Integrative structural glycobiology: From molecular recognition to dynamic multivalent assemblies

Protein-carbohydrate recognition plays an important role in structural biology. Glycans store molecular information through their monosaccharide makeup, stereochemistry, linkage positions, branching, substitutions, and three-dimensional shapes. Glycans are often flexible and structurally diverse, and their interactions are typically individually weak. As a result, glycan recognition in biology usually cannot be described as a single, static ligand fitting into a protein binding pocket. Instead, it depends on a mix of factors, including glycan shape, protein structure, hydration, electrostatic forces, molecular movement, context, density, and multivalency. These factors have led structural glycobiology to shift from focusing only on isolated high-resolution structures to using both experimental and computational data to build models that span different spaces and times. This review examines the main ideas behind this shift. It highlights what makes carbohydrate recognition different from other ligand-protein interactions. It offers a practical, evidence-based way to interpret structural models.