Enthalpic pair interaction coefficient between zwitterions of L-alpha-amino acids and urea molecule as a hydrophobicity parameter of amino acid side chains.
Dissolution enthalpies of L-alpha-proline, L-alpha-tyrosine, L-alpha-tryptophan, L-alpha-histidyne, L-alpha-arginine, L-alpha-lysine, L-aspartic acid, and L-alpha-glutamic acid in aqueous solutions of urea have been measured by calorimetry at a temperature of 298.15 K. The values of dissolution enthalpy were used to determine enthalpic heterogeneous pair interaction coefficients between the zwitterions of the natural amino acids and a molecule of urea in water solution. These coefficients were interpreted in terms of the hydrophobic or hydrophilic effects of the side chains of amino acids on their interactions with a polar molecule of urea in water.
Palecz
Bartlomiej
B
Department of Physical Chemistry, University of Lodz, 90-236 Lodz, Pomorska 165, Poland. paleczb@uni.lodz.pl
D000596:Amino Acids / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D012996:Solutions; D013237:Stereoisomerism; D013816:Thermodynamics; D014508:Urea / Q000737:chemistry*
D000596:Amino Acids; D012996:Solutions; D014508:Urea