Solute Tempered Adiabatic Free Energy Dynamics for Enhancing Conformational Space Sampling

Area of Science:

• Computational chemistry
• Molecular dynamics simulations
• Biophysics

Background:

• Enhanced sampling methods accelerate molecular dynamics (MD) simulations by improving conformational sampling.
• Collective variable (CV)-based methods and generalized ensemble techniques like Temperature-Accelerated Molecular Dynamics (TAMD)/driven-Adiabatic Free Energy Dynamics (d-AFED) and Replica Exchange with Solute Tempering (REST2) are crucial for studying complex systems.
• Large biomolecular systems often require combined strategies due to significant entropic barriers.

Purpose of the Study:

• To introduce and validate a novel enhanced sampling method, Solute Tempered d-AFED (STed-AFED).
• To combine the strengths of d-AFED/TAMD and REST2 for superior conformational sampling.
• To demonstrate the method's efficacy on small peptides and proteins.

Main Methods:

• Implementation of STed-AFED by integrating d-AFED/TAMD and REST2 within the OpenMM-UFEDMM interface.
• Application of the STed-AFED method to explore the conformational landscapes of chignolin, Trp-cage, and villin.
• Utilizing extended variables thermostated at high temperatures and scaled solute-solvent interactions for enhanced exploration.

Main Results:

• The STed-AFED method effectively combines CV-based enhanced sampling with global tempering.
• Demonstrated improved conformational sampling efficiency for small peptides and proteins.
• Successfully mapped complex conformational landscapes previously challenging for standard methods.

Conclusions:

• STed-AFED represents a significant advancement in enhanced sampling techniques for molecular dynamics.
• The combined approach overcomes limitations of individual methods, particularly for large and complex biomolecular systems.
• This method provides a powerful tool for detailed conformational analysis in computational biophysics.