Improvement of the reference interaction site model theory for calculating the partial molar volume of amino acids and polypeptides

We propose a simple, efficient bridge correction of the one-dimensional reference interaction site model (1D-RISM) theory. By combining the modified RISM method with the Kirkwood–Buff theory, the partial molar volume (PMV) is calculated for the 20 amino acids and for oligopeptides of glutamic acids in extended and α-helix conformations. The bridge correction drastically improves agreement between the calculated values and the experimental data.