Assessing the inhibitory potency of galectin ligands identified from combinatorial (glyco)peptide libraries using surface plasmon resonance spectroscopy

• Published in: Analytical biochemistry Vol. 378; no. 2; pp. 190 - 196
• Main Authors: Maljaars, C. Elizabeth P., André, Sabine, Halkes, Koen M., Gabius, Hans-Joachim, Kamerling, Johannis P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.07.2008
• Subjects: alpha-Fetoproteins - chemistry; alpha-Fetoproteins - metabolism; Amino Acid Sequence; Animals; Asialoglycoproteins - chemistry; Asialoglycoproteins - metabolism; Cattle; Fetuins; Galectin; Galectin 1 - chemistry; Galectin 1 - metabolism; Galectin 3 - chemistry; Galectin 3 - metabolism; Glycomimetic; Glycopeptide; Glycopeptides - chemistry; Glycopeptides - metabolism; Humans; Lectin; Ligands; Molecular Sequence Data; One-bead-one-compound (glyco)peptide library; Peptide Library; Protein Binding; Surface plasmon resonance; Surface Plasmon Resonance - methods; Galectin; Lectin; Glycomimetic; Surface plasmon resonance; Glycopeptide; One-bead-one-compound (glyco)peptide library
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2008.04.023

Combinatorial (glyco)peptide libraries offer the possibility to define effective inhibitors of protein (lectin)–glycan interactions. If a (glyco)peptide surpasses the inhibitory potency of the free sugar, then the new peptide–lectin contacts underlying the affinity enhancement may guide further rational drug design. Focusing on the adhesion/growth regulatory human galectins 1 and 3, a screening of three combinatorial solid-phase (glyco)peptide libraries, containing Gal(β1-O)Thr, Gal(β1-S)Cys/Gal(β1-N)Asn, and Lac(β1-O)Thr, with the fluorescently labeled lectins had led to a series of lead compounds. To define the inhibitory potency of a selection of resynthesized (glyco)peptides systematically, a surface plasmon resonance-based inhibition assay with immobilized asialofetuin was set up. (Glyco)Peptides with up to 66-fold potency relative to free lactose as inhibitor were characterized. The presence of lactose in the most effective glycopeptides indicated the presence of affinity-enhancing peptide–lectin contacts. In addition to drug design, they may be helpful for fine-structural analysis of the binding sites.