1
|
Mistry SN, Shonberg J, Draper-Joyce CJ, Herenbrink CK, Michino M, Shi L, Christopoulos A, Capuano B, Scammells PJ, Lane JR. Discovery of a Novel Class of Negative Allosteric Modulator of the Dopamine D2 Receptor Through Fragmentation of a Bitopic Ligand. J Med Chem 2015; 58:6819-43. [PMID: 26258690 PMCID: PMC10823399 DOI: 10.1021/acs.jmedchem.5b00585] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recently, we have demonstrated that N-((trans)-4-(2-(7-cyano-3,4-dihydroisoquinolin-2(1H)-yl)ethyl)cyclohexyl)-1H-indole-2-carboxamide (SB269652) (1) adopts a bitopic pose at one protomer of a dopamine D2 receptor (D2R) dimer to negatively modulate the binding of dopamine at the other protomer. The 1H-indole-2-carboxamide moiety of 1 extends into a secondary pocket between the extracellular ends of TM2 and TM7 within the D2R protomer. To target this putative allosteric site, we generated and characterized fragments that include and extend from the 1H-indole-2-carboxamide moiety of 1. N-Isopropyl-1H-indole-2-carboxamide (3) displayed allosteric pharmacology and sensitivity to mutations of the same residues at the top of TM2 as was observed for 1. Using 3 as an "allosteric lead", we designed and synthesized an extensive fragment library to generate novel SAR and identify N-butyl-1H-indole-2-carboxamide (11d), which displayed both increased negative cooperativity and affinity for the D2R. These data illustrate that fragmentation of extended compounds can expose fragments with purely allosteric pharmacology.
Collapse
Affiliation(s)
- Shailesh N. Mistry
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Jeremy Shonberg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Christopher J. Draper-Joyce
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Carmen Klein Herenbrink
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Mayako Michino
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Unit, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, NY, USA
- Institute for Computational Biomedicine, Weill Medical College of Cornell University, New York, NY, USA
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Ben Capuano
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Peter J. Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - J. Robert Lane
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| |
Collapse
|