Effects of l-α-amino acids side chains on their interparticle interactions with the dissociated potassium chloride in aqueous solutions

Abstract

Dissolution enthalpies of several natural amino acids (l-α-asparagine, l-α-glutamine, l-α-aspartic acid, l-α-glutamic acid, l-α-arginine, l-α-lysine and l-α-histidine) were measured in aqueous solutions of potassium chloride at T = 298.15 K. Based on the resulting data the standard dissolution enthalpy of amino acids in aqueous solutions of potassium chloride have been determined. The standard dissolution enthalpy values were subsequently used to calculate the heterogeneous enthalpic pair interaction coefficients (hA-KCl) between zwitterions of l-α-amino acids and dissociated potassium chloride in water. Interparticle interactions in system (amino acid + dissociated KCl + water) were interpreted in terms of the hydrophobic - hydrophilic effects of the side chains of the tested encoded amino acids.