  We introduce an implicit solvent Molecular Dynamics approach for calculating
ionic fluxes through narrow nano-pores and transmembrane channels. The method
relies on a dual-control- volume grand-canonical molecular dynamics (DCV-GCMD)
simulation and the analytical solution for the electrostatic potential inside a
cylindrical nano-pore recently obtained by Levin [Europhys. Lett., 76, 163
(2006)]. The theory is used to calculate the ionic fluxes through an artificial
trans-membrane c hannel which mimics the antibacterial gramicidin A channel.
Both current-voltage and current-concentration relations are calculated under
various experimental conditions. We show that our results are comparable to the
characteristics associated to the gramicidin A pore, specially the existence of
two binding sites inside the pore and the observed saturation in the
current-concentration profiles.
