The effect of chain length and side chains on the solubility of peptides in water from 278.15 K to 313.15 K: A case study in glycine homopeptides and dipeptides

•The effect of side chains and chain length on the solubility of peptides were explored.•The solvation free energies of studied peptides were calculated by Molecular Dynamic simulations.•The experimental solubility data are well correlated using the modified Apelblat model. The thermodynamic properties of peptides are significant in terms of the crystallization conditions of biomaterials. In this work, we seek to understand and explain the effect of side chains and chain length on the solubility of peptides. The amino acid residues of dipeptides investigated here were chosen based on their difference in side chain properties. The modified Apelblat equation was used to correlate the relationship between the solubility in water and temperature. In order to explore solute–solvent interactions, the solvation free energies of these peptides were calculated by Molecular Dynamic simulations. This work gives an indication of the effects of side chains and chain length on the solubility of amino acids and peptides in water under different temperatures, which not only provides the thermodynamic data for peptides, but is also critical in the prediction of peptide solubility using Statistical Associating Fluid Theory (SAFT).