Protein Assembly on Surfaces Reflects Intrinsic Ion-Specific Solvent Response to the Surface
June 29, 2021
(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.
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.
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.