Why are MD simulated protein folding times wrong?

Area of Science:

• Computational biology
• Biophysics
• Molecular dynamics simulations

Background:

• Accurate simulation of protein folding is crucial for understanding biological function.
• Molecular dynamics (MD) simulations are a key tool for studying protein folding dynamics.

Purpose of the Study:

• To investigate the causes of significant deviations between simulated and experimental protein folding times.
• To assess the sensitivity of protein folding time predictions to simulation model parameters.

Main Methods:

• Utilized Markov State Models (MSM) to describe conformational dynamics of peptides and proteins.
• Analyzed the impact of varying simulation parameters, including forcefield and temperature, on folding times.
• Examined two specific peptide systems to illustrate observed deviations.

Main Results:

• Protein folding times simulated using MSMs are highly sensitive to model parameters.
• Modest variations in forcefield and temperature can lead to order-of-magnitude differences in folding times.
• Observed significant discrepancies between simulated and experimental folding rates for the studied peptides.

Conclusions:

• Simulated protein folding rates derived from molecular dynamics require careful interpretation due to parameter sensitivity.
• The choice of forcefield and temperature critically influences the accuracy of simulated folding times.
• Further refinement of simulation methodologies is needed to improve the reliability of folding time predictions.