. Structural analysis was carried out on the isolated chains using chemical analysis, 500-MHz 1H-NMR spectroscopy and fast-atom-bombardment mass spectrometry. The following composite structures of the N-linked chains were found: (formula; see text) where R = OH for biantennary structures and R = Neu5Ac alpha 2-3Gal beta 1-4 GlcNAc beta 1- or Neu5Ac alpha 2-3Gal beta 1-3[Neu5Ac alpha 2-6]GlcNAc beta 1- for triantennary structures. The O-linked oligosaccharides, found in the light chains, were shown to have the structure Neu5Ac alpha 2-3Gal beta 1-3GalNAc. The native IgM antibody could be separated on a concanavalin-A-Sepharose column into two subfractions, differing in the presence of a high-mannose-type oligosaccharide.
Department of Carbohydrate Chemistry, University of Lund, Sweden.
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Krotkiewski
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Nilsson
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Svensson
D000017:ABO Blood-Group System / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006801:Humans; D007075:Immunoglobulin M / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D051379:Mice; D009844:Oligosaccharides / Q000302:isolation & purification
D000017:ABO Blood-Group System; D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D009844:Oligosaccharides