Carbohydrate-carbohydrate interactions (CCIs) mediate cell-cell adhesion and are involved in processes that include embryo development, metastasis, and myelin compaction. The main focus of this thesis is on myelin sheath CCIs, particularly between either galactose (Gal) or glucose (Glc) with sulfogalactose (SGal). To understand how sugars bind sugars at an individual atom level, various ligand-observed NMR techniques were employed using glycopolymers as a model system. We showed that glycopolymers can serve as the macromolecular component of a saturation transfer difference (STD) NMR experiment using an established recognition model. We also demonstrated how glycoconjugates containing either Gal, Glc or Mannose (Man – negative control) interact with a glycopolymer containing SGal using STD and diffusion ordered spectroscopy (DOSY). Given that glycol molecules play an important role in interactions related to health and disease, we are also interested in understanding the interactions of carbohydrates with proteins. Gal has been previously reported to interact with proteins with aromatic side chains as well as aromatic compounds in solution via CH-π interactions. This thesis also focuses on how these studies have been extended to SGal in solution using chemical shift perturbation (CSP) studies, with methyl-β-D SGal and phenol and indole as models for the interactions. We showed that the magnitude of chemical shift variation is influenced by the size of the aromatic ring as well as the nature of the substituent (electron donating groups (EDGs) vs. electron withdrawing groups (EWGs) on the aromatic ring. Lastly, we provided an aromatic-based view of the CH-π interactions using STD and DOSY NMR as we showed which parts of the aromatic units were involved in interactions with the sugars.
