Complexation process of amylose under different concentrations of linoleic acid using molecular dynamics simulation

Abstract

Owing to its importance in food and pharmaceutical applications, complexation of amylose with amphiphilic molecules has been experimentally and theoretically investigated. Most theoretical studies have involved only a single amphiphilic molecule as the guest. In the present work, Molecular Dynamics (MD) is utilized to study this complexation process when more than one amphiphilic molecule (linoleic acid) is complexing with an amylose fragment. Results showed that the amylose fragment complexed with linoleic acid to form a V-type structure, and more glucose residues participated when the number of linoleic acid molecules increased. Intra-molecular hydrogen bonds are the main interactions that stabilize the formation of the amylose helical structure. The preferred location of the linoleic acids molecules was in the central region of the amylose fragment, which induced a larger fluctuation of the two terminal regions of the complex. Alike when a single linoleic acid molecule is considered, the aliphatic tails of the linoleic acid molecules complexed with the hydrophobic cavity of the amylose fragment and the carboxyl heads were exposed to the polar water molecules.

Keywords: Complexation; Linoleic acid concentration; MD simulation; Molecular conformation; Molecular orientation.