The interactions between some N-acetyl-N′-methyl-l-α-amino acid amides and urea in water at 298.15K

The enthalpies of solution of some dipeptides in aqueous urea mixtures at T=298.15K

“…It is interesting to compare the results obtained with the values of the parameters of interactions between urea and amino acids [19] and N-acetyl-N 0 -methyl amino acid amides [3] in aqueous solutions. Figure 1 shows the dependence of enthalpic interaction coefficients of dipeptide-urea pairs, h DpepU , on the interaction coefficients of amino acid-urea pair, h AU [19], in water.…”

“…The values obtained for the enthalpic interaction coefficients of dipeptide-urea pairs, h DpepU , are listed also with the enthalpic interaction coefficients of N-acetyl-N 0 -methyl-L-a-amino acid amides [3] (figure 2). The correlation obtained indicates that the amino acid side substituents, both of dipeptides and the discussed amides, make similar contributions to the total effect of their interaction with urea, described by the enthalpic heterogeneous pair interaction coefficients.…”

“…Due to the variety of functional groups occurring in protein macromolecules and their complex structure, the results of their interactions in aqueous solution with other components are very difficult to interpret. Therefore many research centres carry out studies on the interactions of compounds whose molecular structure is characterised by the elements of protein structure such as methyl amides of natural amino acids [1][2][3][4], dipeptides [5][6][7], and tripeptides [8,9]. Our team has recently studied the interactions between the molecules of dipeptides, derivatives of glycin, and the molecules of urea.…”

“…Plot of the enthalpic interactions coefficients of dipeptide-urea pairs, h DpepU , against the interaction coefficients of N-acetyl-N 0 -methyl-L-a-amino acid amides-urea pairs, h AmU[3] in water.…”

Study of the interaction between ethanol and natural amino acids containing ionic side groups in water at T = 298.15 K

“…The complex structure of biomacromolecules poses difficulties in the interpretation of the processes, in which they participate. Therefore, simple model systems such as L-a-amino acids [1][2][3] or small peptides [4][5][6] are often used for such investigations. Moreover, every living organism contains a constant stock of free natural amino acids, which participate in life processes, interact with the components of intracellular and extracellular fluids.…”