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Dong C, Zheng Y, Long-lyer K, Wright EC, Li Y, Tian L. Fluorescence Imaging of Neural Activity, Neurochemical Dynamics, and Drug-Specific Receptor Conformation with Genetically Encoded Sensors. Annu Rev Neurosci 2022; 45:273-294. [PMID: 35316611 PMCID: PMC9940643 DOI: 10.1146/annurev-neuro-110520-031137] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent advances in fluorescence imaging permit large-scale recording of neural activity and dynamics of neurochemical release with unprecedented resolution in behaving animals. Calcium imaging with highly optimized genetically encoded indicators provides a mesoscopic view of neural activity from genetically defined populations at cellular and subcellular resolutions. Rigorously improved voltage sensors and microscopy allow for robust spike imaging of populational neurons in various brain regions. In addition, recent protein engineering efforts in the past few years have led to the development of sensors for neurotransmitters and neuromodulators. Here, we discuss the development and applications of these genetically encoded fluorescent indicators in reporting neural activity in response to various behaviors in different biological systems as well as in drug discovery. We also report a simple model to guide sensor selection and optimization.
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Affiliation(s)
- Chunyang Dong
- Graduate Program in Biochemistry, Molecular, Cellular, and Developmental Biology, University of California, Davis, California, USA.,Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, California, USA;
| | - Yu Zheng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research; and Peking-Tsinghua Center for Life Sciences, Beijing, China;
| | - Kiran Long-lyer
- Neuroscience Graduate Program, University of California Davis, Davis, CA 95618, USA,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Emily C. Wright
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences; PKU-IDG/McGovern Institute for Brain Research; and Peking-Tsinghua Center for Life Sciences, Beijing, China;
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, California, USA;
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2
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Li Q, Kang C. A Practical Perspective on the Roles of Solution NMR Spectroscopy in Drug Discovery. Molecules 2020; 25:molecules25132974. [PMID: 32605297 PMCID: PMC7411973 DOI: 10.3390/molecules25132974] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 06/21/2020] [Accepted: 06/26/2020] [Indexed: 11/26/2022] Open
Abstract
Solution nuclear magnetic resonance (NMR) spectroscopy is a powerful tool to study structures and dynamics of biomolecules under physiological conditions. As there are numerous NMR-derived methods applicable to probe protein–ligand interactions, NMR has been widely utilized in drug discovery, especially in such steps as hit identification and lead optimization. NMR is frequently used to locate ligand-binding sites on a target protein and to determine ligand binding modes. NMR spectroscopy is also a unique tool in fragment-based drug design (FBDD), as it is able to investigate target-ligand interactions with diverse binding affinities. NMR spectroscopy is able to identify fragments that bind weakly to a target, making it valuable for identifying hits targeting undruggable sites. In this review, we summarize the roles of solution NMR spectroscopy in drug discovery. We describe some methods that are used in identifying fragments, understanding the mechanism of action for a ligand, and monitoring the conformational changes of a target induced by ligand binding. A number of studies have proven that 19F-NMR is very powerful in screening fragments and detecting protein conformational changes. In-cell NMR will also play important roles in drug discovery by elucidating protein-ligand interactions in living cells.
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Affiliation(s)
- Qingxin Li
- Guangdong Provincial Engineering Laboratory of Biomass High Value Utilization, Guangdong Provincial Bioengineering Institute (Guangzhou Sugarcane Industry Research Institute), Guangzhou 510316, China
- Correspondence: (Q.L.); (C.K.); Tel.: +86-020-84168436 (Q.L.); +65-64070602 (C.K.)
| | - CongBao Kang
- Experimental Drug Development Centre (EDDC), Agency for Science, Technology and Research (A*STAR), 10 Biopolis Road, Chromos, #05-01, Singapore 138670, Singapore
- Correspondence: (Q.L.); (C.K.); Tel.: +86-020-84168436 (Q.L.); +65-64070602 (C.K.)
