Protein folding kinetics and thermodynamics from atomistic simulations

Area of Science:

• Computational biology
• Biophysics
• Molecular dynamics simulations

Background:

• Accurately determining protein folding kinetics and thermodynamics from all-atom molecular dynamics (MD) simulations is challenging due to simulations getting trapped in local minima.
• This necessitates the computation of multiple, potentially coupled, simulation trajectories, such as those used in replica exchange MD.

Purpose of the Study:

• To present a novel analysis tool for deducing faithful kinetics data from heterogeneous ensembles of simulation trajectories.
• To demonstrate the tool's capability in predicting protein folding and unfolding kinetics and thermodynamics without experimental data.

Main Methods:

• Development and application of a new analysis tool for heterogeneous molecular dynamics simulation ensembles.
• Utilizing the tool to analyze simulations of the decapeptide Chignolin.

Main Results:

• The tool successfully deduced faithful kinetics data from the simulation ensemble.
• Predicted folding and unfolding time constants for Chignolin: 1.0 ± 0.3 and 2.6 ± 0.4 microseconds, respectively.
• Derived the energetics of folding and calculated a realistic melting curve for Chignolin.

Conclusions:

• The new analysis tool enables accurate prediction of protein folding kinetics and thermodynamics from MD simulations.
• This method overcomes the challenge of simulation trapping in local minima, providing reliable biophysical data.
• The findings offer a pathway for advancing computational approaches in protein dynamics research.