Robust and accurate computational estimation of the polarizability tensors of macromolecules
Abstract
Alignment of molecules through electric fields minimizes the averaging over orientations, e. g., in single particle imaging experiments. The response of molecules to external ac electric fields is governed by their polarizability tensor, which is usually calculated using quantumchemistry methods. These methods are not feasible for large molecules. Here, we calculate the polarizability tensor of proteins using a regression model that correlates the polarizabilities of the 20 amino acids with perfect conductors of the same shape. The dielectric constant of the molecules could be estimated from the slope of the regression line based on Clausius Mossotti equation. We benchmark our predictions against the quantum chemistry results for the Trp cage mini protein and the measured dielectric constants of larger proteins. Our method has applications in computing laseralignment of macromolecules, for instance, benefiting single particle imaging, as well as for the estimation of the optical and electrostatic characteristics of proteins and other macromolecules.
 Publication:

arXiv eprints
 Pub Date:
 April 2019
 DOI:
 10.48550/arXiv.1904.02504
 arXiv:
 arXiv:1904.02504
 Bibcode:
 2019arXiv190402504A
 Keywords:

 Physics  Chemical Physics
 EPrint:
 5 pages, 2 figures