QUANTUM CHEMICAL SIMULATION OF THE INTERACTION BETWEEN CARNOSINE AND ANSERINE DIPEPTIDES AND THE SODIUM DODECYL SULFATE DIMER AS AN ANIONIC MICELLE FRAGMENT

Dipeptide complexes of β-alanyl-histidine (carnosine) and β-alanyl-1-methyl-histidine (anserine) with the sodium dodecyl sulfate dimer (SDS)2 are studied by the DFT/B97D quantum chemical method using the 6-311++G(3d,3p) basis set. The most stable configurations of peptide complexes in cationic and zwitterionic forms with the (SDS)2 dimer are found. The changes in peptide structures and energies as a result of the complexation are analyzed. It is shown that both ionic forms of carnosine can participate in the reaction with the SDS dimer in aqueous solution. The influence of the methyl substituent in the imidazole ring of anserine is noticeably manifested in the lengths of H-bonds formed by the $$\text{NH}^+_3$$ group of the peptide with SDS due to high steric barriers encountered by the substituted peptide as it adjusts to the dimer structure. The complexation energies have close values for anserine and carnosine cations.