Hydration of amino acids: An investigation using density functional theory

Abstract

Abstract Herein, we have investigated the effect of hydration of seven amino acids (AAs) such as alanine, aspartic acid,cysteine, glutamine, lysine, methionine, and phenylalanine with different number of water molecules using density functional theory. Among the hydrophobic AAs, cysteine has the highest interaction with water whereas in hydrophilic AAs, aspartic acid has the highest interaction with water. With the increase in number of water molecules, it is noted that alanine forms the most stable complex with water and methionine+water complex has least stability.In addition, we have calculated the chemical descriptors like chemical potential, electronegativity, hardness, softness, electrophilicity index of AAs to validate their interaction with water molecules. Interestingly, the gas phase interaction energy results match with the trend of electrophilicity index valuesof AAs.