Influence of oligosaccharide presentation on the interactions of carbohydrate sequence-specific antibodies and the selectins. Observations with biotinylated oligosaccharides.
This study was aimed at investigating the efficacy of presentation of biotinylated oligosaccharides on streptavidin-coated microwells for interactions with (a) three monoclonal antibodies directed at sialyl-Lewisa (Le(a)) or sulfo-Le(a)-related sequences, and (b) the endothelium-leukocyte adhesion molecules, the E-, L- and P-selectins which recognize both the sulfo- and sialyl-Le(a) series. With the antibodies it was observed that if the biotinylated oligosaccharide incorporated the entire antigenic determinant, and additional saccharide length was not included, the biotinyl tag spacer length was a critical factor in the strength of the binding signal. If oligosaccharide chain beyond the determinant was included, the biotinyl tag spacer length was less important. The E-selectin binding data with the biotinylated sialyl- and sulfo-oligosaccharides were in overall accord with previous knowledge. With the L- and P-selectins, however, unexpectedly low binding signals were elicited by biotinyl sulfo-Le(a) sequences relative to those with the sialyl-analogs. This suppression was more pronounced with the rodent than the human L-selectin. Such differential availabilities of oligosaccharides displayed on streptavidin may relate to biological situations, such as the differential reactivities of the three selectins with a given oligosaccharide ligand presented on different carrier proteins, or on different O-glycan cores on mucin-type glycoproteins.
Leteux
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The Glycosciences Laboratory, Imperial College School of Medicine, Northwick Park Hospital, Harrow, Middlesex, UK.
Stoll
M S
MS
Childs
R A
RA
Chai
W
W
Vorozhaikina
M
M
Feizi
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001710:Biotin; D006801:Humans; D051379:Mice; D009844:Oligosaccharides / Q000276:immunology*; D019087:Selectins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D009844:Oligosaccharides; D019087:Selectins; D001710:Biotin