Simulation-Aided Characterization of Biomimetic Separation Membrane for Water Purification

Water desalination is a process of great technological importance that is carried out with remarkable efficiency in living cells via the membrane proteins Aquaporin.  This study presents results from an investigation carried out on Aquaporin-1 (AQP1) protein using molecular dynamics (MD) simulation. An initial result reported here addresses the theory of water molecules permeation through AQP1 and the difference between osmotic permeability p_f and diffusion permeability p_d of a single-file water channel.   Chemical potential difference of water established across the AQP1 channel resulted with a p_f of 6.3 x 10^-14 cm³/s.  Equilibrium MD simulation runs resulted with a calculated p_d of 5.7 x 10^-15 cm³/s.  Reported values for p_d and p_f, both are in close agreement with observation, are of prime importance for future membrane design and scale-up for water desalination purposes.