Toward an understanding of the aqueous solubility of amino acids in the presence of salts: a molecular dynamics simulation study

J Phys Chem B. 2010 Dec 16;114(49):16450-9. doi: 10.1021/jp104626w. Epub 2010 Nov 19.

Abstract

Ion-specific effects on the aqueous solubilities of biomolecules are relevant in many areas of biochemistry and life sciences. However, a general and well-supported molecular picture of the phenomena has not yet been established. In order to contribute to the understanding of the molecular-level interactions governing the behavior of biocompounds in aqueous saline environments, classical molecular dynamics simulations were performed for aqueous solutions of four amino acids (alanine, valine, isoleucine, and 2-aminodecanoic acid), taken as model systems, in the presence of a series of inorganic salts. The MD results reported here provide support for a molecular picture of the salting-in/salting-out mechanism based on the presence/absence of interactions between the anions and the nonpolar moieties of the amino acids. These results are in good qualitative agreement with experimental solubilities and allow for a theoretical interpretation of the available data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / chemistry*
  • Molecular Dynamics Simulation*
  • Molecular Structure
  • Salts / chemistry*
  • Water / chemistry*

Substances

  • Amino Acids
  • Salts
  • Water