Fluorinated Alcohol Biosolvents and α-Helix Peptide Secondary Structure: A Molecular Dynamics Study on the Solvent Concentration Effect

An upgraded GAFF2 force field has been used to simulate two fluorinated alcohols, TFE and HFIP, in aqueous solutions at several concentrations. The same force field has also been employed to simulate a 26-residue amphiphilic peptide in several cosolvent/water mixtures to verify and clarify its efficacy in stabilizing the secondary structure. The calculated thermodynamic and structural properties are in agreement with experimental findings. The force field allows a correct description of the secondary structure and affords an accurate characterization of the spatial organization of cosolvent molecules around the peptide.