1
|
Zhao LH, He Q, Yuan Q, Gu Y, He X, Shan H, Li J, Wang K, Li Y, Hu W, Wu K, Shen J, Xu HE. Conserved class B GPCR activation by a biased intracellular agonist. Nature 2023; 621:635-641. [PMID: 37524305 DOI: 10.1038/s41586-023-06467-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 07/20/2023] [Indexed: 08/02/2023]
Abstract
Class B G-protein-coupled receptors (GPCRs), including glucagon-like peptide 1 receptor (GLP1R) and parathyroid hormone 1 receptor (PTH1R), are important drug targets1-5. Injectable peptide drugs targeting these receptors have been developed, but orally available small-molecule drugs remain under development6,7. Here we report the high-resolution structure of human PTH1R in complex with the stimulatory G protein (Gs) and a small-molecule agonist, PCO371, which reveals an unexpected binding mode of PCO371 at the cytoplasmic interface of PTH1R with Gs. The PCO371-binding site is totally different from all binding sites previously reported for small molecules or peptide ligands in GPCRs. The residues that make up the PCO371-binding pocket are conserved in class B GPCRs, and a single alteration in PTH2R and two residue alterations in GLP1R convert these receptors to respond to PCO371. Functional assays reveal that PCO371 is a G-protein-biased agonist that is defective in promoting PTH1R-mediated arrestin signalling. Together, these results uncover a distinct binding site for designing small-molecule agonists for PTH1R and possibly other members of the class B GPCRs and define a receptor conformation that is specific only for G-protein activation but not arrestin signalling. These insights should facilitate the design of distinct types of class B GPCR small-molecule agonist for various therapeutic indications.
Collapse
MESH Headings
- Humans
- Arrestin/metabolism
- Binding Sites
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Imidazolidines/pharmacology
- Ligands
- Peptides/pharmacology
- Protein Conformation
- Receptor, Parathyroid Hormone, Type 1/agonists
- Receptor, Parathyroid Hormone, Type 1/classification
- Receptor, Parathyroid Hormone, Type 1/metabolism
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/classification
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction/drug effects
- Spiro Compounds/pharmacology
- Drug Design
Collapse
Affiliation(s)
- Li-Hua Zhao
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Qian He
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qingning Yuan
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yimin Gu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hong Shan
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Junrui Li
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kai Wang
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yang Li
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wen Hu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kai Wu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jianhua Shen
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - H Eric Xu
- State Key Laboratory of Drug Research, Center for Structure and Function of Drug Targets, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
2
|
Puri S, Kenyon BM, Hamrah P. Immunomodulatory Role of Neuropeptides in the Cornea. Biomedicines 2022; 10:1985. [PMID: 36009532 PMCID: PMC9406019 DOI: 10.3390/biomedicines10081985] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 12/21/2022] Open
Abstract
The transparency of the cornea along with its dense sensory innervation and resident leukocyte populations make it an ideal tissue to study interactions between the nervous and immune systems. The cornea is the most densely innervated tissue of the body and possesses both immune and vascular privilege, in part due to its unique repertoire of resident immune cells. Corneal nerves produce various neuropeptides that have a wide range of functions on immune cells. As research in this area expands, further insights are made into the role of neuropeptides and their immunomodulatory functions in the healthy and diseased cornea. Much remains to be known regarding the details of neuropeptide signaling and how it contributes to pathophysiology, which is likely due to complex interactions among neuropeptides, receptor isoform-specific signaling events, and the inflammatory microenvironment in disease. However, progress in this area has led to an increase in studies that have begun modulating neuropeptide activity for the treatment of corneal diseases with promising results, necessitating the need for a comprehensive review of the literature. This review focuses on the role of neuropeptides in maintaining the homeostasis of the ocular surface, alterations in disease settings, and the possible therapeutic potential of targeting these systems.
Collapse
Affiliation(s)
- Sudan Puri
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Brendan M. Kenyon
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
- Departments of Immunology and Neuroscience, Tufts University School of Medicine, Boston, MA 02111, USA
- Cornea Service, Tufts New England Eye Center, Boston, MA 02111, USA
| |
Collapse
|
3
|
Discovery of small molecule positive allosteric modulators of the secretin receptor. Biochem Pharmacol 2021; 185:114451. [PMID: 33545115 DOI: 10.1016/j.bcp.2021.114451] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022]
Abstract
The secretin receptor (SCTR) is a prototypic Class B1 G protein-coupled receptor (GPCR) that represents a key target for the development of therapeutics for the treatment of cardiovascular, gastrointestinal, and metabolic disorders. However, no non-peptidic molecules targeting this receptor have yet been disclosed. Using a high-throughput screening campaign directed at SCTR to identify small molecule modulators, we have identified three structurally related scaffolds positively modulating SCTRs. Here we outline a comprehensive study comprising a structure-activity series based on commercially available analogs of the three hit scaffold sets A (2-sulfonyl pyrimidines), B (2-mercapto pyrimidines) and C (2-amino pyrimidines), which revealed determinants of activity, cooperativity and specificity. Structural optimization of original hits resulted in analog B2, which substantially enhances signaling of truncated secretin peptides and prolongs residence time of labeled secretin up to 13-fold in a dose-dependent manner. Furthermore, we found that investigated compounds display structural similarity to positive allosteric modulators (PAMs) active at the glucagon-like peptide-1 receptor (GLP-1R), and we were able to confirm cross-recognition of that receptor by a subset of analogs. Studies using SCTR and GLP-1R mutants revealed that scaffold A, but not B and C, likely acts via two distinct mechanisms, one of which constitutes covalent modification of Cys-347GLP-1R known from GLP-1R-selective modulators. The scaffolds identified in this study might not only serve as novel pharmacologic tools to decipher SCTR- or GLP-1R-specific signaling pathways, but also as structural leads to elucidate allosteric binding sites facilitating the future development of orally available therapeutic approaches targeting these receptors.
