Conductance measurements of the transmembrane porin protein OmpF as a function of pH and bath concentration have been made with both a microfabricated silicon substrate device and a commercially available polystyrene aperture. Ion transport through the channel was simulated in atomic detail: the measured current was compared with theoretically calculated current, using a Brownian Dynamics kernel coupled to the Poisson equation by a P3M force field. The explicit protein structure and fixed charge distribution in the protein are calculated using the molecular dynamics code, GROMACS. Reasonable agreement is obtained in the simulated versus measured conductance over the range of experimental concentrations studied.
ASJC Scopus subject areas
- Physics and Astronomy(all)