Thermodynamics of protein model compounds: An investigation of the apparent and partial molar heat capacities and volumes of aqueous solutions of alanyl and seryl side-chain containing cyclic dipeptides

Abstract

This study reports relative densities and heat capacity ratios for the cyclic dipeptides cyclo-glycylserine, cyclo-alanylglycine, cyclo-alanylserine and cyclo-serylserine in water over the temperature range 288.15 to 328.15 K. These values are used to calculate apparent molar volumes, V_2,ϕ, and heat capacities, C_{p2, ϕ}, which have been modelled to give partial molar volumes and heat capacities at infinite dilution. The partial molar properties at infinite dilution have been used to calculate the thermodynamic parameters for the amino acid side-chains of alanine and serine, which have been compared to values previously reported in the literature.