Collapse
|
4
|
Dengler DG, Sun Q, Holleran J, Pollari S, Beutel J, Brown BT, Shinoki Iwaya A, Ardecky R, Harikumar KG, Miller LJ, Sergienko EA. Development of a Testing Funnel for Identification of Small-Molecule Modulators Targeting Secretin Receptors. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2021; 26:1-16. [PMID: 32749201 PMCID: PMC8278649 DOI: 10.1177/2472555220945284] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The secretin receptor (SCTR), a prototypical class B G protein-coupled receptor (GPCR), exerts its effects mainly by activating Gαs proteins upon binding of its endogenous peptide ligand secretin. SCTRs can be found in a variety of tissues and organs across species, including the pancreas, stomach, liver, heart, lung, colon, kidney, and brain. Beyond that, modulation of SCTR-mediated signaling has therapeutic potential for the treatment of multiple diseases, such as heart failure, obesity, and diabetes. However, no ligands other than secretin and its peptide analogs have been described to regulate SCTRs, probably due to inherent challenges in family B GPCR drug discovery. Here we report creation of a testing funnel that allowed targeted detection of SCTR small-molecule activators. Pursuing the strategy to identify positive allosteric modulators (PAMs), we established a unique primary screening assay employing a mixture of three orthosteric stimulators that was compared in a screening campaign testing 12,000 small-molecule compounds. Beyond that, we developed a comprehensive set of secondary assays, such as a radiolabel-free target engagement assay and a NanoBiT (NanoLuc Binary Technology)-based approach to detect β-arrestin-2 recruitment, all feasible in a high-throughput environment as well as capable of profiling ligands and hits regarding their effect on binding and receptor function. This combination of methods enabled the discovery of five promising scaffolds, four of which have been validated and further characterized with respect to their allosteric activities. We propose that our results may serve as starting points for developing the first in vivo active small molecules targeting SCTRs.
Collapse
Affiliation(s)
- Daniela G. Dengler
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Qing Sun
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - John Holleran
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Sirkku Pollari
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Jannis Beutel
- Department of Chemistry and Pharmacy, Chemikum, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Brock T. Brown
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Aki Shinoki Iwaya
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Robert Ardecky
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Kaleeckal G. Harikumar
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, USA
| | - Laurence J. Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, USA
| | - Eduard A. Sergienko
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| |
Collapse
|
5
|
Wang J, Song X, Zhang D, Chen X, Li X, Sun Y, Li C, Song Y, Ding Y, Ren R, Harrington EH, Hu LA, Zhong W, Xu C, Huang X, Wang HW, Ma Y. Cryo-EM structures of PAC1 receptor reveal ligand binding mechanism. Cell Res 2020; 30:436-445. [PMID: 32047270 PMCID: PMC7196072 DOI: 10.1038/s41422-020-0280-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/20/2020] [Indexed: 12/24/2022] Open
Abstract
The pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1R) belongs to the secretin receptor family and is widely distributed in the central neural system and peripheral organs. Abnormal activation of the receptor mediates trigeminovascular activation and sensitization, which is highly related to migraine, making PAC1R a potential therapeutic target. Elucidation of PAC1R activation mechanism would benefit discovery of therapeutic drugs for neuronal disorders. PAC1R activity is governed by pituitary adenylate cyclase-activating polypeptide (PACAP), known as a major vasodilator neuropeptide, and maxadilan, a native peptide from the sand fly, which is also capable of activating the receptor with similar potency. These peptide ligands have divergent sequences yet initiate convergent PAC1R activity. It is of interest to understand the mechanism of PAC1R ligand recognition and receptor activity regulation through structural biology. Here we report two near-atomic resolution cryo-EM structures of PAC1R activated by PACAP38 or maxadilan, providing structural insights into two distinct ligand binding modes. The structures illustrate flexibility of the extracellular domain (ECD) for ligands with distinct conformations, where ECD accommodates ligands in different orientations while extracellular loop 1 (ECL1) protrudes to further anchor the ligand bound in the orthosteric site. By structure-guided molecular modeling and mutagenesis, we tested residues in the ligand-binding pockets and identified clusters of residues that are critical for receptor activity. The structures reported here for the first time elucidate the mechanism of specificity and flexibility of ligand recognition and binding for PAC1R, and provide insights toward the design of therapeutic molecules targeting PAC1R.
