Differential Virtual Screening (DVS) with Active and Inactive Molecular Models for Finding and Profiling GPCR...

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• The neurotensin NT1 receptor is a class-A G protein-coupled receptor (GPCR).
• Constitutively activating mutations (CAMs) can provide insights into receptor function and drug discovery.
• Understanding GPCR conformational states is crucial for developing selective ligands.

Purpose of the Study:

• To investigate the functional consequences of a CAM (V308E) in the neurotensin NT1 receptor.
• To develop and validate active and inactive molecular models for class-A GPCRs using molecular dynamics (MD) and homology modeling.
• To apply differential virtual screening (DVS) for identifying novel agonists and antagonists for the cholecystokinin CCK1 receptor.

Main Methods:

• Molecular dynamics (MD) simulations of wild-type and CAM NT1 receptors.
• Homology modeling of the cholecystokinin CCK1 receptor using active and inactive templates.
• Virtual screening of a large compound library against CCK1 receptor models.
• Differential virtual screening (DVS) analysis to predict agonists and antagonists.
• In vitro cellular assays to validate predicted CCK1 receptor ligands.

Main Results:

• The CAM NT1-V308E exhibited high spontaneous activity, distinct from the wild-type receptor, as shown by MD simulations.
• Homology models of active and inactive CCK1 receptors were successfully generated.
• DVS identified 250 predicted agonists and 250 predicted antagonists for the CCK1 receptor.
• Experimental validation showed an excellent correlation between DVS predictions and biological assay results.

Conclusions:

• The study successfully generated and validated active and inactive molecular models for class-A GPCRs.
• DVS using these models is an effective strategy for identifying GPCR agonists and antagonists.
• This approach holds promise for the discovery of ligands, particularly for orphan GPCRs.