Creation of stable biomimetic nanopores in view of sea water desalination

• Staple technology to keep stable functional polypeptides. • Stabilization of polypeptide structure inside solid-state membrane. • Creation of biomimetic functional membrane. • Full computed study of membrane work using molecular dynamic simulations. In this study, we address one of the key challenges of the 21st century, namely access to clean water. Its availability is expected to decrease, with a potential shortage of potable water in the coming years. Current water desalination technologies are limited due to their high costs and high energy consumption and we need sustainable solutions based on bio-inspired functional for the future. In this work, we envisage the creation of artificial ion channels mimicking natural biological channels. We use a synthetic material (i.e. carbon nanotubes) to minimize energy consumption in a desalination system, coupled with a transmembrane polypeptide called gramicidin A (gA). Cautions should be cared to transfer proteins into artificial nanopores, as the environment differs from that of lipid membranes. In this study, we present molecular dynamics simulation showing stapling strategies to optimize the gA conformation and to maintain the stability of the polypeptide when inserted into the nanopore. The findings highlight that specific residue constraints (i.e. (ALA3_LEU10) and (LEU4_TRY11)) stabilize the protein, with less denaturation in small-diameter CNTs, and the study shows the potential of CNT-based systems for water desalination in nanofluidic. The analyses of the root-mean-square deviation (RMSD) of the gA conformation as well as the transport of water and ions through the gA channel, with or without applied electric field, are investigated and show some interesting features for future applications.