Transfer Partial Molar Volumes of l-Alanine/l-Glutamine/Glycylglycine from Water to 0.512 mol·kg^–1 Aqueous KNO₃/K₂SO₄ Solutions at (298.15 to 323.15) K

Abstract

Densities of l-alanine/l-glutamine/glycylglycine + 0.512 mol·kg–1 aqueous K2SO4/KNO3 systems have been measured for several molal concentrations of amino acids/peptide at different temperatures from T = (298.15 to 323.15) K using a density and sound velocity meter (Anton Paar DSA, 5000 m). Using the density data the partial molar volumes (ϕ v 0) and transfer partial molar volumes (Δtrϕ v 0) have been calculated. The measured and calculated thermodynamic parameters have been discussed in terms of zwitterion–ion, zwitterion–water dipole, ion–water dipole, and ion–ion interactions operative in the systems.

Effect of 1-Ethyl-3-methylimidazolium Bromide Ionic Liquid on the Volumetric Behavior of Some Aqueous l-Amino Acids Solutions

“…The denaturation of a protein in different aqueous solutions containing salts is an important behavior of biological molecules and has been the subject of extensive investigation. − However, the complex configurational and conformational aspects of protein structure in aqueous solution, make it very difficult to directly interpret various biological processes with salts. In recent years, it is recognized that the physicochemical investigations of aqueous solutions containing amino acids − or small peptides − are of considerable importance and will be helpful in the fundamental understanding of denaturation and other complicated biological processes. Among these technologies, volumetric studies − ,− can provide some unique information in terms of ligand-binding properties, as well as the folding/unfolding character and conformational stability of a globular protein. , …”

“…In recent years, it is recognized that the physicochemical investigations of aqueous solutions containing amino acids − or small peptides − are of considerable importance and will be helpful in the fundamental understanding of denaturation and other complicated biological processes. Among these technologies, volumetric studies − ,− can provide some unique information in terms of ligand-binding properties, as well as the folding/unfolding character and conformational stability of a globular protein. , …”

Solvation Properties of Branched-Chain Amino Acids in Aqueous Solutions of 1-Dodecyl-3-methylimidazolium Bromide at Different Temperatures: Volumetric and Acoustic Measurements

“…In recent times, it has become obvious that thermodynamic analyses of aqueous solutions containing amino acids and small peptides seem essential for understanding conformational changes and other biological systems processes. Among these technologies, the volumetric investigations − are helpful in understanding the ligand binding properties and provide some unique information in terms of folding/unfolding nature and structural stability of a helical protein. , The thermodynamic properties of mixtures, including amino acids, and the first production of ILs in aqueous solutions at varying temperatures have been documented in several recent articles. − In prior writings, − we have stated that short-chain ILs have been shown to affect the solubility of amino acids and dipeptides. We raised the alkyl chain length from C6 to C12 to boost the solubility of branched-chain acetyl substituted amino acids ( N -acetyl l -glycine/ N -acetyl l -leucine).…”

Densities and Speeds of Sound for Sucrose in Aqueous Solutions of Ammonium Phosphate Salts at Different Temperatures through Density and Speed of Sound Measurements

“…On the other hand, DAP is also a water-soluble salt. There are extensive studies regarding the interactions between saccharides and amino acids − and on the thermodynamics of amino acids + water + saccharides − and of saccharides + salt–water-mixed solvents. − There is wide research on the studies of densities and speeds of sound for aqueous solutions of sucrose with different additives ,,, but till now, no comparative studies have been carried out on the acoustic and volumetric properties of sucrose with aqueous ADP and DAP. So, we prearranged to have volumetric and acoustic (compressibility) studies on sucrose with aqueous ADP and DAP solutions.…”