Protein-ligand docking using hamiltonian replica exchange simulations with soft core potentials

Area of Science:

• Computational chemistry
• Molecular modeling
• Biophysics

Background:

• Molecular dynamics (MD) simulations in explicit solvent are powerful for studying receptor-ligand binding.
• Standard MD can get trapped in non-native binding geometries, hindering accurate complex discovery.
• Efficiently sampling diverse binding configurations remains a challenge.

Purpose of the Study:

• To develop and validate a Hamiltonian replica-exchange molecular dynamics (H-REMD) protocol.
• To enhance the sampling of potential ligand-receptor complexes.
• To accelerate the identification of native binding geometries.

Main Methods:

• A novel H-REMD protocol was designed by softening nonbonded ligand-receptor interactions across replicas.
• One reference replica maintained the original force field for accurate energy evaluation.
• The method was tested on two receptor-ligand systems and one protein-peptide complex.

Main Results:

• The H-REMD method successfully identified known binding geometries starting from incorrect initial docking poses.
• Compared to standard MD, H-REMD reached the native binding state significantly faster.
• The protocol demonstrated efficiency in exploring alternative binding sites.

Conclusions:

• H-REMD is an effective strategy for overcoming sampling limitations in molecular dynamics simulations.
• This approach accelerates the identification of correct ligand-receptor complex structures.
• The method holds potential for evaluating alternative binding modes and their relative affinities.