Abstract
A method for calculating the isopotential partial specific volumes of proteins in concentrated salt, sugar, and amino acid solutions has been developed. It is based on the finding that the preferential hydration of the protein in these solutions is relatively independent of the concentration of the additive and is proportional to the specific surface area of the proteins, i.e., to the ratio of the total accessible surface area to molecular weight. Agreement between the calculated and experimental values was satisfactory, indicating the reliability of the proposed method. These calculations show that the isopotential partial specific volume increases greatly with the concentration of the additive, in particular in the case of Na2SO4, (NH4)2SO4, and sucrose, and for smaller proteins.
