Recognition of type 1 chain oligosaccharides and lacto-series glycolipids by an antibody to human secretory component.
Binding of the mouse IgM antibody 6C4 is lost after treatment of human free secretory component with peptide N-glycosidase F (Bakos et al. (1991) J. Immunol. 146, 162-168) or periodate, suggesting that asparagine-linked oligosaccharides contain the epitope recognized by this antibody. Inhibition of antibody binding to free secretory component by milk oligosaccharides established that lacto-N-tetraose is the minimum structure recognized by the antibody, but larger oligosaccharides with terminal Gal beta 1-3GlcNAc sequences bind with much higher affinity. Antibody binding is enhanced by substitution with the Lewis Fuc alpha 1-4 and is inhibited by Fuc alpha 1-2Gal substitution. Free secretory component, however, does not bind other antibodies that recognize Le(a) or Leb oligosaccharides, and binding is lost after digestion with a beta-galactosidase that cleaves Gal beta 1-3 linkages but not after digestion with alpha-L-fucosidase. Therefore, the major epitope recognized by 6C4 on free secretory component is probably not an asparagine-linked Le(a) oligosaccharide. The antibody also binds to human milk lactoferrin, some human mucins, and lacto-series glycolipids including III4 alpha Fuc-lactotetraosyl ceramide and lactotetraosyl ceramide. Based on affinity chromatography of oligosaccharides released from free secretory component, the epitope recognized by antibody 6C4 is present on approximately 3.5% of the asparagine-linked oligosaccharides.
Yu
H
H
Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-1500, USA.
Sipes
J M
JM
Cashel
J
J
Bakos
M A
MA
Goldblum
R M
RM
Roberts
D D
DD
D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001667:Binding, Competitive; D015153:Blotting, Western; D002240:Carbohydrate Sequence; D002846:Chromatography, Affinity; D004848:Epithelium / Q000276:immunology; D000939:Epitopes; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007781:Lactoferrin / Q000276:immunology; D007983:Lewis Blood Group Antigens / Q000276:immunology; D051379:Mice; D008892:Milk / Q000276:immunology; D008969:Molecular Sequence Data; D009077:Mucins / Q000276:immunology; D009844:Oligosaccharides / Q000276:immunology*; D019056:Receptors, Polymeric Immunoglobulin / Q000276:immunology*; D012635:Secretory Component / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006017:Glycolipids; D007075:Immunoglobulin M; D007983:Lewis Blood Group Antigens; D009077:Mucins; D009844:Oligosaccharides; D019056:Receptors, Polymeric Immunoglobulin; D012635:Secretory Component; D007781:Lactoferrin