Figure 5.

Interaction between amino acids, dipeptides, or tripeptides in solution. Comparison of osmotic coefficients of amino acid, dipeptide, and tripeptide solutions between experiment and simulations. Na⁺ counterion is used for charged amino acids. Larger values mean less attraction between amino acids, dipeptides, and tripeptides. The increasing size of the symbol indicates 0.5 (0.3 for tripeptides), 1, and 2 molar (simulation) and molal (experiment) concentration of solutions, respectively. Experimental values at molality scale are shown at 0.5 (except tripeptide 0.3 m), 1, and 2 m. Tripeptide points are shown with the diamond symbol. Simulation errors are ≈0.02, given as the standard deviation.