MOLECULAR-DYNAMICS STUDY OF CONFORMATIONAL EQUILIBRIA IN AQUEOUS D-GLUCOSE AND D-GALACTOSE

The free energy differences between three conformations of D-glucose a nd D-galactose (GG/GT/TG) were calculated from molecular dynamics simu lations using the standard GROMOS force field as well as an extended a ll-atom version. It is shown how comparison with results from nuclear magnetic resonance (NMR) measurements can lead to improvements in the force field. Specifically, the exocyclic twofold O-C-C-O dihedral forc e constant should be increased by 0.6 kcal mol(-1) for the standard GR OMOS force field and by 0.9 kcal mol(-1) for the extended version. (C) 1997 Elsevier Science B.V.