Electrostatic interactions in concentrated protein solutions
Abstract
We present an approximate method for calculating the electrostatic free energy of concentrated protein solutions. Our method uses a cell model and accounts for both the coulomb energy and the entropic cost of Donnan salt partitioning. The former term is calculated by linearizing the Poisson-Boltzmann equation around a nonzero average potential, while the second term is calculated using a jellium approximation that is empirically modified to reproduce the dilute solution limit. When combined with a short-ranged binding interaction, calculated using the mean spherical approximation, our model reproduces osmotic pressure measurements of bovine serum albumin solutions. We also use our free energy to calculate the salt-dependent shift in the critical temperature of lysozyme solutions and show why the predicted salt partitioning between the dilute and dense phases has proven experimentally elusive.
Cite
@article{arxiv.1304.2481,
title = {Electrostatic interactions in concentrated protein solutions},
author = {Shradha Mishra and Jeremy D. Schmit},
journal= {arXiv preprint arXiv:1304.2481},
year = {2013}
}
Comments
19 pages, 8 figures