An accelerated molecular dynamics study for investigating protein pathways using the bond-boost hyperdynamics method

Abstract

Molecular dynamics (MD) simulation is an important tool for understanding protein dynamics and the thermodynamic properties of proteins. However, due to the high computational cost of MD simulations, it is still challenging to explore a wide conformational space. To solve this problem, a variety of accelerated MD schemes have been proposed over the past few decades. The bond-boost method (BBM) is one of such accelerated MD schemes, which expedites escape events from energy basins by adding a bias potential based on changes in bond length. In this paper, we present a new methodology based on the BBM for accelerating the conformational transition of proteins. In our modified BBM, the bias potential is constructed using the dihedral angle and hydrogen bond, which are more suitable variables to monitor the conformational change in proteins. Additionally, we have developed an efficient algorithm compatible with the LAMMPS package. The method is validated with the conformational change of Adenylate kinase (AdK) by comparing the conventional and accelerated MD simulation results. Based on the accelerated MD results, the characteristics of AdK are investigated by monitoring the conformational transition pathways and the behavior of interdomain salt bridges. Moreover, the free energy landscape calculated using umbrella sampling confirms all the states identified by the accelerated MD simulation are the free energy minima and the system makes transitions following the path indicated by the free energy landscape. Our efficient approach is expected to play a key role in investigating transition pathways in a wide range of protein simulations.