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3
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Pandey A, Sarker M, Liu XQ, Rainey JK. Small expression tags enhance bacterial expression of the first three transmembrane segments of the apelin receptor. Biochem Cell Biol 2014; 92:269-78. [PMID: 24943103 DOI: 10.1139/bcb-2014-0009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
G-protein coupled receptors (GPCRs) are inherently dynamic membrane protein modulators of various important cellular signaling cascades. The apelin receptor (AR or APJ) is a class A GPCR involved in numerous physiological processes, implicated in angiogenesis during tumour formation and as a CD4 co-receptor for entry of human immunodeficiency virus type 1 (HIV-1) to cells. Due to the lack of efficient methods to produce full-length GPCRs enriched with nuclear magnetic resonance (NMR) active (15)N, (13)C, and (or) (2)H isotopes, small GPCR fragments typically comprising 1-2 transmembrane segments are frequently studied using NMR spectroscopy. Here, we report successful overexpression of transmembrane segments 1-3 of AR (AR_TM1-3) in the C41(DE3) strain of Escherichia coli using an AT-rich gene tag previously reported to enhance cell-free expression yields. The resulting protein, with 6 additional N-terminal residues due to the expression tag, was purified using high-performance liquid chromatography (HPLC). Far UV circular dichroism spectropolarimetry demonstrates that AR_TM1-3 has the predicted ~40% α-helical character in membrane-mimetic environments. (1)H-(15)N HSQC NMR experiments imply amenability to high-resolution NMR structural characterization and stability in solution for weeks. Notably, this small expression tag approach may also be generally applicable to other membrane proteins that are difficult to express in E. coli.
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Affiliation(s)
- Aditya Pandey
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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4
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Cohen LS, Fracchiolla KE, Becker J, Naider F. Invited review GPCR structural characterization: Using fragments as building blocks to determine a complete structure. Biopolymers 2014; 102:223-43. [DOI: 10.1002/bip.22490] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/24/2014] [Accepted: 03/27/2014] [Indexed: 12/30/2022]
Affiliation(s)
- Leah S. Cohen
- Department of Chemistry; The College of Staten Island, City University of New York (CUNY); Staten Island NY 10314
| | - Katrina E. Fracchiolla
- Department of Chemistry; The College of Staten Island, City University of New York (CUNY); Staten Island NY 10314
| | - Jeff Becker
- Department of Microbiology; University of Tennessee; Knoxville TN 37996
| | - Fred Naider
- Department of Chemistry; The College of Staten Island, City University of New York (CUNY); Staten Island NY 10314
- Department of Biochemistry; The Graduate Center; CUNY NY 10016-4309
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5
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Honarparvar B, Govender T, Maguire GEM, Soliman MES, Kruger HG. Integrated Approach to Structure-Based Enzymatic Drug Design: Molecular Modeling, Spectroscopy, and Experimental Bioactivity. Chem Rev 2013; 114:493-537. [DOI: 10.1021/cr300314q] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Bahareh Honarparvar
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Glenn E. M. Maguire
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Mahmoud E. S. Soliman
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
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6
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Langelaan DN, Reddy T, Banks AW, Dellaire G, Dupré DJ, Rainey JK. Structural features of the apelin receptor N-terminal tail and first transmembrane segment implicated in ligand binding and receptor trafficking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1471-83. [PMID: 23438363 DOI: 10.1016/j.bbamem.2013.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/17/2013] [Accepted: 02/13/2013] [Indexed: 12/20/2022]
Abstract
G-protein coupled receptors (GPCRs) comprise a large family of membrane proteins with rich functional diversity. Signaling through the apelin receptor (AR or APJ) influences the cardiovascular system, central nervous system and glucose regulation. Pathophysiological involvement of apelin has been shown in atherosclerosis, cancer, human immunodeficiency virus-1 (HIV-1) infection and obesity. Here, we present the high-resolution nuclear magnetic resonance (NMR) spectroscopy-based structure of the N-terminus and first transmembrane (TM) segment of AR (residues 1-55, AR55) in dodecylphosphocholine micelles. AR55 consists of two disrupted helices, spanning residues D14-K25 and A29-R55(1.59). Molecular dynamics (MD) simulations of AR built from a hybrid of experimental NMR and homology model-based restraints allowed validation of the AR55 structure in the context of the full-length receptor in a hydrated bilayer. AR55 structural features were functionally probed using mutagenesis in full-length AR through monitoring of apelin-induced extracellular signal-regulated kinase (ERK) phosphorylation in transiently transfected human embryonic kidney (HEK) 293A cells. Residues E20 and D23 form an extracellular anionic face and interact with lipid headgroups during MD simulations in the absence of ligand, producing an ideal binding site for a cationic apelin ligand proximal to the membrane-water interface, lending credence to membrane-catalyzed apelin-AR binding. In the TM region of AR55, N46(1.50) is central to a disruption in helical character. G42(1.46), G45(1.49) and N46(1.50), which are all involved in the TM helical disruption, are essential for proper trafficking of AR. In summary, we introduce a new correlative NMR spectroscopy and computational biochemistry methodology and demonstrate its utility in providing some of the first high-resolution structural information for a peptide-activated GPCR TM domain.
