The partial molar heat capacity and volume of the peptide backbone group of proteins in aqueous solution

Abstract

The partial molar heat capacities have been determined for the series of peptides alanyl(glycyl) xglycine, x=1–3, and for the compounds N-acetylglycinamide and N-acetyl glycylglycinamide in aqueous solution over the temperature range 10–100°C using high sensitivity scanning microcalorimetry. The partial molar volumes for these compounds have also been determined over the temperature range from 10 to 90°C using a scanning densimetric method. The results were used to derive the partial molar heat capacities and volumes of the glycyl group at temperatures in the range 10–100°C. The results obtained are critically compared with literature results derived using heat capacity and volume data for some oligoglycines.