gmx_RRCS: A Precision Tool for Detecting Subtle Conformational Dynamics in Molecular Simulations.

Area of Science:

• Computational Biology
• Structural Biology
• Drug Design

Background:

• Understanding biomolecular conformational changes is vital for biological function and drug discovery.
• Existing methods like RMSD and RMSF struggle to detect subtle dynamics, such as hydrophobic packing.

Purpose of the Study:

• Introduce gmx_RRCS, a novel tool for detecting subtle conformational dynamics in molecular dynamics (MD) simulations.
• Quantify residue-residue interaction strengths to systematically analyze conformational changes.

Main Methods:

• Developed gmx_RRCS, a precision tool analyzing residue-residue contact score (RRCS).
• Applied gmx_RRCS to systems including peptide-receptor interactions (GLP-1R), enzyme dynamics (PI3Kα), and nucleic acid-ligand binding (ochratoxin A, norfloxacin).
• Validated the tool across over 150 simulation trajectories (40,000 ns, 20 systems).

Main Results:

• gmx_RRCS successfully quantified interactions in peptide 20/GLP-1R binding, identifying key residues.
• Revealed distinct conformational states in PI3Kα hotspot residues, including sidechain reorientations and salt bridge dynamics.
• Differentiated binding mechanisms of ochratoxin A and norfloxacin to nucleic acids by identifying unique interaction patterns.

Conclusions:

• gmx_RRCS enhances the understanding of protein conformational dynamics.
• The tool facilitates more effective rational drug design by providing detailed interaction insights.
• gmx_RRCS is freely available, promoting wider adoption in structural and molecular biology research.