Collapse
Affiliation(s)
- Jia Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xianqiang Song
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Dandan Zhang
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Xiaoqing Chen
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Xun Li
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yaping Sun
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Cui Li
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yunpeng Song
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Yao Ding
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Ruobing Ren
- School of Life and Health Sciences, Kobilka Institute of Innovative Drug Discovery, The Chinese University of Hong Kong, Tu H.L. Building (Research Building B) R705, Longxiang Road 2001, Longgang district, Shenzhen, 518172, Guangdong, China
| | - Essa Hu Harrington
- Hybrid Modality Engineering, Therapeutic Discovery, Amgen Research, One Amgen Center Dr., Thousand Oaks, CA, 91320, USA
| | - Liaoyuan A Hu
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Wenge Zhong
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China
| | - Cen Xu
- Department of Neuroscience, Amgen Research, One Amgen Center Dr., Thousand Oaks, CA, 91320, USA
| | - Xin Huang
- Molecular Engineering, Therapeutic Discovery, Amgen Research, 360 Binney Street, Cambridge, MA, 02142, USA
| | - Hong-Wei Wang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Yingli Ma
- Amgen Asia R&D Center, Amgen Research, Bldg. 2, 13th Floor, No. 4560 Jinke Road, Shanghai, 201210, China.
| |
Collapse
|
6
|
Wootten D, Miller LJ. Structural Basis for Allosteric Modulation of Class B G Protein-Coupled Receptors. Annu Rev Pharmacol Toxicol 2019; 60:89-107. [PMID: 31454292 DOI: 10.1146/annurev-pharmtox-010919-023301] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recent advances in our understanding of the structure and function of class B G protein-coupled receptors (GPCRs) provide multiple opportunities for targeted development of allosteric modulators. Given the pleiotropic signaling patterns emanating from these receptors in response to a variety of natural agonist ligands, modulators have the potential to sculpt the responses to meet distinct needs of different groups of patients. In this review, we provide insights into how this family of GPCRs differs from the rest of the superfamily, how orthosteric agonists bind and activate these receptors, the potential for allosteric modulators to interact with various regions of these targets, and the allosteric influence of endogenous proteins on the pharmacology of these receptors, all of which are important considerations when developing new therapies.
Collapse
Affiliation(s)
- Denise Wootten
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, and Department of Pharmacology, Monash University, Parkville 3052, Australia; .,School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Laurence J Miller
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, and Department of Pharmacology, Monash University, Parkville 3052, Australia; .,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259, USA;
| |
Collapse
|
7
|
Szlenk CT, Gc JB, Natesan S. Does the Lipid Bilayer Orchestrate Access and Binding of Ligands to Transmembrane Orthosteric/Allosteric Sites of G Protein-Coupled Receptors? Mol Pharmacol 2019; 96:527-541. [PMID: 30967440 DOI: 10.1124/mol.118.115113] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 04/03/2019] [Indexed: 01/08/2023] Open
Abstract
The ligand-binding sites of many G protein-coupled receptors (GPCRs) are situated around and deeply embedded within the central pocket formed by their seven transmembrane-spanning α-helical domains. Generally, these binding sites are assumed accessible to endogenous ligands from the aqueous phase. Recent advances in the structural biology of GPCRs, along with biophysical and computational studies, suggest that amphiphilic and lipophilic molecules may gain access to these receptors by first partitioning into the membrane and then reaching the binding site via lateral diffusion through the lipid bilayer. In addition, several crystal structures of class A and class B GPCRs bound to their ligands offer unprecedented details on the existence of lipid-facing allosteric binding sites outside the transmembrane helices that can only be reached via lipid pathways. The highly organized structure of the lipid bilayer may direct lipophilic or amphiphilic drugs to a specific depth within the bilayer, changing local concentration of the drug near the binding site and affecting its binding kinetics. Additionally, the constraints of the lipid bilayer, including its composition and biophysical properties, may play a critical role in "pre-organizing" ligand molecules in an optimal orientation and conformation to facilitate receptor binding. Despite its clear involvement in molecular recognition processes, the critical role of the membrane in binding ligands to lipid-exposed transmembrane binding sites remains poorly understood and warrants comprehensive investigation. Understanding the mechanistic basis of the structure-membrane interaction relationship of drugs will not only provide useful insights about receptor binding kinetics but will also enhance our ability to take advantage of the apparent membrane contributions when designing drugs that target transmembrane proteins with improved efficacy and safety. In this minireview, we summarize recent structural and computational studies on membrane contributions to binding processes, elucidating both lipid pathways of ligand access and binding mechanisms for several orthosteric and allosteric ligands of class A and class B GPCRs.