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Affiliation(s)
- David N Langelaan
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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7
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Wheatley M, Wootten D, Conner MT, Simms J, Kendrick R, Logan RT, Poyner DR, Barwell J. Lifting the lid on GPCRs: the role of extracellular loops. Br J Pharmacol 2012; 165:1688-1703. [PMID: 21864311 DOI: 10.1111/j.1476-5381.2011.01629.x] [Citation(s) in RCA: 224] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
GPCRs exhibit a common architecture of seven transmembrane helices (TMs) linked by intracellular loops and extracellular loops (ECLs). Given their peripheral location to the site of G-protein interaction, it might be assumed that ECL segments merely link the important TMs within the helical bundle of the receptor. However, compelling evidence has emerged in recent years revealing a critical role for ECLs in many fundamental aspects of GPCR function, which supported by recent GPCR crystal structures has provided mechanistic insights. This review will present current understanding of the key roles of ECLs in ligand binding, activation and regulation of both family A and family B GPCRs.
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Affiliation(s)
- M Wheatley
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - D Wootten
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - M T Conner
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - J Simms
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - R Kendrick
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - R T Logan
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - D R Poyner
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - J Barwell
- School of Biosciences, University of Birmingham, Birmingham, UKDrug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, AustraliaDepartment of Pharmacology, Monash University, Parkville, Victoria, AustraliaSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
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Potetinova Z, Tantry S, Cohen LS, Caroccia KE, Arshava B, Becker JM, Naider F. Large multiple transmembrane domain fragments of a G protein-coupled receptor: biosynthesis, purification, and biophysical studies. Biopolymers 2012; 98:485-500. [PMID: 23203693 PMCID: PMC3542537 DOI: 10.1002/bip.22122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 06/01/2012] [Accepted: 07/02/2012] [Indexed: 01/04/2023]
Abstract
To conduct biophysical analyses on large domains of GPCRs, multimilligram quantities of highly homogeneous proteins are necessary. This communication discusses the biosynthesis of four transmembrane and five transmembrane-containing fragments of Ste2p, a GPCR recognizing the Saccharomyces cerevisiae tridecapeptide pheromone α-factor. The target fragments contained the predicted four N-terminal Ste2p[G(31) -A(198) ] (4TMN), four C-terminal Ste2p[T(155) -L(340) ] (4TMC), or five C-terminal Ste2p[I(120) -L(340) ] (5TMC) transmembrane segments of Ste2p. 4TMN was expressed as a fusion protein using a modified pMMHa vector in L-arabinose-induced Escherichia coli BL21-AI, and cleaved with cyanogen bromide. 4TMC and 5TMC were obtained by direct expression using a pET21a vector in IPTG-induced E. coli BL21(DE3) cells. 4TMC and 5TMC were biosynthesized on a preparative scale, isolated in multimilligram amounts, characterized by MS and investigated by biophysical methods. CD spectroscopy indicated the expected highly α-helical content for 4TMC and 5TMC in membrane mimetic environments. Tryptophan fluorescence showed that 5TMC integrated into the nonpolar region of 1-stearoyl-2-hydroxy-sn-glycero-3-phospho-(1'-rac-glycerol) micelles. HSQC-TROSY investigations revealed that [(15) N]-labeled 5TMC in 50% trifluoroethanol-d(2) /H(2) O/0.05%-trifluoroacetic acid was stable enough to conduct long multidimensional NMR measurements. The entire Ste2p GPCR was not readily reconstituted from the first two and last five or first three and last four transmembrane domains.
