The energy landscape of negatively charged BSA adsorbed on a negatively charged silica surface

Tokarczyk, Karolina and Kubiak-Ossowska, Karina and Jachimska, Barbara and Mulheran, Paul A. (2018) The energy landscape of negatively charged BSA adsorbed on a negatively charged silica surface. Journal of Physical Chemistry B. ISSN 1520-6106

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    Abstract

    We study the energy landscape of the negatively charged protein BSA adsorbed on a negatively charged silica surface at pH7. We use fully atomistic molecular dynamics (MD) and steered MD (SMD) to probe the energy of adsorption, and the pathway for the surface diffusion of the protein and its associated activation energy. We find an adsorption energy ~ 1.2 eV, which implies that adsorption is irreversible even on an experimental timescales of hours. In contrast, the activation energy for surface diffusion is ~ 0.4 eV, so that it is observable on the MD simulation timescale of 100 ns. This analysis paves the way for a more detailed understanding of how a protein layer forms on biomaterial surfaces, even when the protein and surface share the same electrical polarity.