The influence of structure of isomolecular dipeptides of α-L-alanyl-α-L-alanine and β-alanyl-β-alanine on their behavior in aqueous micellar solution of SDS

Abstract

Thermochemical characteristics of α-L-alanyl-α-L-alanine and β-alanyl-β-alanine interactions with SDS micelles at constant surfactant concentration and at various dipeptide contents have been determined. The anion micelles interaction with α-L-alanyl-α-L-alanine is accompanied by endothermic effects, the interaction with β-alanyl-β-alanine being of an exothermic character. The regularities observed may be attributed to different branching of the structure and hydrophobic properties of dipeptides. The tendencies of changing in the average size and ζ-potential of SDS micelles with different additives of dipeptides have also been examined. Additives of zwitterion dipeptides initiate the compensation of a negative charge and the decrease in size of micelles. In range of low concentration of β-alanyl-β-alanine the abrupt increasing of average micelle size is observed, while at high concentration, the micelle size diminishes.