Interacting Lewis-X carbohydrates in condensed phase: a first-principles molecular dynamics study

Area of Science:

• Carbohydrate chemistry
• Computational biophysics
• Crystallography

Background:

• Lewis-X (LeX) trisaccharides are crucial glycans involved in cell recognition and adhesion.
• Understanding LeX interactions is vital for elucidating biological processes and designing nanomaterials.

Purpose of the Study:

• To investigate the interacting conformations of Lewis-X trisaccharides in the crystalline phase using first-principles molecular dynamics.
• To characterize the intermolecular forces governing LeX crystal packing and stability.
• To propose candidate structures for in vivo LeX-LeX interactions at cell surfaces.

Main Methods:

• First-principles molecular dynamics calculations at finite temperature.
• Comparison of calculated structural parameters with experimental X-ray diffraction data.
• Analysis of hydrogen bonding and dispersion forces contributing to crystallization energy.

Main Results:

• Calculated cell parameters and atomic structure of LeX agree well with experimental data.
• Identified a hydrogen-bond network mediating LeX pair interactions.
• Quantified the contributions of hydrogen bonds and dispersion forces to crystallization energy.
• Dispersion forces are key for intramolecular conformation and stability.

Conclusions:

• The study provides a detailed molecular understanding of LeX crystal structures.
• Candidate configurations for hydrated, in vivo LeX-LeX interactions at cell surfaces are proposed.
• These findings have implications for understanding cell adhesion and self-assembly of nanostructures.