Collapse
Affiliation(s)
- Christopher T Szlenk
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Jeevan B Gc
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Senthil Natesan
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| |
Collapse
|
8
|
Yap MKK, Misuan N. Exendin‐4 from
Heloderma suspectum
venom: From discovery to its latest application as type
II
diabetes combatant. Basic Clin Pharmacol Toxicol 2018; 124:513-527. [DOI: 10.1111/bcpt.13169] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/01/2018] [Indexed: 02/06/2023]
Affiliation(s)
| | - Nurhamimah Misuan
- School of ScienceMonash University MalaysiaJalan Lagoon Selatan Bandar Sunway Malaysia
| |
Collapse
|
9
|
Wootten D, Miller LJ, Koole C, Christopoulos A, Sexton PM. Allostery and Biased Agonism at Class B G Protein-Coupled Receptors. Chem Rev 2016; 117:111-138. [PMID: 27040440 DOI: 10.1021/acs.chemrev.6b00049] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Class B G protein-coupled receptors (GPCRs) respond to paracrine or endocrine peptide hormones involved in control of bone homeostasis, glucose regulation, satiety, and gastro-intestinal function, as well as pain transmission. These receptors are targets for existing drugs that treat osteoporosis, hypercalcaemia, Paget's disease, type II diabetes, and obesity and are being actively pursued as targets for numerous other diseases. Exploitation of class B receptors has been limited by difficulties with small molecule drug discovery and development and an under appreciation of factors governing optimal therapeutic efficacy. Recently, there has been increasing awareness of novel attributes of GPCR function that offer new opportunity for drug development. These include the presence of allosteric binding sites on the receptor that can be exploited as drug binding pockets and the ability of individual drugs to enrich subpopulations of receptor conformations to selectively control signaling, a phenomenon termed biased agonism. In this review, current knowledge of biased signaling and small molecule allostery within class B GPCRs is discussed, highlighting areas that have progressed significantly over the past decade, in addition to those that remain largely unexplored with respect to these phenomena.
Collapse
Affiliation(s)
- Denise Wootten
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
| | - Laurence J Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic , Scottsdale, Arizona 85259, United States
| | - Cassandra Koole
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia.,Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University , New York, New York 10065, United States
| | - Arthur Christopoulos
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville 3052, Victoria, Australia
| |
Collapse
|
10
|
Vauquelin G, Van Liefde I, Swinney DC. On the different experimental manifestations of two-state 'induced-fit' binding of drugs to their cellular targets. Br J Pharmacol 2016; 173:1268-85. [PMID: 26808227 DOI: 10.1111/bph.13445] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/03/2015] [Accepted: 01/12/2016] [Indexed: 01/17/2023] Open
Abstract
'Induced-fit' binding of drugs to a target may lead to high affinity, selectivity and a long residence time, and this mechanism has been proposed to apply to many drugs with high clinical efficacy. It is a multistep process that initially involves the binding of a drug to its target to form a loose RL complex and a subsequent isomerization/conformational change to yield a tighter binding R'L state. Equations with the same mathematical form may also describe the binding of bivalent antibodies and related synthetic drugs. Based on a selected range of 'microscopic' rate constants and variables such as the ligand concentration and incubation time, we have simulated the experimental manifestations that may go along with induced-fit binding. Overall, they validate different experimental procedures that have been used over the years to identify such binding mechanisms. However, they also reveal that each of these manifestations only becomes perceptible at particular combinations of rate constants. The simulations also show that the durable nature of R'L and the propensity of R'L to be formed repeatedly before the ligand dissociates will increase the residence time. This review may help pharmacologists and medicinal chemists obtain preliminary indications for identifying an induced-fit mechanism.
Collapse
Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Isabelle Van Liefde
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium
| | - David C Swinney
- Institute for Rare and Neglected Diseases Drug Discovery, Mountain View, CA, USA
| |
Collapse
|
11
|
Gardella TJ, Vilardaga JP. International Union of Basic and Clinical Pharmacology. XCIII. The parathyroid hormone receptors--family B G protein-coupled receptors. Pharmacol Rev 2015; 67:310-37. [PMID: 25713287 DOI: 10.1124/pr.114.009464] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The type-1 parathyroid hormone receptor (PTHR1) is a family B G protein-coupled receptor (GPCR) that mediates the actions of two polypeptide ligands; parathyroid hormone (PTH), an endocrine hormone that regulates the levels of calcium and inorganic phosphate in the blood by acting on bone and kidney, and PTH-related protein (PTHrP), a paracrine-factor that regulates cell differentiation and proliferation programs in developing bone and other tissues. The type-2 parathyroid hormone receptor (PTHR2) binds a peptide ligand, called tuberoinfundibular peptide-39 (TIP39), and while the biologic role of the PTHR2/TIP39 system is not as defined as that of the PTHR1, it likely plays a role in the central nervous system as well as in spermatogenesis. Mechanisms of action at these receptors have been explored through a variety of pharmacological and biochemical approaches, and the data obtained support a basic "two-site" mode of ligand binding now thought to be used by each of the family B peptide hormone GPCRs. Recent crystallographic studies on the family B GPCRs are providing new insights that help to further refine the specifics of the overall receptor architecture and modes of ligand docking. One intriguing pharmacological finding for the PTHR1 is that it can form surprisingly stable complexes with certain PTH/PTHrP ligand analogs and thereby mediate markedly prolonged cell signaling responses that persist even when the bulk of the complexes are found in internalized vesicles. The PTHR1 thus appears to be able to activate the Gα(s)/cAMP pathway not only from the plasma membrane but also from the endosomal domain. The cumulative findings could have an impact on efforts to develop new drug therapies for the PTH receptors.
