Enthalpies of interaction of some N-acetyl amides of l-serine, l-threonine and l-hydroxyproline dissolved in N, N-dimethylformamide at 298.15 k

Abstract

The enthalpies of dilution of five dipeptides, namely, N-aeetyl- N '-methyl amides of l-serine, l-threonine and l-hydroxyproline, and JV-acetyl amides of l-threonine and l-hy-droxyproline dissolved in N, N-dirnethylformamide were measured calorimetrically at 298.15 K. From these, the enthalpic interaction coefficients were calculated. The pair-wise interaction coefficients of these dipeptides are compared with related amino acid derivatives with non-hydroxylated side chains. The influence of the hydroxyl group is discussed in terms of solute-solute-solvent interactions. The relevance of the results for biochemical systems is indicated.