title: The reducing end of alpha Gal oligosaccharides contributes to their efficiency in blocking natural antibodies of human and baboon sera.
abstract: Synthetic galactosyl oligosaccharides were tested for their ability to inhibit the cytotoxic reaction of human and baboon natural antibodies on PK15 cells in culture. Methyl-alpha-Gal gave weak inhibition, Gal alpha 1-3Gal substantially inhibited the reaction (400muM), and Gal alpha 1-3Gal beta 1-4GLcNAc was ten times more efficient (30 muM). The modification from alpha to beta anomeric configuration of the nonreducing end resulted in a complete loss of activity, while substitutions at the reducing end induced only a partial loss of activity. These observations suggest that natural anti-alphaGal antibodies recognize the epitope from its nonreducing end, but that substitutions at the reducing terminus can modify the antibody-binding capacity. Modified tri- and tetrasaccharides are better inhibitors than the disaccharide but not as good as Gal alpha 1-3Gal beta 1-4GlcNAc. The reducing terminus therefore contributes some energy to the reaction, indicating that certain oligosaccharides will be of more potential clinical use than others.
authors.affiliation: Oklahoma Transplantation Institute, Baptist Medical Center, Oklahoma City 73112-4481, USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Neethling
authors.forename: D
authors.initials: D
authors.lastname: Joziasse
authors.forename: N
authors.initials: N
authors.lastname: Bovin
authors.forename: D K
authors.initials: DK
authors.lastname: Cooper
authors.forename: R
authors.initials: R
authors.lastname: Oriol
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D016645:Aotidae; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D009844:Oligosaccharides / Q000276:immunology* / Q000378:metabolism*; D010215:Papio; D013552:Swine; D014183:Transplantation, Heterologous / Q000276:immunology*
chemical_list: D000906:Antibodies; D009844:Oligosaccharides