Collapse
Affiliation(s)
- Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
| | - Jean-Pierre Vilardaga
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
| |
Collapse
|
12
|
Vauquelin G. On the 'micro'-pharmacodynamic and pharmacokinetic mechanisms that contribute to long-lasting drug action. Expert Opin Drug Discov 2015; 10:1085-98. [PMID: 26165720 DOI: 10.1517/17460441.2015.1067196] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Optimal drug therapy often requires continuing high levels of target occupancy. Besides the traditional pharmacokinetic (PK) contribution thereto, drug-target interactions that comprise successive 'microscopic' steps as well as the intervention of the cell membrane and other 'micro'-anatomical structures nearby may help attaining this objective. AREAS COVERED This article reviews the 'micro'-pharmacodynamic (PD) and PK mechanisms that may increase a drug's residence time. Special focus is on induced-fit- and bivalent ligand binding models as well as on the ability of the plasma membrane surrounding the target to act as a repository for the drug (e.g., microkinetic model), to actively participate in the binding process (e.g., exosite model) and, along with microanatomical elements like synapses and interstitial spaces, to act on the drug's diffusion properties (reduction in dimensionality and drug-rebinding models). EXPERT OPINION The PK profile, as well as the target dissociation kinetics of a drug, may fail to account for its long-lasting efficiency in intact tissues and in vivo. This lacuna could potentially be alleviated by incorporating some of the enumerated 'microscopic' mechanisms and, to unveil them, dedicated experiments on sufficiently physiologically relevant biological material like cell monolayers can already be implemented early on in the lead optimization process.
Collapse
Affiliation(s)
- Georges Vauquelin
- a Free University Brussels (VUB), Molecular and Biochemical Pharmacology Department , Pleinlaan 2, B-1050 Brussels, Belgium +32 2 6291955 ; +32 2 6291358 ;
| |
Collapse
|
13
|
Vauquelin G, Hall D, Charlton SJ. 'Partial' competition of heterobivalent ligand binding may be mistaken for allosteric interactions: a comparison of different target interaction models. Br J Pharmacol 2015; 172:2300-15. [PMID: 25537684 DOI: 10.1111/bph.13053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 10/25/2014] [Accepted: 12/14/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Non-competitive drugs that confer allosteric modulation of orthosteric ligand binding are of increasing interest as therapeutic agents. Sought-after advantages include a ceiling level to drug effect and greater receptor-subtype selectivity. It is thus important to determine the mode of interaction of newly identified receptor ligands early in the drug discovery process and binding studies with labelled orthosteric ligands constitute a traditional approach for this. According to the general allosteric ternary complex model, allosteric ligands that exhibit negative cooperativity may generate distinctive 'competition' curves: they will not reach baseline levels and their nadir will increase in par with the orthosteric ligand concentration. This behaviour is often considered a key hallmark of allosteric interactions. EXPERIMENTAL APPROACH The present study is based on differential equation-based simulations. KEY RESULTS The differential equation-based simulations revealed that the same 'competition binding' pattern was also obtained when a monovalent ligand binds to one of the target sites of a heterobivalent ligand, even if this process is exempt of allosteric interactions. This pattern was not strictly reciprocal when the binding of each of the ligands was recorded. The prominence of this phenomenon may vary from one heterobivalent ligand to another and we suggest that this phenomenon may take place with ligands that have been proposed to bind according to 'two-domain' and 'charnière' models. CONCLUSIONS AND IMPLICATIONS The present findings indicate a familiar experimental situation where bivalency may give rise to observations that could inadvertently be interpreted as allosteric binding. Yet, both mechanisms could be differentiated based on alternative experiments and structural considerations.
Collapse
Affiliation(s)
- Georges Vauquelin
- Department Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium
| | | | | |
Collapse
|
14
|
Carter PH, Dean T, Bhayana B, Khatri A, Rajur R, Gardella TJ. Actions of the small molecule ligands SW106 and AH-3960 on the type-1 parathyroid hormone receptor. Mol Endocrinol 2015; 29:307-21. [PMID: 25584411 DOI: 10.1210/me.2014-1129] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The parathyroid hormone receptor-1 (PTHR1) plays critical roles in regulating blood calcium levels and bone metabolism and is thus of interest for small-molecule ligand development. Of the few small-molecule ligands reported for the PTHR1, most are of low affinity, and none has a well-defined mechanism of action. Here, we show that SW106 and AH-3960, compounds previously identified to act as an antagonist and agonist, respectively, on the PTHR1, each bind to PTHR1-delNT, a PTHR1 construct that lacks the large amino-terminal extracellular domain used for binding endogenous PTH peptide ligands, with the same micromolar affinity with which it binds to the intact PTHR1. SW106 antagonized PTHR1-mediated cAMP signaling induced by the peptide analog, M-PTH(1-11), as well as by the native PTH(1-9) sequence, as tethered to the extracellular end of transmembrane domain (TMD) helix-1 of the receptor. SW106, however, did not function as an inverse agonist on either PTHR1-H223R or PTHR1-T410P, which have activating mutations at the cytoplasmic ends of TMD helices 2 and 6, respectively. The overall data indicate that SW106 and AH-3960 each bind to the PTHR1 TMD region and likely to within an extracellularly exposed area that is occupied by the N-terminal residues of PTH peptides. Additionally, they suggest that the inhibitory effects of SW106 are limited to the extracellular portions of the TMD region that mediate interactions with agonist ligands but do not extend to receptor-activation determinants situated more deeply in the helical bundle. The study helps to elucidate potential mechanisms of small-molecule binding at the PTHR1.
