Molecular simulations of dopamine in a lipid bilayer

This study concerns atomistic simulations of dopamine in a fully hydrated lipid bilayer consisting of dipalmitoylphosphatidylcholine (DPPC) molecules. To be more specific, molecular dynamics and umbrella sampling simulations are performed for the detailed investigation of how dopamine behaves in the lipid phase. The latter simulations aim at the computation of the potential of mean force of dopamine from the lipid to the aqueous phase along the normal to the two leaflets of the membrane. From such simulations, useful thermodynamic quantities may be calculated. As far as the molecular dynamics simulations are concerned, the dopamine molecule is initially placed in the water phase, and the time evolution of the whole system under consideration is studied in terms of selected properties, such as various mass density profiles and the existence of hydrogen bonding between dopamine and the other molecules of the simulated system.