New calculation method permits more realistic simulation of ion transport

1. Transporting molecules andions through small pores WHY IT MATTERS: The transport of atoms and molecules occurs in an enormous variety of systems. Water is desalinated or decontaminated using porous membranes. Ions are transported through the walls of the cells that make up our body. In many of these situations, the particles that are transported carry an electrical charge, which makes it much harder to understand their interactions with the pore through which they pass. Our simulation technique makes it possible to perform more accurate calculations. Since the method is incorporated in an existing package, it becomes available to a wide community of researchers. PRINCIPAL INVESTIGATOR: E. Luijten (UIUC) New calculation method permits more realisticsimulation of ion transport RESULTS:The transport of ions, and also larger molecules such as DNA, through membranes involves the passage of charged particles through a medium that is polarizable. During this transport, the induced polarization charges evolve dynamically, in an interplay with the mobile charge carriers. For simplicity, the polarizability is ignored in most computer simulations, even though there is strong evidence that it affects the rate at which molecules move through narrow pores. Via a newly implemented self-consistent calculation method we have now demonstrated how the ion distribution changes within a nanopore through which DNA is translocated, modifying the force felt by such molecules in an external electric field. Transport of ions through nanopores:We use a new calculation method tobetter understand the transport of charged particles through nanopores