Partial molar adiabatic compressibilities of transfer of some amino acids from water to aqueous lactose solutions at different temperatures

Apparent molar adiabatic compressibilities (K(Phi, s)) of glycine, L-alanine. L-valine, and L-leucine have been determined in aqueous and mixed aqueous solutions of lactose (2 to 6 mass%) at T = (293.15,298.15,30315, and 308.15) K. From these data partial molar adiabatic compressibilities at infinite dilution (K(Phi, s)(0)) have been evaluated to calculate corresponding transfer function. The transfer partial molar adiabatic compressibilities at infinite dilution (Delta K(Phi, s)(0)) are found to be positive. The decrease in the magnitude of transfer partial molar adiabatic compressibilities from glycine to L-leucine indicates the dominance of hydrophobic-hydrophobic interactions between the increasing side chains of amino acids. Also, the contributions of NH(3)(+)COO(-) , and CH(2) groups have been calculated by the linear correlation of K(Phi,) (0)(s) with number of carbon atoms in the alkyl chain of amino acids. (C) 2011 Elsevier B.V. All rights reserved.