Polyol–protein interactions. Thermodynamical evidence for a selective solvation of glycerol and hexitols by aqueous β-lactoglobulin

Abstract

Apparent specific heat capacities and volumes of the protein β-lactoglobulin have been determined under a variety of solute–solvent and solvent–cosolvent compositions. These quantities were derived from measurements of volumetric specific heats and densities with a flow microcalorimeter and flow densimeter. The effect of homologous polyols on the isothermal denaturation of the protein by urea at 25 °C was investigated. The results suggest that polyol binding on the protein is sensitive to structural effects, maximum discrimination being exerted in favor of glycerol and its doubles, the hexitols.