The molecular recognition of a novel kind of hybrid conjugates, composed of artificial biomimetic beta-peptide oligomers with an O-linked natural N-acetyl-galactosamine (the Tn-antigen) residue, by four different GalNAc specific lectins was investigated using surface plasmon biosensor technology. The influence of the peptide and the glycosyl moiety on the recognition was studied using two glycosylated beta(3)-heptapeptides, a glycosylated alpha-heptapeptide, two beta-amino acid containing dipeptides, and monomeric alphaGalNAc-O-Thr. Although all four lectins displayed a decreased affinity for the carbohydrate residue when attached to a peptide, as compared to the monomeric Tn-antigen, the peptide part was found to have distinct effects on the binding kinetics-indicating that varying degrees of protein-peptide interactions occurred in the recognition process. Likewise, the lectins did not discriminate between beta(3)-peptides and the alpha-peptide, but the beta-linkage of the galactose had a detrimental effect for at least two of the lectins.
(c) 2007 John Wiley & Sons, Ltd