Towards understanding the interaction between oligosaccharides and water molecules

Area of Science:

• Carbohydrate Chemistry
• Biophysics
• Computational Biology

Background:

• Complex carbohydrates (oligosaccharides) play vital roles in biological processes.
• Their structure and dynamics are closely linked to interactions with water molecules.
• Understanding these interactions is key to deciphering oligosaccharide function.

Purpose of the Study:

• To investigate the interactions at oligosaccharide linkages using molecular dynamics simulations.
• To correlate linkage orientation and sugar epimerization with water interactions.
• To understand how these factors influence oligosaccharide structure and dynamics.

Main Methods:

• Molecular dynamics simulations with explicit water.
• Analysis of interactions at alpha and beta linkages in various oligosaccharides.
• Focus on mannose and glucose residue interactions.

Main Results:

• Alpha linkages (2-, 3-, 6-position) interact via weak hydrogen bonds and water-bridges, influenced by sugar epimerization.
• Alpha linkages can interact with noncontiguous residues, forming ordered structures by excluding water.
• Beta linkages (3-, 4-position) form strong hydrogen bonds, interact mainly with adjacent sugars, and have limited water-bridging ability.

Conclusions:

• Alpha-linked sugar sequences form compact, flexible, branched structures.
• Beta-linked sugar sequences form extended, rigid structures, suitable for structural roles and protein-bound termini.
• Chemical structure and water interactions are linked to the emergent form and function of oligosaccharides.