Protein Assembly on Surfaces Reflects Intrinsic Ion-Specific Solvent Response to the Surface

June 29, 2021

Prelesnik Highlight Graphic.JPG

(A) When the far-field polarization response of water obtained from molecular simulations of mica and the synthetic protein DHR10-mica6 each in isolation are adjoined, the induced pressure between them can be predicted. Exchanging KCl for NaCl results in a sign change in the interaction. (B,C) Assembly of the engineered protein C98RhuA on mica differs dramatically when KCl (left) and NaCl (right) are used. 

Scientific Achievement

Discovered potential origin for ion-specific behavior of proteins at charged mineral surfaces typically observed in experiments.

Significance and Impact

The results show that solution conditions are integral to surface-directed protein assembly and establish a theory that connects molecular simulations to experimental outcomes.

Research Details

  • Developed a molecular model of muscovite mica that replicates the design of the protein-surface interface. 

  • Applied Local Molecular Field theory to isolate far-reaching solvent organization responses.

  • Developed Landau surface interaction theory to accommodate asymmetrically-polarized surfaces.

  • Differences in solvent response to the mica surface predicted for K+ and Na+ inform the differences in protein binding affinities seen experimentally.

Prelesnik, J., R. Alberstein, S. Zhang, H. Pyles, D. Baker, J. Pfaendtner, J.J. De Yoreo, A. Tezcan, R. Remsing, and C. Mundy. (2021). Ion-dependent protein-surface interactions from intrinsic solvent response. PNAS 118: 1-9. DOI: 10.1073/pnas.2025121118.

Work performed at Pacific Northwest National Laboratory and the University of Washington