A MOLECULAR DYNAMICS SIMULATION STUDY OF CONFORMATIONAL CHANGES AND SOLVATION OF Aβ PEPTIDE IN TRIFLUOROETHANOL AND WATER

Abstract

Molecular dynamics (MD) simulations of amyloid beta peptide have been performed in aqueous solutions of trifluoroethanol with different concentrations. The amount of α-helical secondary structure increases when going from pure water to trifluoroethanol-rich solutions. The conformation obtained in 40% (v/v) trifluoroethanol solution is very similar to the experimental observations of beta peptide in sodium dodecyl sulfate micelle. In this solution, the peptide has two helical segments connected through a looped region. The C-terminal helix of beta peptide unfolds in pure water. The effect of trifluoroethanol on peptide's secondary structure has been explained using the properties calculated from MD trajectories.