Effect of Cosolvents and Ions on the Stability of Amino Acids, Peptides and Self-Assembled Peptide-Based Nanotubes

Abstract

There lies a major challenge in molecular biophysics towards understanding the various biophysical processes and molecular dynamics (MD) simulations have been an imperative tool in elucidating it at the molecular level. In many biological processes, water plays a crucial role as a basic solvent. The existence of biological water in the vicinity of biomolecules has profound implications and is particularly important for the structural and biological functions of the biomolecules. The functioning of these biomolecules emerges from the delicate balance between various interactions of biomolecules with the solvent environment. This balance can be modulated by the addition of ions and small molecules known as cosolvents. Molecular-level understanding of how these cosolvents affect the solvation shell near the biomolecules is important for understanding the factors affecting the stability of proteins. The presence of both hydrophilic and hydrophobic moieties in amino acids facilitates its use as surfactant-like peptides which can be designed into well-defined nanostructures. These peptide nanostructures have wide applications in the bio-medical field. The water molecules near these nanostructures behave differently from the structural and dynamic point of view. In this context, the present research work is focused on investigating the effect of cosolvents and ions on the solvation structure of amino acids and peptides which results in the stability/de-stability of proteins. Studies were done on water molecules present near the interface and bulk region of these biomolecules and peptide nanotubes.