Molecular dynamics studies of proteins and nucleic acids

The computer simulation method of molecular dynamics is extremely expensive in terms of computer power and is therefore in practice limited to time spans of the order of 0.1-1.0 ns. Some progress is being made in the development of methods that can describe events on a longer time scale than that permitted by direct simulation. One source of error is the inaccuracy of present-day force fields, particularly if water is not explicitly included as a solvent. Applications for which these inaccuracies have less important consequences involve the use of molecular dynamics in structure refinement based on experimental data from either NMR or X-ray diffraction. The application of these methods is at present quite popular and methodological improvements are being actively pursued.