Glycopeptide dendrimers for biomedical applications

Area of Science:

• Carbohydrate chemistry
• Glycobiology
• Medicinal chemistry

Background:

• Lectins are proteins that bind carbohydrates, playing roles in biological processes and disease.
• Fucose-specific lectins, such as Ulex europaeus lectin I (UEA-I) and PA-IIL from Pseudomonas aeruginosa, are targets for diagnostics and therapeutics.
• Developing multivalent ligands can enhance binding affinity and specificity compared to monovalent compounds.

Purpose of the Study:

• To synthesize and screen combinatorial libraries of peptide dendrimers displaying C-fucosyl residues.
• To identify potent and selective ligands for fucose-specific lectins.
• To investigate the influence of dendritic structure and amino acid composition on glycopeptide-lectin interactions.

Main Methods:

• Combinatorial synthesis of peptide dendrimers with varying numbers of C-fucosyl residues.
• Screening of dendrimer libraries for binding to Ulex europaeus lectin I (UEA-I) and PA-IIL.
• Affinity determination using IC50 values and analysis of structure-activity relationships.

Main Results:

• Identified potent ligands for UEA-I (IC50 = 11 microM) and high-affinity ligands for PA-IIL (IC50 = 0.14 microM).
• Demonstrated that glycopeptide dendrimer-lectin binding is modulated by amino acid residues, not solely by the number of attached sugars.
• Developed the first multivalent ligands reported for these specific lectins.

Conclusions:

• Peptide dendrimers are effective multivalent scaffolds for developing potent lectin ligands.
• Amino acid composition significantly influences the binding affinity and selectivity of glycopeptide dendrimers.
• These findings open avenues for targeted drug delivery and diagnostics using glycopeptide dendrimers.