Folding thermodynamics of three beta-sheet peptides: a model study

Area of Science:

• Biophysics
• Computational Biology
• Protein Folding

Background:

• Understanding peptide and protein folding is crucial for molecular biology and drug design.
• Beta-hairpins and beta-sheets are fundamental protein secondary structures with significant biological roles.

Purpose of the Study:

• To investigate the folding thermodynamics of a beta-hairpin and two three-stranded beta-sheet peptides.
• To validate a simplified sequence-based all-atom model against experimental data.
• To analyze the dependence of apparent native population on different observables.

Main Methods:

• Utilized a simplified sequence-based all-atom model for peptide folding simulations.
• Focused on folding driven by backbone hydrogen bonding and hydrophobic attraction.
• Compared simulation results with experimental data for native populations.

Main Results:

• Achieved good agreement between simulated native populations and experimental data for three peptide sequences.
• Demonstrated that the apparent native population is observable-dependent.
• Observed differing results when analyzing hydrophobicity energy versus the number of native hydrogen bonds.

Conclusions:

• The simplified all-atom model effectively captures the folding thermodynamics of beta-hairpins and beta-sheets.
• The choice of observable significantly influences the determination of native population in peptide folding studies.
• The model's predictions for observable dependence align with experimental findings on beta-hairpins.