Versatility of self-assembling A6K peptide nanomembranes under thermal variation: a molecular dynamics analysis across the 300-400 K range

Abstract

This study explores the influence of temperature on nanomembranes composed of A6K amphiphilic peptides in aqueous solution, employing Classical Molecular Dynamics simulations. These nanomembranes hold significant potential for applications in fields like controlled drug delivery, tissue engineering, and organic supercapacitors. Two distinct systems were analyzed: (Model-A) with a +1e charge localized on the nonpolar Alanine residue, and (Model-B) with the same charge distributed across the polar Lysine residue. The thermal effects were investigated through two approaches: simulations conducted at fixed temperatures ranging from 300 K to 400 K in 10 K increments, and simulations involving continuous temperature variations from 300 K to 400 K in 5 K steps every 2 ns. The structural analyses encompassed mass density profiles, hydrogen bonding interactions, and Ramachandran plots, while the interaction energies were examined using Coulomb and Lennard-Jones potentials. The results revealed that in both models, the total number of hydrogen bonds remained nearly constant across the analyzed temperature range. However, the lifetime and the energy required to disrupt these bonds progressively decreased with increasing temperature. Model-B exhibited enhanced structural flexibility and a lower number of hydrogen bonds, indicating greater suitability for molecule insertion, such as drug delivery applications, due to the reduced energy cost associated with penetration into the nanomembrane. This study advances the understanding of temperature effects on peptide-based nanomembranes, addressing a notable gap in the scientific literature and opening new ways for the development of innovative applications harnessing their dynamic and structural characteristics.