Structural characterization of the oligosaccharides of a human monoclonal anti-lipopolysaccharide immunoglobulin M.
The oligosaccharide side chains of a human anti-lipopolysaccharide IgM produced by a human-human-mouse heterohybridoma were analyzed at each of its five conserved N-glycosylation sites. This antibody also has a potential sixth N-glycosylation site in the variable region of its heavy chain which is not glycosylated. The oligosaccharides were released by digestion with various endo- and exoglycosidases and analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and fluorophore-assisted carbohydrate electrophoresis. The antibody has various complex- and hybrid-type oligosaccharide structures at Asn 171, various sialylated complex-type oligosaccharides at Asn 332 and 395, and high-mannose-type oligosaccharides at Asn 402 and 563. Of note is the presence in this human IgM of oligosaccharides containing N-glycolylneuraminic acid and N-acetylneuraminic acid in the ratio of 98:2 as determined using anion-exchange chromatography. Furthermore, we observed oligosaccharide structures containing Gal alpha (1,3)Gal that have not been reported as components of human glycoproteins.
Leibiger
H
H
Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA.
Kersten
B
B
Albersheim
P
P
Darvill
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D006020:Glycopeptides / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D006825:Hybridomas; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry; D007147:Immunoglobulin Light Chains / Q000737:chemistry; D007075:Immunoglobulin M / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry
D000911:Antibodies, Monoclonal; D006020:Glycopeptides; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D009844:Oligosaccharides; D011994:Recombinant Proteins