Viscosities of l-Histidine/l-Glutamic Acid/l-Tryptophan/Glycylglycine + 2 M Aqueous KCl/KNO3 Solutions at T = (298.15 to 323.15) K

Abstract

Viscosity values of l-histidine/l-glutamic acid/l-tryptophan/glycylglycine + 2 M aqueous KCl/KNO 3 solutions have been determined experimentally as a function of molal concentration of amino acid/peptide at different temperatures: (298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K. Using the viscosity values of the solvent and solution, the relative viscosity, specific viscosity, and viscosity B-coefficient values have been computed. The trends of the variation of experimental and computed parameters with the solute concentration and temperature have been interpreted in terms of zwitterions-ions, zwitterions-water dipoles, ions-water dipoles, and ions-ions interactions operative in the systems.

Development of Thermophysical Property Models for Aqueous Amino Acid Solutions

“…Accurate measurements of density and heat capacity for amino acid aqueous solutions were made, mainly by the research group of Hakin [17][18][19][20][21][22][23][24][25][26][27]. The viscosity of aqueous amino acid solutions was measured by various research groups [21,[28][29][30][31][32][33][34][35][36][37][38][39][40]. As far as the authors are aware, reliable data for the thermal conductivity of aqueous amino acid solutions have not been measured and reported.…”

Viscometric Studies of Some Amino Acids/Peptides in Aqueous K<sub>2</sub>SO<sub>4</sub>/KNO<sub>3</sub> Solutions at Different Temperatures (298.15 - 323.15 K)

“…Electrolytes remain estimated to affect water structure, as well as the significance of involvement after structural variations of the solvent to the thermodynamic properties of aqueous solutions of biological molecules takes every so often strained. Amino acids and peptides have been taken up as model compounds for studying the interactions of protein molecules in solutions by a number of researchers [1]- [7]. Amino acids and their derivatives are also known as compensatory (or compatible) solutes in stabilizing proteins and enhancing enzyme activity [8] [9] [10].…”

Viscosities of l-Phenylalanine, l-Leucine, l-Glutamic Acid, or l-Proline + 2.0 mol·dm−3 Aqueous NaCl or 2.0 mol·dm−3 Aqueous NaNO3 Solutions at T = (298.15 to 328.15) K

“…Viscosities of l -alanine, l -proline, l -valine, and l -leucine in 2.0 mol·dm −3 aqueous KCl and 2.0 mol·dm −3 aqueous KNO 3 , and l -histidine, l -glutamic acid, l -tryptophan, and glycylglycine in 2.0 mol·dm −3 aqueous KCl and 2.0 mol·dm −3 aqueous KNO 3 solutions, and l -leucine, l -asparagine, and glycylglycine in 1.5 mol·dm −3 aqueous NaCl, NaNO 3 , and KNO 3 solutions and in 1.5 mol·dm −3 KCl, 1.0 mol·dm −3 KNO 3 , and 0.5 mol·dm −3 K 2 SO 4 have been measured for several molal concentrations of amino acids and peptides at different temperatures of (303.15, 308.15, 313.15, 318.15, and 323.15) K in our laboratory. The results have been discussed in terms of solute−solvent and solute−solute interactions.…”