Multifunctional multivalency: a focused library of polymeric cholera toxin antagonists

Area of Science:

• Biochemistry
• Polymer Chemistry
• Microbiology

Background:

• Multivalent ligand interactions with multimeric proteins require structural pre-organization.
• Polymer-based heterobifunctional ligands with prearranged pendant groups can probe receptor active sites.

Purpose of the Study:

• To synthesize and evaluate galactose conjugates on polyacrylamide and dextran as potential inhibitors.
• To investigate the impact of structural pre-organization on ligand activity against cholera toxin.

Main Methods:

• Synthesis of galactose conjugates on polyacrylamide and dextran backbones.
• Conjugation of a second functional fragment to create heterobifunctional ligands.
• Assay of synthesized compounds for inhibitory activity against cholera toxin.

Main Results:

• Galactose conjugates with an additional fragment demonstrated potent inhibition of cholera toxin at nanomolar concentrations.
• Galactose-only precursor molecules showed no significant inhibitory activity.
• The pre-organization of functional groups on the polymer backbone was crucial for high-affinity binding and inhibition.

Conclusions:

• Structurally pre-organized, polymer-based heterobifunctional ligands are effective inhibitors of multimeric protein targets like cholera toxin.
• The design strategy of combining specific functional groups on a polymer scaffold can lead to highly potent therapeutic agents.
• This approach offers a versatile platform for developing inhibitors against various protein targets.