Charge Distribution and Surface Properties of the Tobacco Mosaic Virus 4-nm Central-Pore

The uniform distribution of charged amino acids along the exterior surface of the tobacco mosaic virus (TMV) along with its unusual structural stability over a large pH and temperature range has made it a model organism for inorganic deposition and nanostructure fabrication studies on biomolecules. However, the potential engineering applications of the virus’s central pore, which is about 300 nm long and 4 nm in diameter, has been overlooked. We aim to expand TMV applications by understanding the surface characteristics of its central pore. We have identified the set of amino acids and atoms that create the surface of the pore, mapped the partial charge distribution of the pore using AMBER9 force fields, and determined the electrostatic potential of the pore surface through Coulomb’s law and Poisson-Boltzmann Equation (PBE). Our analysis has revealed that the pore contains a dense helical distribution of negatively charged glutamic amino acid residues, which results in a strong negative electrostatic potential across the pore. This can potentially be used for water filtration by creating overlapping electric double layer within the central pore.