Synthetic C-oligosaccharides mimic their natural, analogous immunodeterminants in binding to three monoclonal immunoglobulins

The binding of three monoclonal antigalactan immunoglobulins, IgAs X24, J539 and X44 to their natural haptens methyl beta-D-galactopyranosyl-(1-->6)-beta-D-galactopyranoside, and the corresponding tri- and tetrasaccharides, was compared to the binding of these immunoglobulins with the comparable C-linked oligosaccharide analogues 1-3. The near identity of affinities of the two sets of oligosaccharides indicated the absence of any hydrogen bond involvement by the intersaccharidic oxygen atoms in the natural immunodeterminants.