CONFORMATIONAL-ANALYSIS OF DISACCHARIDES USING MOLECULAR-DYNAMICS ANDNMR METHODS

The internal dynamics of four disaccharides, a galacturonic acid dimer , beta-ethyl-lactoside, sucralose and arabinobiose, have been studied using molecular dynamics and nuclear magnetic resonance methods. Theor etical motional models, which include order parameters and correlation times for internal motions, were extracted from dynamics trajectories in vacuo. In parallel, theoretical NOESY volumes were calculated from averaged distance matrices using 'model-free' spectral densities. The se data were least-squares fitted to the normalized experimental NOESY volumes using the order parameters and internal motion correlation ti mes as adjustable parameters. The resulting 'experimental' motional mo dels were in good agreement with the theoretical ones with the excepti on of the galacturonic acid dimer which was best described by the rigi d molecule approximation.