Collapse
Affiliation(s)
- Percy H Carter
- Endocrine Unit (T.D., A.K., T.J.G.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02492; Department of Photomedicine (B.B.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02492; CreaGen Biosciences, Inc (R.R.), Woburn, Massachusetts 01801; and Bristol-Myers Squibb Co (P.H.C.), Princeton, New Jersey 08543
| | | | | | | | | | | |
Collapse
|
15
|
Bradley ME, Dombrecht B, Manini J, Willis J, Vlerick D, De Taeye S, Van den Heede K, Roobrouck A, Grot E, Kent TC, Laeremans T, Steffensen S, Van Heeke G, Brown Z, Charlton SJ, Cromie KD. Potent and Efficacious Inhibition of CXCR2 Signaling by Biparatopic Nanobodies Combining Two Distinct Modes of Action. Mol Pharmacol 2014; 87:251-62. [DOI: 10.1124/mol.114.094821] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
|
16
|
Morris LC, Days EL, Turney M, Mi D, Lindsley CW, Weaver CD, Niswender KD. A Duplexed High-Throughput Screen to Identify Allosteric Modulators of the Glucagon-Like Peptide 1 and Glucagon Receptors. JOURNAL OF BIOMOLECULAR SCREENING 2014; 19:847-58. [PMID: 24525870 PMCID: PMC4306651 DOI: 10.1177/1087057114520971] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/31/2013] [Indexed: 11/16/2022]
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.
Collapse
Affiliation(s)
- Lindsey C Morris
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Emily L Days
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Maxine Turney
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Dehui Mi
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Craig W Lindsley
- 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
| | - C David Weaver
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kevin D Niswender
- Tennessee Valley Healthcare System, Nashville, TN, USA Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| |
Collapse
|
17
|
Nadkarni P, Chepurny OG, Holz GG. Regulation of glucose homeostasis by GLP-1. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014. [PMID: 24373234 DOI: 10.1016/b978-0-12-800101-1.00002-8.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/01/2022]
Abstract
Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics.
Collapse
Affiliation(s)
- Prashant Nadkarni
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA; Joslin Diabetes Center, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - George G Holz
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA; Department of Pharmacology, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA.
| |
Collapse
|
18
|
Nadkarni P, Chepurny OG, Holz GG. Regulation of glucose homeostasis by GLP-1. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 121:23-65. [PMID: 24373234 DOI: 10.1016/b978-0-12-800101-1.00002-8] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Glucagon-like peptide-1(7-36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeostasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics.
Collapse
Affiliation(s)
- Prashant Nadkarni
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA; Joslin Diabetes Center, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA
| | - George G Holz
- Department of Medicine, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA; Department of Pharmacology, State University of New York (SUNY), Upstate Medical University, Syracuse, New York, USA.
| |
Collapse
|
19
|
Vauquelin G, Bricca G, Van Liefde I. Avidity and positive allosteric modulation/cooperativity act hand in hand to increase the residence time of bivalent receptor ligands. Fundam Clin Pharmacol 2013; 28:530-43. [PMID: 24118041 DOI: 10.1111/fcp.12052] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 09/09/2013] [Accepted: 09/27/2013] [Indexed: 11/30/2022]
Abstract
Bivalent ligands bear two target-binding pharmacophores. Their simultaneous binding increases their affinity (avidity) and residence time. They become 'bitopic' when the binding sites at the target permit the pharmacophores the exert allosteric modulation of each other's affinity and/or activity. Present simulations reveal that positive cooperativity exacerbates these phenomena, whereas negative cooperativity curtails them, irrespective of whether the association or dissociation rates of the individual pharmacophores are affected. Positive cooperativity delays the attainment of equilibrium binding, yielding 'hemi-equilibrium' conditions and only apparent affinity constants under usual experimental conditions. Monovalent ligands that bind to one of the target sites decrease the bitopic ligand's residence time concentration-wise; their potency depends on their association rate and thereon acting cooperativity rather than on affinity. This stems from the repetitive, very fast reformation of fully bound bitopic ligand-target complexes by rebinding of freshly dissociated pharmacophores. These studies deal with kinetic binding properties (of increasing interest in pharmacology) of bitopic ligands (a promising avenue in medicinal chemistry).
Collapse
Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Institute for Molecular Biology and Biotechnology, Free University of Brussels (VUB), Pleinlaan 2, B-1050, Brussels, Belgium
| | | | | |
Collapse
|
20
|
Mukund S, Shang Y, Clarke HJ, Madjidi A, Corn JE, Kates L, Kolumam G, Chiang V, Luis E, Murray J, Zhang Y, Hötzel I, Koth CM, Allan BB. Inhibitory mechanism of an allosteric antibody targeting the glucagon receptor. J Biol Chem 2013; 288:36168-78. [PMID: 24189067 PMCID: PMC3861664 DOI: 10.1074/jbc.m113.496984] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Elevated glucagon levels and increased hepatic glucagon receptor (GCGR) signaling contribute to hyperglycemia in type 2 diabetes. We have identified a monoclonal antibody that inhibits GCGR, a class B G-protein coupled receptor (GPCR), through a unique allosteric mechanism. Receptor inhibition is mediated by the binding of this antibody to two distinct sites that lie outside of the glucagon binding cleft. One site consists of a patch of residues that are surface-exposed on the face of the extracellular domain (ECD) opposite the ligand-binding cleft, whereas the second binding site consists of residues in the αA helix of the ECD. A docking model suggests that the antibody does not occlude the ligand-binding cleft. We solved the crystal structure of GCGR ECD containing a naturally occurring G40S mutation and found a shift in the register of the αA helix that prevents antibody binding. We also found that alterations in the αA helix impact the normal function of GCGR. We present a model for the allosteric inhibition of GCGR by a monoclonal antibody that may form the basis for the development of allosteric modulators for the treatment of diabetes and other class B GPCR-related diseases.
