Hydrophobic solvation in aqueous trifluoroethanol solution

Area of Science:

• Biochemistry
• Molecular Biology
• Computational Chemistry

Background:

• De novo peptide design aims to create novel protein structures.
• Understanding peptide folding in solution is crucial for biomolecular engineering.
• Trifluoroethanol (TFE) is known to promote secondary structure formation in peptides.

Purpose of the Study:

• To investigate the mechanism by which TFE induces helix formation in a designed peptide.
• To identify specific interactions between TFE and peptide residues.
• To provide a molecular basis for TFE's helix-enhancing effects.

Main Methods:

• Titration of a de novo designed peptide with TFE in aqueous solution.
• Molecular dynamics simulations of the peptide in TFE/water mixtures.
• Analysis of solvent-peptide interactions and conformational changes.

Main Results:

• Complete helix formation was observed at 30% TFE concentration.
• Molecular simulations revealed preferential binding of TFE to hydrophobic side chains.
• TFE molecules formed a stabilizing shell around the peptide.

Conclusions:

• TFE effectively stabilizes peptide helices by interacting with hydrophobic residues.
• The observed helix formation is driven by the stabilization of hydrophobic collapse.
• This study provides insights into peptide structure stabilization using organic co-solvents.