Heat capacity changes and partial molal heat capacities of some di- and tripeptides in water

Abstract

Integral enthalpies of solution of several dipeptides and tripeptides in water at low concentrations have been determined at 25 and 35°C. These data have been used to derive the changes in heat capacity on dissolution at infinite dilution ΔC^°_p at 30°C. Limiting partial molal heat capacities ΔC⁰_p2 have been determined by combining ΔC^°_p with C_p2 (heat capacity of pure solid peptides). Using the data on ω-amino acids and these peptides, the partial molal heat capacity of a peptide group -CONH- was semiquantitatively estimated.