Collapse
|
21
|
Weaver CD. Triple-addition assay protocols for detecting and characterizing modulators of seven-transmembrane receptors. ACTA ACUST UNITED AC 2013; 3:119-40. [PMID: 23801564 DOI: 10.1002/9780470559277.ch110060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The detection and characterization of seven-transmembrane-receptor modulators (orthosteric binding site agonists, antagonists, and more recently allosteric modulators) is an area of intense interest for both drug discovery and basic research. Traditionally, assays used to detect and characterize these different modes of modulation have been executed as separate, discrete protocols focused on a particular mode of action (e.g., agonism). In recent years, investigators have begun to combine aspects of these separate protocols to produce methods that detect multiple modes of modulation simultaneously. The power of such approaches is revealed not only in conservation of time and resources, but more importantly in a superior ability to discover and characterize novel modulators of the targets of interest. The protocols in this article describe a general procedure for developing, validating, and utilizing triple-addition assays to enable the simultaneous detection and characterization of multiple modes of seven-transmembrane-receptor modulation. Curr. Protoc. Chem. Biol. 3:119-140 © 2011 by John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- C David Weaver
- Vanderbilt University School of Medicine, Nashville, Tennessee
| |
Collapse
|
22
|
Vauquelin G. Simplified models for heterobivalent ligand binding: when are they applicable and which are the factors that affect their target residence time. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:949-62. [DOI: 10.1007/s00210-013-0881-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/05/2013] [Indexed: 01/27/2023]
|
23
|
Compeer MG, Meens MJPMT, Hackeng TM, Neugebauer WA, Höltke C, De Mey JGR. Agonist-dependent modulation of arterial endothelinA receptor function. Br J Pharmacol 2012; 166:1833-45. [PMID: 22324472 DOI: 10.1111/j.1476-5381.2012.01896.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Endothelin-1 (ET-1) causes long-lasting vasoconstrictions. These can be prevented by ET(A) receptor antagonists but are only poorly reversed by these drugs. We tested the hypothesis that endothelin ET(A) receptors are susceptible to allosteric modulation by endogenous agonists and exogenous ligands. EXPERIMENTAL APPROACH Rat isolated mesenteric resistance arteries were pretreated with capsaicin and studied in wire myographs, in the presence of L-NAME and indomethacin to concentrate on arterial smooth muscle responses. KEY RESULTS Endothelins caused contractions with equal maximum but differing potency (ET-1 = ET-2 > ET-3). ET-1(1-15) neither mimicked nor antagonized these effects in the absence and presence of ET(16-21). 4(Ala) ET-1 (ET(B) agonist) and BQ788 (ET(B) antagonist) were without effects. BQ123 (peptide ET(A) antagonist) reduced the sensitivity and relaxed the contractile responses to endothelins. Both effects depended on the agonist (pK(B): ET-3 = ET-1 > ET-2; % relaxation: ET-3 = ET-2 > ET-1). Also, with PD156707 (non-peptide ET(A) antagonist) agonist-dependence and a discrepancy between preventive and inhibitory effects were observed. The latter was even more marked with bulky analogues of BQ123 and PD156707. CONCLUSIONS AND IMPLICATIONS These findings indicate allosteric modulation of arterial smooth muscle ET(A) receptor function by endogenous agonists and by exogenous endothelin receptor antagonists. This may have consequences for the diagnosis and pharmacotherapy of diseases involving endothelins.
Collapse
Affiliation(s)
- M G Compeer
- Department of Pharmacology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | | | | | | | | | | |
Collapse
|
24
|
Glucagon-like peptide-1 receptor dimerization differentially regulates agonist signaling but does not affect small molecule allostery. Proc Natl Acad Sci U S A 2012; 109:18607-12. [PMID: 23091034 DOI: 10.1073/pnas.1205227109] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The glucagon-like peptide-1 receptor (GLP-1R) is a family B G protein-coupled receptor and an important drug target for the treatment of type II diabetes, with activation of pancreatic GLP-1Rs eliciting glucose-dependent insulin secretion. Currently, approved therapeutics acting at this receptor are peptide based, and there is substantial interest in small molecule modulators for the GLP-1R. Using a variety of resonance energy transfer techniques, we demonstrate that the GLP-1R forms homodimers and that transmembrane helix 4 (TM4) provides the primary dimerization interface. We show that disruption of dimerization using a TM4 peptide, a minigene construct encoding TM4, or by mutation of TM4, eliminates G protein-dependent high-affinity binding to GLP-1(7-36)NH(2) but has selective effects on receptor signaling. There was <10-fold decrease in potency in cAMP accumulation or ERK1/2 phosphorylation assays but marked loss of intracellular calcium mobilization by peptide agonists. In contrast, there was near-complete abrogation of the cAMP response to an allosteric agonist, compound 2, but preservation of ERK phosphorylation. Collectively, this indicates that GLP-1R dimerization is important for control of signal bias. Furthermore, we reveal that two small molecule ligands are unaltered in their ability to allosterically modulate signaling from peptide ligands, demonstrating that these modulators act in cis within a single receptor protomer, and this has important implications for small molecule drug design.