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Affiliation(s)
- Zhanna Potetinova
- Department of Chemistry, College of Staten Island, The City University of New York, Staten Island, NY 10314, USA
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9
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Siderius M, Wal M, Scholten DJ, Smit MJ, Sakmar TP, Leurs R, de Graaf C. Unnatural amino acids for the study of chemokine receptor structure and dynamics. DRUG DISCOVERY TODAY. TECHNOLOGIES 2012; 9:e227-e314. [PMID: 24063744 DOI: 10.1016/j.ddtec.2012.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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10
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Abstract
G protein-coupled receptors (GPCRs) are a large superfamily of membrane bound signaling proteins that hold great pharmaceutical interest. Since experimentally elucidated structures are available only for a very limited number of receptors, homology modeling has become a widespread technique for the construction of GPCR models intended to study the structure-function relationships of the receptors and aid the discovery and development of ligands capable of modulating their activity. Through this chapter, various aspects involved in the constructions of homology models of the serpentine domain of the largest class of GPCRs, known as class A or rhodopsin family, are illustrated. In particular, the chapter provides suggestions, guidelines, and critical thoughts on some of the most crucial aspect of GPCR modeling, including: collection of candidate templates and a structure-based alignment of their sequences; identification and alignment of the transmembrane helices of the query receptor to the corresponding domains of the candidate templates; selection of one or more templates receptor; election of homology or de novo modeling for the construction of specific extracellular and intracellular domains; construction of the 3D models, with special consideration to extracellular regions, disulfide bridges, and interhelical cavity; validation of the models through controlled virtual screening experiments.
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Abstract
In the past two decades, an increasing body of evidence has demonstrated that several G protein-coupled receptor (GPCR)-ligand pairs are critical for normal human reproductive development and function. Patients harboring genetic insults in either the receptors or their cognate ligands have presented with reproductive disorders characterized by varying degrees of GnRH deficiency. These disorders include idiopathic hypogonadotropic hypogonadism (IHH) and Kallmann Syndrome (KS). Conversely, mutations in some of these ligand-receptor pairs have been associated with accelerated reproductive maturation, manifested as central precocious puberty (CPP). To date, a series of elegant studies have characterized four GPCRs that play important roles in the neuroendocrine control of human reproductive development and function: GnRHR, KISS1R, PROKR2 and NK3R. Furthermore, these studies provide insights into the mechanisms by which mutations in these receptors give rise to reproductive disease phenotypes. This report will review mutations identified in GPCRs involved in the neuroendocrine control of the human reproductive axis with the aims of elucidating structure-function relationships of these GPCRs and identifying correlations between these structure-function relationships and the genotypic-phenotypic characterization of the patients.
