Ligand with Two Modes of Interaction with the Dopamine D Receptor-An Induced-Fit Mechanism of Insurmountable Antagonism.

Richard Ågren, Hugo Zeberg, Tomasz Maciej Stępniewski, R Benjamin Free, Sean W Reilly, Robert R Luedtke, Peter Århem, Francisco Ciruela, David R Sibley, Robert H Mach, Jana Selent, Johanna Nilsson, Kristoffer Sahlholm

Journal: ACS chemical neuroscience 2021;11(19):3130-3143

PMID: 32865974

Free Full Text on American Chemical Society View on PubMed

Abstract

A solid understanding of the mechanisms governing ligand binding is crucial for rational design of therapeutics targeting the dopamine D receptor (DR). Here, we use G protein-coupled inward rectifier potassium (GIRK) channel activation in oocytes to measure the kinetics of DR antagonism by a series of aripiprazole analogues, as well as the recovery of dopamine (DA) responsivity upon washout. The aripiprazole analogues comprise an orthosteric and a secondary pharmacophore and differ by the length of the saturated carbon linker joining these two pharmacophores. Two compounds containing 3- and 5-carbon linkers allowed for a similar extent of recovery from antagonism in the presence of 1 or 100 μM DA (>25 and >90% of control, respectively), whereas recovery was less prominent (∼20%) upon washout of the 4-carbon linker compound, SV-III-130, both with 1 and 100 μM DA. Prolonging the coincubation time with SV-III-130 further diminished recovery. Curve-shift experiments were consistent with competition between SV-III-130 and DA. Two mutations in the secondary binding pocket (V91A and E95A) of DR decreased antagonistic potency and increased recovery from SV-III-130 antagonism, whereas a third mutation (L94A) only increased recovery. Our results suggest that the secondary binding pocket influences recovery from inhibition by the studied aripiprazole analogues. We propose a mechanism, supported by modeling, whereby SV-III-130 initially binds reversibly to the DR, after which the drug-receptor complex undergoes a slow transition to a second ligand-bound state, which is dependent on secondary binding pocket integrity and irreversible during the time frame of our experiments.

Address: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.; Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.; Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.; Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), 08003 Barcelona, Spain.; InterAx Biotech AG, PARK innovAARE, 5234 Villigen, Switzerland.; Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw 02-089, Poland.; Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke, Intramural Research Program, National Institutes of Health, Bethesda, Maryland 20892-3723, United States.; Department of Radiology, Division of Nuclear Medicine and Clinical Molecular Imaging, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, United States.; Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, Texas 76107, United States.; Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat 08907, Spain.; Neuropharmacology and Pain Group, Neuroscience Program, Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, L'Hospitalet de Llobregat 08907, Spain.; Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), 08003 Barcelona, Spain.; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.; Department of Neuroscience, Karolinska Institutet, Stockholm 171 77, Sweden.; Department of Integrative Medical Biology, Umeå University, Umeå 901 87, Sweden.; Wallenberg Centre for Molecular Medicine, Umeå University, Umeå 901 87, Sweden.

DOI: 10.1021/acschemneuro.0c00477

Link outs

Free resources

Full Text Sources:

Miscellaneous:

https://assays.cancer.gov/CPTAC-1774

MeSH Terms: Dopamine, Dopamine D2 Receptor Antagonists, GTP-Binding Proteins, Ligands, Receptors, Dopamine D2