Can CHARMM36 atomic charges described correctly the interaction between amino acid and water molecules by molecular dynamics simulations?

Abstract

Here we present calculations of electrical, energetic and magnetic properties of the amino acids arginine, aspartic acid, glutamic acid, histidine and lysine in water solution. The molecules have charged NH31+ and COO1− terminations. The objective is to verify if the atomic charges of the CHARMM36 force field accurately describe the interactions between these amino acids and water, using Molecular Dynamics simulations. For this, the molecules were polarized in solvent medium and we have obtained new atomic charges after the simulations. A comparison of the properties of interest was made using the two charge models and the results show that, in some situations, the updated charge model can better describe the interactions between the analyzed amino acids and the water molecules.