Anomalous Protein-Protein Interactions in Multivalent Salt Solution

0475326 - ÚOCHB 2018 RIV US eng J - Journal Article
Pasquier, C. - Vazdar, M. - Forsman, J. - Jungwirth, Pavel - Lund, M.
Anomalous Protein-Protein Interactions in Multivalent Salt Solution.
Journal of Physical Chemistry B. Roč. 121, č. 14 (2017), s. 3000-3006. ISSN 1520-6106. E-ISSN 1520-5207
R&D Projects: GA ČR(CZ) GA16-01074S
Institutional support: RVO:61388963
Keywords : Monte Carlo * molecular dynamics * membranes * proteins * multivalent salts
OECD category: Physical chemistry
Impact factor: 3.146, year: 2017

The stability of aqueous protein solutions is strongly affected by multivalent ions, which induce ion-ion correlations beyond the scope of classical mean-field theory. Using all-atom molecular dynamics (MD) and coarse grained Monte Carlo (MC) simulations, we investigate the interaction between a pair of protein molecules in 3:1 electrolyte solution. In agreement with available experimental findings of ”reentrant protein condensation”, we observe an anomalous trend in the protein-protein potential of mean force with increasing electrolyte concentration in the order: (i) double-layer repulsion, (ii) ion-ion correlation attraction, (iii) overcharge repulsion, and in excess of 1:1 salt, (iv) non Coulombic attraction. To efficiently sample configurational space we explore hybrid continuum solvent models, applicable to many-protein systems, where weakly coupled ions are treated implicitly, while strongly coupled ones are treated explicitly. Good agreement is found with the primitive model of electrolytes, as well as with atomic models of protein and solvent.
Permanent Link: http://hdl.handle.net/11104/0272157