Computational Analysis of Residue-Specific Binding Free Energies of Androgen Receptor to Ligands

Area of Science:

• Molecular pharmacology and computational chemistry.

Background:

• The androgen receptor (AR) is a critical therapeutic target for diseases including prostate cancer, hypogonadism, and muscle wasting.
• Understanding AR-ligand interactions is essential for developing effective treatments.

Purpose of the Study:

• To quantitatively analyze the binding mechanisms between the AR ligand-binding domain (LBD) and fifteen different ligands.
• To identify hotspot residues within the AR LBD that significantly contribute to ligand binding.
• To provide insights for the rational design of novel AR inhibitors.

Main Methods:

• Employed molecular dynamics simulations.
• Utilized the alanine-scanning-interaction-entropy (ASIE) method to calculate quantitative free energy contributions of pocket residues.
• Analyzed complex structures of the AR LBD with fifteen ligands.

Main Results:

• Quantitatively identified hotspot residues within the AR LBD.
• Found that these hotspot residues are predominantly hydrophobic.
• Demonstrated that the primary interactions between hotspot residues and ligands are van der Waals forces.
• Observed a good correlation between calculated total binding free energies and experimental binding data.

Conclusions:

• The study provides a quantitative analysis of the AR-ligand binding mechanism.
• Identified key hydrophobic residues and van der Waals interactions as critical for binding.
• Findings offer valuable insights for the design of future AR-targeted therapeutics.