Simulating Protein Fold Switching by Replica Exchange with Tunneling

Area of Science:

• Protein dynamics and biophysics
• Computational biology and structural bioinformatics
• Molecular simulation and modeling

Background:

• Emerging evidence indicates protein amino acid sequences encode multiple functional conformations.
• These conformations exist within a complex folding landscape influenced by environmental factors and molecular interactions.
• Understanding these alternative folds is crucial for protein function, folding, and association.

Purpose of the Study:

• To develop an efficient computational method for simulating transitions between distinct protein folds.
• To investigate the multifunnel folding and association landscape of proteins and protein aggregates.
• To validate the proposed simulation technique across various protein systems.

Main Methods:

• Introduction of replica exchange with tunneling (RET) for enhanced conformational sampling.
• Application of RET to simulate switching between distinct protein folds.
• Validation through simulations of a designed peptide and mutants of protein G domains.

Main Results:

• Demonstrated the correctness and efficiency of the replica exchange with tunneling method.
• Successfully simulated transitions between multiple distinct folds for tested protein systems.
• Showcased the method's applicability to systems ranging from small peptides to larger protein domains.

Conclusions:

• Replica exchange with tunneling is an effective approach for simulating protein fold switching.
• The method facilitates the exploration of complex protein folding landscapes and conformational ensembles.
• This computational tool aids in understanding the functional versatility encoded within protein sequences.