Structural, dynamic, and metal-ion binding studies of the core glycopeptides beta-D-Gal-(1----3)-alpha-D-GalNAc----Ser, Thr by 13C-N.m.r. spectroscopy.

13C-N.m.r. spectral data as well as spin-lattice relaxation times (T1 values) are presented for the core glycopeptides beta-D-Gal-(1----3)-alpha-D-GalNAc----Ser, Thr. The binding of Gd3+ to these model compounds containing N-terminal blocking groups and esterified carboxyl groups indicates that the disaccharide contains a rather weak, but unique, binding-site in the vicinity of C-2 of alpha-D-GalNAc (possibly involving N-2', the acetamido carbonyl group, O-3' and/or possibly the glycosidic oxygen atom (O-3)).