Structure and bonding of aqueous glutamic acid from classical molecular dynamics simulations

Using classical molecular dynamics we have studied the solution structure of (1 : 1 : 29) glutamate with sodium counter ions and water. We provide a structural description of the system, focusing on glutamate-glutamate interactions and providing further insight into glutamate-water interactions. In particular we have characterised the solution structure using three different water potentials, finding little difference between the structural features they predict. We find key differences in the bonding motifs for the two different carboxyl groups, both in the glutamate-glutamate and glutamate-water interactions. Finally, we have examined the hydration structure of the sodium ions in the solution, showing that 10% of the ions are fully hydrated by water, despite the high glutamate concentration.