Collapse
|
25
|
Melancon BJ, Hopkins CR, Wood MR, Emmitte KA, Niswender CM, Christopoulos A, Conn PJ, Lindsley CW. Allosteric modulation of seven transmembrane spanning receptors: theory, practice, and opportunities for central nervous system drug discovery. J Med Chem 2012; 55:1445-64. [PMID: 22148748 DOI: 10.1021/jm201139r] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bruce J Melancon
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | | | | | | | | | | | | | | |
Collapse
|
26
|
de Graaf C, Rein C, Piwnica D, Giordanetto F, Rognan D. Structure-based discovery of allosteric modulators of two related class B G-protein-coupled receptors. ChemMedChem 2011; 6:2159-69. [PMID: 21994134 DOI: 10.1002/cmdc.201100317] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/23/2011] [Indexed: 01/09/2023]
Abstract
Despite the availability of X-ray crystal structure data for several members of the G-protein-coupled receptor (GPCR) superfamily, structure-based discovery of GPCR ligands has been exclusively restricted to class A (rhodopsin-like) receptors. Herein we report the identification, by a docking-based virtual screening approach, of noncompetitive ligands for two related class B (secretin-like) GPCRs: the glucagon receptor (GLR) and the glucagon-like peptide 1 receptor (GLP-1R). Starting from a knowledge-based three-dimensional model of the GLR, a database of 1.9 million commercially available drug-like compounds was screened for chemical similarity to existing GLR noncompetitive antagonists and docked to the transmembrane cavity of the GLR; 23 compounds were then selected based on protein-ligand interaction fingerprints, and were then purchased and evaluated for in vitro binding to GLR and modulation of glucagon-induced cAMP release. Two of the 23 compounds inhibited the effect of glucagon in a dose-dependent manner, with one inhibitor exhibiting the same potency as L-168 049, a reference noncompetitive GLR antagonist, in a whole-cell-based functional assay. Interestingly, one virtual hit that was inactive at the GLR was shown to bind to GLP-1R and potentiate the response to the endogenous GLP-1 ligand.
Collapse
Affiliation(s)
- Chris de Graaf
- Structural Chemogenomics Group, Laboratoire d'Innovation Thérapeutique, UMR 7200 CNRS-UdS, 74 route du Rhin, 67400 Illkirch, France
| | | | | | | | | |
Collapse
|
27
|
Shen DM, Lin S, Parmee ER. A survey of small molecule glucagon receptor antagonists from recent patents (2006 – 2010). Expert Opin Ther Pat 2011; 21:1211-40. [DOI: 10.1517/13543776.2011.587001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
28
|
De Mey JG, Compeer MG, Lemkens P, Meens MJ. ETA-receptor antagonists or allosteric modulators? Trends Pharmacol Sci 2011; 32:345-51. [DOI: 10.1016/j.tips.2011.02.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 02/27/2011] [Accepted: 02/28/2011] [Indexed: 01/14/2023]
|
29
|
Burford NT, Watson J, Bertekap R, Alt A. Strategies for the identification of allosteric modulators of G-protein-coupled receptors. Biochem Pharmacol 2011; 81:691-702. [DOI: 10.1016/j.bcp.2010.12.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/09/2010] [Accepted: 12/10/2010] [Indexed: 11/15/2022]
|
30
|
Rocheville M, Garland SL. An industrial perspective on positive allosteric modulation as a means to discover safe and selective drugs. DRUG DISCOVERY TODAY. TECHNOLOGIES 2010; 7:e1-e94. [PMID: 24103689 DOI: 10.1016/j.ddtec.2010.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
|
31
|
Drugability of extracellular targets: discovery of small molecule drugs targeting allosteric, functional, and subunit-selective sites on GPCRs and ion channels. Neuropsychopharmacology 2009; 34:106-25. [PMID: 18800070 DOI: 10.1038/npp.2008.149] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Beginning with the discovery of the structure of deoxyribose nucleic acid in 1953, by James Watson and Francis Crick, the sequencing of the entire human genome some 50 years later, has begun to quantify the classes and types of proteins that may have relevance to human disease with the promise of rapidly identifying compounds that can modulate these proteins so as to have a beneficial and therapeutic outcome. This so called 'drugable space' involves a variety of membrane-bound proteins including the superfamily of G-protein-coupled receptors (GPCRs), ion channels, and transporters among others. The recent number of novel therapeutics targeting membrane-bound extracellular proteins that have reached the market in the past 20 years however pales in magnitude when compared, during the same timeframe, to the advancements made in the technologies available to aid in the discovery of these novel therapeutics. This review will consider select examples of extracellular drugable targets and focus on the GPCRs and ion channels highlighting the corticotropin releasing factor (CRF) type 1 and gamma-aminobutyric acid receptors, and the Ca(V)2.2 voltage-gated ion channel. These examples will elaborate current technological advancements in drug discovery and provide a prospective framework for future drug development.
Collapse
|