title: Hydration of chloride anions in the NanC Porin from Escherichia coli: a comparative study by QM/MM and MD simulations.
abstract: Chloride anions permeate the bacterial NanC porin in physiological processes. Here we present a DFT-based QM/MM study of this porin in the presence of these anions. Comparison is made with classical MD simulations on the same system. In both QM/MM and classical approaches, the anions are almost entirely solvated by water molecules. However, the average water-Cl(-) distance is significantly larger in the first approach. Polarization effects of protein groups close to Cl(-) anion are sizeable. These effects might modulate the anion-protein electrostatic interactions, which in turn play a central role for selectivity mechanisms of the channel.
authors.affiliation: Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Calandrini
authors.affiliation: Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Dreyer
authors.affiliation: Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Ippoliti
authors.affiliation: Computational Biophysics, German Research School for Simulation Sciences, D-52425 Jülich, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Carloni
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D001665:Binding Sites; D002712:Chlorides / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D018272:Porins / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002712:Chlorides; D029968:Escherichia coli Proteins; C528455:NanC protein, E coli; D018272:Porins; D014867:Water