During the first 24 months, the ENSCC consortium achieved significant scientific and technical milestones, successfully advancing the design, synthesis, and functional exploitation of artificial Carbohydrate-Binding Molecules (CBMs) across three core scientific Work Packages (WP1-WP3).
In WP1 (Design and Synthesis), researchers completed the computational design phase using molecular dynamics, molecular mechanics, and DFT methods to validate receptor geometries. The consortium successfully synthesized diverse libraries of modular CBMs. Key achievements include the development of water-soluble macrocyclic architectures, such as diaminocarbazole-naphthalene scaffolds and "temple" designs, specifically engineered to selectively target both all-equatorial (e.g. glucose) and non-all-equatorial sugars. Additionally, highly tunable aromatic oligoamide foldamers were synthesized. This included cone-shaped foldamers for organic media and water-soluble hemicapsules functionalized with boronic acid groups for aqueous carbohydrate recognition. Complementing these synthetic receptors, cyclic lectin-like peptides (e.g. Odorranalectin analogues) were produced via solid-phase synthesis to mimic natural carbohydrate-binding proteins.
In WP2 (Binding and Analysis), the consortium implemented advanced analytical screening methods to evaluate CBM affinities. Utilizing NMR, Isothermal Titration Calorimetry (ITC), and Circular Dichroism (CD), researchers quantified specific host-guest interactions. Notable achievements include a naphthalene-based macrocycle exhibiting a 1.2 mM affinity for MeβGlc and the deep inclusion of cancer-relevant disaccharides like the TF-antigen. Foldamer-sugar binding was effectively monitored via induced CD signals and slow-exchange NMR. Furthermore, WP2 introduced highly impactful novel methodologies: 19F-NMR tagged galectins for simultaneous, competitive on-cell screening; a new unlabelled NOESY-based NMR pulse sequence for site-specific protein-ligand interaction mapping; and Second Harmonic Generation (SHG) spectroscopy to detect binding on grafted monolayers.
In WP3 (Functional Discovery), these CBMs were translated into practical technologies. For separation and sensing, capsule-shaped foldamers were successfully immobilized onto gold surfaces (Au-S monolayers) to create interfacial recognition platforms. Optical sensing was further supported by the resolution of a 1.4 Å crystal structure of an anthracene-based receptor encapsulating fucose, providing crucial structural validation. For selective chemistry, cone-shaped foldamers were utilized as supramolecular protecting groups to successfully bias acylation patterns on unprotected sugars. Concurrently, aspartic-acid-based organocatalysts were developed, delivering high α-selectivity in glycosylation reactions. Finally, in bio-functionality, researchers demonstrated the binding of Griffithsin proteins to high-mannose viral and fungal targets, and successfully conjugated carbohydrate ligands to 15N-enriched PD-1 mutants, laying the groundwork for targeted immunotherapy and antiviral applications.
