The conformational preference of a-D-Manp-(1->2)-a-D-Manp-(1->O)-L-Ser has been investigated by one-dimensional 1H,1H T-ROESY expts. and mol.-dynamics simulations with CHARMM22 type of force fields and water as explicit solvent. Proton-proton distances were obtained from the simulations and subsequently exptl. detd. distances could be derived. Measurements were performed on the title compd. as well as on selectively deuterium-substituted analogs synthesized as part of this study to alleviate possible NMR spectroscopic difficulties. A very good agreement was present between the sep. NMR expts. In the subsequent anal. a key nuclear Overhauser effect between the anomeric protons in the two sugar residues was used to assess the conformational dynamics revealed by the mol. simulations. The combined results support a model in which two states are significantly populated as a result of flexibility around the bond defined by the glycosidic torsion angle y. [on SciFinder (R)]