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Affiliation(s)
- Sekoni D Noel
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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12
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Szymanski DW, Papanastasiou M, Melchior K, Zvonok N, Mercier RW, Janero DR, Thakur GA, Cha S, Wu B, Karger B, Makriyannis A. Mass spectrometry-based proteomics of human cannabinoid receptor 2: covalent cysteine 6.47(257)-ligand interaction affording megagonist receptor activation. J Proteome Res 2011; 10:4789-98. [PMID: 21861534 DOI: 10.1021/pr2005583] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The lack of experimental characterization of the structures and ligand-binding motifs of therapeutic G-protein coupled receptors (GPCRs) hampers rational drug discovery. The human cannabinoid receptor 2 (hCB2R) is a class-A GPCR and promising therapeutic target for small-molecule cannabinergic agonists as medicines. Prior mutational and modeling data constitute provisional evidence that AM-841, a high-affinity classical cannabinoid, interacts with cysteine C6.47(257) in hCB2R transmembrane helix 6 (TMH6) to afford improved hCB2R selectivity and unprecedented agonist potency. We now apply bottom-up mass spectrometry (MS)-based proteomics to define directly the hCB2R-AM-841 interaction at the amino-acid level. Recombinant hCB2R, overexpressed as an N-terminal FLAG-tagged/C-terminal 6His-tagged protein (FLAG-hCB2R-6His) with a baculovirus system, was solubilized and purified by immunochromatography as functional receptor. A multiplex multiple reaction monitoring (MRM)-MS method was developed that allowed us to observe unambiguously all seven discrete TMH peptides in the tryptic digest of purified FLAG-hCB2R-6His and demonstrate that AM-841 modifies hCB2R TMH6 exclusively. High-resolution mass spectra of the TMH6 tryptic peptide obtained by Q-TOF MS/MS analysis demonstrated that AM-841 covalently and selectively modifies hCB2R at TMH6 cysteine C6.47(257). These data demonstrate how integration of MS-based proteomics into a ligand-assisted protein structure (LAPS) experimental paradigm can offer guidance to structure-enabled GPCR agonist design.
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Affiliation(s)
- Dennis W Szymanski
- Center for Drug Discovery, Department of Chemistry and Chemical Biology, College of Science, Northeastern University , Boston, Massachusetts 02115-5000, United States
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Panavas T, Lu J, Liu X, Winkis AM, Powers G, Naso MF, Amegadzie B. Generation and evaluation of mammalian secreted and membrane protein expression libraries for high-throughput target discovery. Protein Expr Purif 2011; 79:7-15. [DOI: 10.1016/j.pep.2011.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/12/2011] [Accepted: 05/18/2011] [Indexed: 11/16/2022]
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Kang C, Li Q. Solution NMR study of integral membrane proteins. Curr Opin Chem Biol 2011; 15:560-9. [DOI: 10.1016/j.cbpa.2011.05.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 05/12/2011] [Accepted: 05/23/2011] [Indexed: 11/29/2022]
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Langelaan DN, Ngweniform P, Rainey JK. Biophysical characterization of G-protein coupled receptor-peptide ligand binding. Biochem Cell Biol 2011; 89:98-105. [PMID: 21455262 DOI: 10.1139/o10-142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
G-protein coupled receptors (GPCRs) are ubiquitous membrane proteins allowing intracellular responses to extracellular factors that range from photons of light to small molecules to proteins. Despite extensive exploitation of GPCRs as therapeutic targets, biophysical characterization of GPCR-ligand interactions remains challenging. In this minireview, we focus on techniques that have been successfully used for structural and biophysical characterization of peptide ligands binding to their cognate GPCRs. The techniques reviewed include solution-state nuclear magnetic resonance (NMR) spectroscopy, solid-state NMR, X-ray diffraction, fluorescence spectroscopy and single-molecule fluorescence methods, flow cytometry, surface plasmon resonance, isothermal titration calorimetry, and atomic force microscopy. The goal herein is to provide a cohesive starting point to allow selection of techniques appropriate to the elucidation of a given GPCR-peptide interaction.
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Affiliation(s)
- David N Langelaan
- Department of Biochemistry & Molecular Biology, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada
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16
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Fan Y, Shi L, Ladizhansky V, Brown LS. Uniform isotope labeling of a eukaryotic seven-transmembrane helical protein in yeast enables high-resolution solid-state NMR studies in the lipid environment. JOURNAL OF BIOMOLECULAR NMR 2011; 49:151-161. [PMID: 21246256 DOI: 10.1007/s10858-011-9473-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 01/07/2011] [Indexed: 05/30/2023]
Abstract
Overexpression of isotope-labeled multi-spanning eukaryotic membrane proteins for structural NMR studies is often challenging. On the one hand, difficulties with achieving proper folding, membrane insertion, and native-like post-translational modifications frequently disqualify bacterial expression systems. On the other hand, eukaryotic cell cultures can be prohibitively expensive. One of the viable alternatives, successfully used for producing proteins for solution NMR studies, is yeast expression systems, particularly Pichia pastoris. We report on successful implementation and optimization of isotope labeling protocols, previously used for soluble secreted proteins, to produce homogeneous samples of a eukaryotic seven-transmembrane helical protein, rhodopsin from Leptosphaeria maculans. Even in shake-flask cultures, yields exceeded 5 mg of purified uniformly (13)C,(15)N-labeled protein per liter of culture. The protein was stable (at least several weeks at 5°C) and functionally active upon reconstitution into lipid membranes at high protein-to-lipid ratio required for solid-state NMR. The samples gave high-resolution (13)C and (15)N solid-state magic angle spinning NMR spectra, amenable to a detailed structural analysis. We believe that similar protocols can be adopted for challenging mammalian targets, which often resist characterization by other structural methods.
