abstract
Although the understanding of ion specific effects on the aqueous solubilities of biomolecules is crucial for the development of many areas of biochemistry and life sciences, a consensual and well-supported molecular picture of the phenomena has not yet been established. Mostly, the influence of cations and the nature of the molecular interactions responsible for the reversal of the Hofmeister trend in aqueous solutions of amino acids and proteins are still defectively understood. Aiming at contributing to the understanding of the molecular-level mechanisms governing the cation specific effects on the aqueous solubilities of biocompounds, experimental solubility measurements and classical molecular dynamics simulations were performed for aqueous solutions of three amino acids (alanine, valine, and isoleucine), in the presence of a series of inorganic salts. The evidence gathered suggests that the mechanism by which salting-in inducing cations operate in aqueous solutions of amino acids is different from that of anions, and allows for a novel and Consistent molecular description of the effect of the cation on the solubility based on specific interactions of the cations with the negatively charged moieties of the biomolecules.
keywords
MOLECULAR-DYNAMICS SIMULATION; HYDROPHOBIC IONIC LIQUIDS; HOFMEISTER SERIES; L-LEUCINE; CARBOXYLIC-ACIDS; HORSERADISH-PEROXIDASE; MUTUAL SOLUBILITIES; PROTEIN DENATURANTS; WATER COORDINATION; SELF-ASSOCIATION
subject category
Chemistry
authors
Tome, LIN; Pinho, SP; Jorge, M; Gomes, JRB; Coutinho, JAP
our authors
José R. B. Gomes
Principal Researcher
Luciana Isabel Nabais Tomé
Post-doc FellowshipGroups
G4 - Renewable Materials and Circular Economy
G6 - Virtual Materials and Artificial Intelligence
acknowledgements
The authors thank financial support from Fundacao para a Ciencia e a Tecnologia for Programa Ciencia 2007 and the postdoctoral grant SFRH/BPD/44926/2008 awarded to L.I.N.T. This work is partially supported by projects PEst-C/EQB/LA0020/2011 and PEst-C/CTM/LA0011/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia.