Development of an ab initio MO-MD program based on fragment MO method – an attempt to analyze the fluctuation of protein

In order to analyze the fluctuation of proteins, which plays an important role for folding structure and stability, an ab initio MO-MD program (FMO-HA) based on the fragment MO method has been developed and examined its efficiency in comparison with conventional RHF MO-MD. FMO gives the same potential of dissociation energy between fragments as well as RHF. FMO-HA and RHF MO-MD calculations show similar trajectories and geometrical changes. Furthermore, FMO-HA simulation enables us to elucidate the interaction energy between fragments accompanying with the dynamics. FMO-HA method is an efficient tool to determine the driving force of fluctuation of proteins.