Disaccharide-Presenting Iron(II) Complexes as Synthetic Mimics of Natural Glycan Epitopes for Lectin Recognition

Carbohydrates present on the surface of living cells mediate key biological processes, including viral infection, cell adhesion, and immune response. Mimicking the structural complexity of these naturally occurring sugars is therefore critical for gaining fundamental insights into protein-carbohydrate recognition and for guiding the design of glycomimetic architectures with therapeutic relevance. Covalently linking carbohydrates to molecular inorganic architectures provides a unique strategy for interrogating protein recognition that leverages the structural organization and precision of coordination chemistry. Here, we use inorganic complexes to present disaccharide motifs in facially oriented geometries that provide topologically defined glycan displays. We report a family of air- and water-stable Fe(II)-anchored iminopyridine complexes functionalized with the disaccharides maltose, melibiose, lactose, and mannobiose ([Fe(sacc)3][SO4]) that are prepared through coordination-driven subcomponent self-assembly. All complexes were characterized by 1H NMR, ultraviolet-visible (UV–vis), and infrared (IR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS), dynamic light scattering (DLS), and cyclic voltammetry (CV). Binding of these assemblies was evaluated against a panel of bacterial and human lectins, including maltose-binding protein (MBP), microvirin (MVN), Galectin-1 (Gal-1), and LecA, by isothermal titration calorimetry (ITC), demonstrating the versatility of this platform for probing protein-glycan recognition.