Apparent Molar Volumes of Proline-Leucine Dipeptide in NaCl Aqueous Solutions at 318.15 K

Density measurements of pseudo-binary solutions of proline-leucine dipeptide in aqueous NaCl solutions with molality ranging from 0 to 1 mol-kg^–1 have been performed at 318.15 K. Apparent molar volumes, V_{, 2}, of proline-leucine were calculated from the measured data. Limiting partial molar volumes, V₂, and limiting partial molar volumes of transfer from water to aqueous NaCl solutions, _tr V₂, were derived and interpreted in terms of ion-dipeptide interactions and changes in the characteristics of the hydration shell around the biomolecules as well.