Related Experiment Video
Updated: Feb 15, 2026

Environmental Modulations of the Number of Midbrain Dopamine Neurons in Adult Mice
Published on: January 20, 2015
The structural determinants of the bitopic binding mode of a negative allosteric modulator of the dopamine D2
Christopher J Draper-Joyce1, Mayako Michino2, Ravi Kumar Verma2
1Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 399 Royal Parade, Parkville, VIC 3052, Australia.
Abstract:
SB269652 is a negative allosteric modulator of the dopamine D2 receptor (D2R) yet possesses structural similarity to ligands with a competitive mode of interaction. In this study, we aimed to understand the ligand-receptor interactions that confer its allosteric action. We combined site-directed mutagenesis with molecular dynamics simulations using both SB269652 and derivatives from our previous structure activity studies. We identify residues within the conserved orthosteric binding site (OBS) and a secondary binding pocket (SBP) that determine affinity and cooperativity. Our results indicate that interaction with the SBP is a requirement for allosteric pharmacology, but that both competitive and allosteric derivatives of SB269652 can display sensitivity to the mutation of a glutamate residue (E952.65) within the SBP. Our findings provide the molecular basis for the differences in affinity between SB269652 derivatives, and reveal how changes to interactions made by the primary pharmacophore of SB269652 in the orthosteric pocket can confer changes in the interactions made by the secondary pharmacophore in the SBP. Our insights provide a structure-activity framework towards rational optimization of bitopic ligands for D2R with tailored competitive versus allosteric properties.
More Related Videos
10:19High-throughput Flow Cytometry Cell-based Assay to Detect Antibodies to N-Methyl-D-aspartate Receptor or Dopamine-2 Receptor in Human Serum
Published on: November 23, 2013
14:44Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Related Concept Videos
Cooperative Allosteric Transitions
Cooperative Allosteric Transitions
Ligand Binding and Linkage
Internal Receptors
Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists
Protein-Drug Binding: Determination Methods
Indirect methods involve isolating the bound drug from its free form in biological samples such as blood, serum, or plasma. These techniques aim to measure the percentage of drugs bound to proteins. Equilibrium dialysis is a commonly used method where the free drug concentration at equilibrium is measured by separating the bound...