Homology Model and Docking-Based Virtual Screening for Ligands of the σ1 Receptor

This study presents for the first time the 3D model of the sigma(1) receptor protein as obtained from homology modeling techniques, shows the applicability of this structure to docking-based virtual screening, defines a computational strategy to optimize the results based on a combination of 3D pharmacophore-based docking and MM/PBSA free energy of binding scoring, and provides evidence that these in silico models and recipes are powerful tools on which virtual screening of new sigma(1) ligands can be based. In particular, the validation of the applicability of docking-based virtual screening to homology models is of utmost importance, since no crystal structure is available to date for the sigma(1) receptor, and this missing information still constitutes a major hurdle for a rational ligand design for this important protein target.