Simulation of protein pulling dynamics on second time scale with boxed molecular dynamics

Area of Science:

• Computational chemistry
• Biophysics
• Protein dynamics

Background:

• Protein unfolding experiments, like atomic force microscopy, are crucial for understanding protein stability.
• Existing models, such as the kinetic two-state model, offer insights but have limitations in describing complex dynamics.
• Bridging atomistic detail with macroscopic experimental observations remains a challenge.

Purpose of the Study:

• To present Boxed Molecular Dynamics (BXD) as a method for kinetically describing protein pulling experiments.
• To establish a connection between atomistic protein structure and experimental results from protein unfolding studies.
• To demonstrate BXD's capability in modeling protein behavior over extended timescales.

Main Methods:

• Application of Boxed Molecular Dynamics (BXD) theory to analyze atomic force microscopy (AFM) protein unfolding experiments.
• Utilizing atomistic molecular dynamics simulations to derive BXD rate coefficients.
• Comparing BXD with the kinetic two-state model, highlighting differences in the number of states and data origin.

Main Results:

• BXD provides a kinetic description of protein pulling experiments, linking atomistic structure to experimental outcomes.
• The BXD model successfully describes the dependence of pulling force on pulling speed.
• BXD can accurately model protein unfolding experiments on timescales up to seconds, significantly longer than achievable with standard molecular dynamics.

Conclusions:

• Boxed Molecular Dynamics (BXD) offers a powerful framework for interpreting protein pulling experiments.
• BXD successfully bridges the gap between atomistic simulations and experimental observations in protein biophysics.
• The ability of BXD to model long-timescale dynamics opens new avenues for studying protein folding and stability.