Carbohydrate ligand binding

These initial reports showed that functional carbohydrate-mimetic peptides could be found. These peptides acted as ligands for several biologically important proteins, and had potential in the development of therapeutics. Subsequently, peptides that act as molecular mimics of carbohydrates in binding to a wide variety of different receptors have been identified [ 14-44] these are summarized in Table 1 and reviewed in [ 13]. Some of these peptides were able not only to bind to a particular receptor, but also to act as immunologically functional mimics and to induce an anti-carbohydrate immune re-... 

The binding affinity of carbohydrate-mimetic peptides can be quite high, often higher than the natural carbohydrate ligand. Carbohydrate-mimetic peptides do not share any general chemical features, and all amino acid residues are represented there is no evidence for an unusual importance of aromatic residues in mimicry. In several cases, o-amino acids have been incorporated, and unusual amino acids (derived from nonribosomal peptide synthesis) have been found in naturally occurring carbohydrate-mimetic peptides. 

In the purification of lectins, special adsorbents have been employed. The adsorbents have been prepared by attaching specific, carbohydrate ligands to activated supports.41-106,157 An affinity adsorbent prepared from chitobiose and (2-aminoethyl)-Bio-Gel was used to purify the 2-acetamido-2-deoxy-D-glucose-binding lectin from wheat germ. The data for the purification of this lectin are shown in Fig. 6. 

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