Glycans are intrinsically flexible molecules that can adopt many conformations. These molecules often carry ionic functional groups that influence glycan’s conformational preferences, dynamics, and aggregation tendencies. Inspired by these mechanisms, we have engineered a glycan sequence whose secondary structure can be precisely manipulated by using ionic groups. We strategically incorporated ionic substituents into a glycan sequence adopting a hairpin conformation. Complementary ionic groups stabilized the closed conformers, while ionic repulsions shifted the populations toward the open forms. External stimuli, such as pH variations or enzyme addition, enabled us to dynamically control the hairpin’s opening and closing. Additionally, changes in protonation states led to glycan aggregation, suggesting opportunities for the creation of responsive glycan-based materials.
