abstract
The interactions established by mono and polyvalent cations in natural media have important implications on the structure formation, function and physico-chemical behavior of biomolecules, playing therefore a critical role in biochemical processes. In order to further elucidate the molecular phenomena behind the cation specific effects in biological environments, and clarify the influence of the charge of the ions, solubility measurements and 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 comprising mono-, di- and trivalent cations (LiCl, Li2SO4, K2SO4, CaCl2, AlCl3 and Al-2(SO4)(3)). The evidence gathered indicates that the mechanism by which (salting-in inducing) polyvalent cations affect the solubility of amino acids in aqueous solutions is different from that of monovalent cations. A consistent and refined molecular description of the effect of the cation on the solubility of amino acids based on specific interactions of the cations with the negatively charged moieties of the biomolecules is here proposed.
keywords
MOLECULAR-DYNAMICS METHOD; METAL-IONS LI+; HOFMEISTER SERIES; ALUMINUM(III) INTERACTIONS; ELECTROLYTE SOLUTIONS; MAGNETIC-RESONANCE; WATER COORDINATION; NMR-SPECTROSCOPY; L-TYROSINE; L-CYSTINE
subject category
Chemistry
authors
Tome, LIN; Sousa, CSR; Gomes, JRB; Ferreira, O; Coutinho, JAP; Pinho, SP
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
Projects
acknowledgements
This work was financed by national funding from FCT (Fundacao para a Ciencia e a Tecnologia) through the project PTDC/QUI-QUI/121520/2010, by FEDER funding through program COMPETE, and by national funding through FCT, in the ambit of project CICECO-FCOMP-01-0124-FEDER-037271 (Pest-C/CTM/LA0011/2013), LSRE/LCM (project PEST-C/EQB/LA0020/2013) and project NORTE-07-0162-FEDER-000050. We also acknowledge FCT for the postdoctoral grant SFRH/BPD/44926/2008 to LINT. JRBG acknowledges FCT for the 2012 FCT Investigator Program position.