The Universal 3D QSAR Model for Dopamine D2 Receptor Antagonists.

Agata Zięba,Agnieszka A Kaczor,Antti Poso,Damian Bartuzi,Dariusz Matosiuk,Justyna Żuk

doi:10.3390/ijms20184555

Abstract

In order to search for novel antipsychotics acting through the D2 receptor, it is necessary to know the structure–activity relationships for dopamine D2 receptor antagonists. In this context, we constructed the universal three-dimensional quantitative structure–activity relationship (3D- QSAR) model for competitive dopamine D2 receptor antagonists. We took 176 compounds from chemically different groups characterized by the half maximal inhibitory concentration (IC50)from the CHEMBL database and docked them to the X-ray structure of the human D2 receptor in the inactive state. Selected docking poses were applied for Comparative Molecular Field Analysis (CoMFA) alignment. The obtained CoMFA model is characterized by a cross-validated coefficient Q2 of 0.76 with an optimal component of 5, R2 of 0.92, and an F value of 338.9. The steric and electrostatic field contributions are 67.4% and 32.6%, respectively. The statistics obtained prove that the CoMFA model is significant. Next, the IC50 of the 16 compounds from the test set was predicted with R2 of 0.95. Finally, a progressive scrambling test was carried out for additional validation. The CoMFA fields were mapped onto the dopamine D2 receptor binding site, which enabled a discussion of the structure–activity relationship based on ligand–receptor interactions. In particular, it was found that one of the desired steric interactions covers the area of a putative common allosteric pocket suggested for some other G protein-coupled receptors (GPCRs), which would suggest that some of the known dopamine receptor antagonists are bitopic in their essence. The CoMFA model can be applied to predict the potential activity of novel dopamine D2 receptor antagonists.

Highlights

The dopamine D2 receptor is the main molecular target of all antipsychotics currently available on the pharmaceutical market
In order to search for novel antipsychotics acting through the D2 receptor, it is necessary to know the structure–activity relationships for dopamine D2 receptor antagonists
The Comparative Molecular Field Analysis (CoMFA) fields were mapped onto the dopamine D2 receptor binding site, which enabled a discussion of the structure–activity relationship based on ligand–receptor interactions

Summary

Introduction

The dopamine D2 receptor is the main molecular target of all antipsychotics currently available on the pharmaceutical market. In order to search for novel antipsychotics, it is necessary to investigate structure–activity relationships for dopamine D2 receptor ligands. Three-dimensional quantitative structure–activity relationship (3D-QSAR) methods are crucial for drug discovery and ligand-based molecular modeling. These techniques are useful if the 3D structure of a molecular target is not available. 3D-QSAR techniques are applied to determine the relationship between the molecular properties and observed pharmacological activities of a group of congeneric compounds [4,5]. A widely used 3D-QSAR approach is Comparative Molecular Field Analysis (CoMFA), which uses statistical methods to correlate steric and electrostatic properties of a series of molecules with their pharmacological activities

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