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Ericson MD, Haslach EM, Schnell SM, Freeman KT, Xiang ZM, Portillo FP, Speth R, Litherland SA, Haskell-Luevano C. Discovery of Molecular Interactions of the Human Melanocortin-4 Receptor (hMC4R) Asp189 (D189) Amino Acid with the Endogenous G-Protein-Coupled Receptor (GPCR) Antagonist Agouti-Related Protein (AGRP) Provides Insights to AGRP's Inverse Agonist Pharmacology at the hMC4R. ACS Chem Neurosci 2021; 12:542-556. [PMID: 33470098 DOI: 10.1021/acschemneuro.0c00755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The melanocortin receptors (MCRs) are important for numerous biological pathways, including feeding behavior and energy homeostasis. In addition to endogenous peptide agonists, this receptor family has two naturally occurring endogenous antagonists, agouti and agouti-related protein (AGRP). At the melanocortin-4 receptor (MC4R), the AGRP ligand functions as an endogenous inverse agonist in the absence of agonist and as a competitive antagonist in the presence of agonist. At the melanocortin-3 receptor (MC3R), AGRP functions solely as a competitive antagonist in the presence of agonist. The molecular interactions that differentiate AGRP's inverse agonist activity at the MC4R have remained elusive until the findings reported herein. Upon the basis of homology molecular modeling approaches, we previously postulated a unique interaction between the D189 position of the hMC4R and Asn114 of AGRP. To further test this hypothesis, six D189 mutant hMC4Rs (D189A, D189E, D189N, D189Q, D189S, and D189K) were generated and pharmacologically characterized resulting in the discovery of differences in inverse agonist activity of AGRP and an 11 macrocyclic compound library. These data support the hypothesized interaction between the hMC4R D189 position and Asn114 residue of AGRP and define critical ligand-receptor molecular interactions responsible for the inverse agonist activity of AGRP at the hMC4R.
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Affiliation(s)
- Mark D. Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Erica M. Haslach
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Sathya M. Schnell
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Katie T. Freeman
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Zhimin M. Xiang
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Frederico P. Portillo
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Robert Speth
- College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida 33328, United States
- College of Medicine, Georgetown University, Washington, D.C. 20057, United States
| | - Sally A. Litherland
- Translational Research, Florida Hospital Cancer Institute, Orlando, Florida 32804, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
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Maryanoff BE, Wipf P. Presenting a Special Issue on "Medicinal Chemistry: From Targets to Therapies". ACS Med Chem Lett 2020; 11:1780-1782. [PMID: 33062151 PMCID: PMC7549098 DOI: 10.1021/acsmedchemlett.0c00508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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