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Affiliation(s)
- Ying Fan
- Department of Physics, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
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19
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Abstract
G protein-coupled receptors (GPCRs) comprise a large class of transmembrane proteins that play critical roles in both normal physiology and pathophysiology. These critical roles offer targets for therapeutic intervention, as exemplified by the substantial fraction of current pharmaceutical agents that target members of this family. Tremendous contributions to our understanding of GPCR structure and dynamics have come from both indirect and direct structural characterization techniques. Key features of GPCR conformations derived from both types of characterization techniques are reviewed.
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Affiliation(s)
- Abby L. Parrill
- Department of Chemistry, The University of Memphis, Memphis, TN 38152, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-901-678-2638; Fax: +1-901-678-3447
| | - Debra L. Bautista
- Christian Brothers High School, 5900 Walnut Grove Road, Memphis, TN 38120, USA; E-Mail: (D.L.B.)
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Kobayashi NR, Hawes SM, Crook JM, Pébay A. G-protein coupled receptors in stem cell self-renewal and differentiation. Stem Cell Rev Rep 2010; 6:351-66. [PMID: 20625855 DOI: 10.1007/s12015-010-9167-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Stem cells have great potential for understanding early development, treating human disease, tissue trauma and early phase drug discovery. The factors that control the regulation of stem cell survival, proliferation, migration and differentiation are still emerging. Some evidence now exists demonstrating the potent effects of various G-protein coupled receptor (GPCR) ligands on the biology of stem cells. This review aims to give an overview of the current knowledge of the regulation of embryonic and somatic stem cell maintenance and differentiation by GPCR ligands.
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Vilar S, Ferino G, Phatak SS, Berk B, Cavasotto CN, Costanzi S. Docking-based virtual screening for ligands of G protein-coupled receptors: not only crystal structures but also in silico models. J Mol Graph Model 2010; 29:614-23. [PMID: 21146435 DOI: 10.1016/j.jmgm.2010.11.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/28/2010] [Accepted: 11/09/2010] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors (GPCRs) regulate a wide range of physiological functions and hold great pharmaceutical interest. Using the β(2)-adrenergic receptor as a case study, this article explores the applicability of docking-based virtual screening to the discovery of GPCR ligands and defines methods intended to improve the screening performance. Our controlled computational experiments were performed on a compound dataset containing known agonists and blockers of the receptor as well as a large number of decoys. The screening based on the structure of the receptor crystallized in complex with its inverse agonist carazolol yielded excellent results, with a clearly delineated prioritization of ligands over decoys. Blockers generally were preferred over agonists; however, agonists were also well distinguished from decoys. A method was devised to increase the screening yields by generating an ensemble of alternative conformations of the receptor that accounts for its flexibility. Moreover, a method was devised to improve the retrieval of agonists, based on the optimization of the receptor around a known agonist. Finally, the applicability of docking-based virtual screening also to homology models endowed with different levels of accuracy was proved. This last point is of uttermost importance, since crystal structures are available only for a limited number of GPCRs, and extends our conclusions to the entire superfamily. The outcome of this analysis definitely supports the application of computer-aided techniques to the discovery of novel GPCR ligands, especially in light of the fact that, in the near future, experimental structures are expected to be solved and become available for an ever increasing number of GPCRs.
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Affiliation(s)
- Santiago Vilar
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, MD 20892, USA
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