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Updated: Aug 7, 2026

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
Published on: August 26, 2025
Molecular conformations of a disaccharide investigated using NMR spectroscopy
Clas Landersjö1, Baltzar Stevensson, Robert Eklund
1Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, S-106 91, Stockholm, Sweden.
Abstract:
The molecular structure of alpha-L-Rhap-(1--> 2)-alpha-L-Rhap-OMe has been investigated using conformation sensitive NMR parameters: cross-relaxation rates, scalar 3J(CH) couplings and residual dipolar couplings obtained in a dilute liquid crystalline phase. The order matrices of the two sugar residues are different, which indicates that the molecule cannot exist in a single conformation. The conformational distribution function, P(phi, psi) related to the two glycosidic linkage torsion angles phi and psi was constructed using the APME method, valid in the low orientational order limit. The APME approach is based on the additive potential (AP) and maximum entropy (ME) models. The analyses of the trajectories generated in molecular dynamics and Langevin dynamics (LD) computer simulations gave support to the distribution functions constructed from the experimental NMR parameters. It is shown that at least two conformational regions are populated on the Ramachandran map and that these regions exhibit very different molecular order.
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