title: A Duplexed High-Throughput Screen to Identify Allosteric Modulators of the Glucagon-Like Peptide 1 and Glucagon Receptors.
abstract: Injectable, degradation-resistant peptide agonists for the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R), such as exenatide and liraglutide, activate the GLP-1R via a complex orthosteric-binding site and are effective therapeutics for glycemic control in type 2 diabetes. Orally bioavailable orthosteric small-molecule agonists are unlikely to be developed, whereas positive allosteric modulators (PAMs) may offer an improved therapeutic profile. We hypothesize that allosteric modulators of the GLP-1R would increase the potency and efficacy of native GLP-1 in a spatial and temporally preserved manner and/or may improve efficacy or side effects of injectable analogs. We report the design, optimization, and initial results of a duplexed high-throughput screen in which cell lines overexpressing either the GLP-1R or the glucagon receptor were coplated, loaded with a calcium-sensitive dye, and probed in a three-phase assay to identify agonists, antagonists, and potentiators of GLP-1, and potentiators of glucagon. 175,000 compounds were initially screened, and progression through secondary assays yielded 98 compounds with a variety of activities at the GLP-1R. Here, we describe five compounds possessing different patterns of modulation of the GLP-1R. These data uncover PAMs that may offer a drug-development pathway to enhancing in vivo efficacy of both endogenous GLP-1 and peptide analogs.
authors: Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: Lindsey C
authors: LC
authors: Morris
authors: Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: Emily L
authors: EL
authors: Days
authors: Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: Maxine
authors: M
authors: Turney
authors: Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: Dehui
authors: D
authors: Mi
authors: Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, TN, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: Craig W
authors: CW
authors: Lindsley
authors: Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors: C David
authors: CD
authors: Weaver
authors: Tennessee Valley Healthcare System, Nashville, TN, USA Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA kevin.niswender@vanderbilt.edu.
authors: Kevin D
authors: KD
authors: Niswender
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects; D000495:Allosteric Site; D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002118:Calcium / Q000737:chemistry; D002460:Cell Line; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000737:chemistry; D018450:Disease Progression; D000077270:Exenatide; D052216:Glucagon-Like Peptide 1 / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D000069450:Liraglutide / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D018027:Receptors, Glucagon / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D015398:Signal Transduction; D014688:Venoms / Q000737:chemistry
chemical_list: D010455:Peptides; D018027:Receptors, Glucagon; D011994:Recombinant Proteins; D014688:Venoms; D000069450:Liraglutide; D052216:Glucagon-Like Peptide 1; D000077270:Exenatide; D000242:Cyclic AMP; D005947:Glucose; D002118:Calcium
keywords: High-throughput screening; agonist; calcium; glucagon-like peptide-1 receptor; positive allosteric modulator