51
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Hulme EC, Lu ZL, Bee MS. Scanning Mutagenesis Studies of the M 1 Muscarinic Acetylcholine Receptor. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10606820308261] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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52
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Shenker A. Activating Mutations of the Lutropin Choriogonadotropin Receptor in Precocious Puberty. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10606820212138] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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53
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Dilly S, Scuvée-Moreau J, Wouters J, Liégeois JF. The 5-HT1A Agonism Potential of Substituted Piperazine-Ethyl-Amide Derivatives Is Conserved in the Hexyl Homologues: Molecular Modeling and Pharmacological Evaluation. J Chem Inf Model 2011; 51:2961-6. [DOI: 10.1021/ci200313r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Johan Wouters
- Department of Chemistry, University of Namur, rue de Bruxelles, 61, B-5000 Namur, Belgium
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54
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Shahlaei M, Madadkar-Sobhani A, Fassihi A, Saghaie L. Exploring a Model of a Chemokine Receptor/Ligand Complex in an Explicit Membrane Environment by Molecular Dynamics Simulation: The Human CCR1 Receptor. J Chem Inf Model 2011; 51:2717-30. [DOI: 10.1021/ci200261f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohsen Shahlaei
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, 81746-73461, Isfahan, Iran
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Armin Madadkar-Sobhani
- Department of Life Sciences, Barcelona Supercomputing Center, C\ Jordi Girona 31, Edificio Nexus II, 08028 Barcelona, Spain
- Department of Bioinformatics, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Afshin Fassihi
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, 81746-73461, Isfahan, Iran
| | - Lotfollah Saghaie
- Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, 81746-73461, Isfahan, Iran
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55
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Affiliation(s)
- Charles M. Marson
- Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H OAJ, United Kingdom
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56
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Zare B, Madadkar-Sobhani A, Dastmalchi S, Mahmoudian M. Prediction of the Human EP1 Receptor Binding Site by Homology Modeling and Molecular Dynamics Simulation. Sci Pharm 2011; 79:793-816. [PMID: 22145106 PMCID: PMC3221501 DOI: 10.3797/scipharm.1106-24] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/07/2011] [Indexed: 12/12/2022] Open
Abstract
The prostanoid receptor EP1 is a G-protein-coupled receptor (GPCR) known to be involved in a variety of pathological disorders such as pain, fever and inflammation. These receptors are important drug targets, but design of subtype specific agonists and antagonists has been partially hampered by the absence of three-dimensional structures for these receptors. To understand the molecular interactions of the PGE2, an endogen ligand, with the EP1 receptor, a homology model of the human EP1 receptor (hEP1R) with all connecting loops was constructed from the 2.6 Å resolution crystal structure (PDB code: 1L9H) of bovine rhodopsin. The initial model generated by MODELLER was subjected to molecular dynamics simulation to assess quality of the model. Also, a step by step ligand-supported model refinement was performed, including initial docking of PGE2 and iloprost in the putative binding site, followed by several rounds of energy minimizations and molecular dynamics simulations. Docking studies were performed for PGE2 and some other related compounds in the active site of the final hEP1 receptor model. The docking enabled us to identify key molecular interactions supported by the mutagenesis data. Also, the correlation of r2=0.81 was observed between the Ki values and the docking scores of 15 prostanoid compounds. The results obtained in this study may provide new insights toward understanding the active site conformation of the hEP1 receptor and can be used for the structure-based design of novel specific ligands.
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Affiliation(s)
- Behnoush Zare
- Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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57
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Ostopovici-Halip L, Curpăn R, Mracec M, Bologa CG. Structural determinants of the alpha2 adrenoceptor subtype selectivity. J Mol Graph Model 2011; 29:1030-8. [PMID: 21602069 PMCID: PMC3307019 DOI: 10.1016/j.jmgm.2011.04.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 04/26/2011] [Accepted: 04/27/2011] [Indexed: 11/18/2022]
Abstract
Alpha2-adrenergic receptor (α2-AR) subtypes, acting mainly on the central nervous and cardiovascular systems, represent important targets for drug design, confirmed by the high number of studies published so far. Presently, only a few α2-AR subtype selective compounds are known. Using homology modeling and ligand docking, the present study analyzes the similarities and differences between binding sites, and between extracellular loops of the three subtypes of α2-ARs. Several α2-AR subtype selective ligands were docked into the active sites of the three α2-AR subtypes, key interactions between ligands and receptors were mapped, and the predicted results were compared with the available experimental data. Binding site analysis reveals a strong identity between important amino acid residues in each receptor, the very few differences being the key toward modulating selectivity of α2-AR ligands. The observed differences between binding site residues provide an excellent starting point for virtual screening of chemical databases, in order to identify potentially selective ligands for α2-ARs.
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Affiliation(s)
- Liliana Ostopovici-Halip
- Computational Chemistry Department, Institute of Chemistry Timisoara, M. Viteazu 24, 300223, Romania.
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58
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Shim JY, Rudd J, Ding TT. Distinct second extracellular loop structures of the brain cannabinoid CB(1) receptor: implication in ligand binding and receptor function. Proteins 2011; 79:581-97. [PMID: 21120862 DOI: 10.1002/prot.22907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The G-protein-coupled receptor (GPCR) second extracellular loop (E2) is known to play an important role in receptor structure and function. The brain cannabinoid (CB(1)) receptor is unique in that it lacks the interloop E2 disulfide linkage to the transmembrane (TM) helical bundle, a characteristic of many GPCRs. Recent mutation studies of the CB(1) receptor, however, suggest the presence of an alternative intraloop disulfide bond between two E2 Cys residues. Considering the oxidation state of these Cys residues, we determine the molecular structures of the 17-residue E2 in the dithiol form (E2(dithiol)) and in the disulfide form (E2(disulfide)) of the CB(1) receptor in a fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer, using a combination of simulated annealing and molecular dynamics simulation approaches. We characterize the CB(1) receptor models with these two E2 forms, CB(1)(E2(dithiol)) and CB(1)(E2(disulfide)), by analyzing interaction energy, contact number, core crevice, and cross correlation. The results show that the distinct E2 structures interact differently with the TM helical bundle and uniquely modify the TM helical topology, suggesting that E2 of the CB(1) receptor plays a critical role in stabilizing receptor structure, regulating ligand binding, and ultimately modulating receptor activation. Further studies on the role of E2 of the CB(1) receptor are warranted, particularly comparisons of the ligand-bound form with the present ligand-free form.
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Affiliation(s)
- Joong-Youn Shim
- JL Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina 27707, USA.
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59
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Shim JY. Understanding functional residues of the cannabinoid CB1. Curr Top Med Chem 2011; 10:779-98. [PMID: 20370713 DOI: 10.2174/156802610791164210] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 10/27/2009] [Indexed: 02/07/2023]
Abstract
The brain cannabinoid (CB(1)) receptor that mediates numerous physiological processes in response to marijuana and other psychoactive compounds is a G protein coupled receptor (GPCR) and shares common structural features with many rhodopsin class GPCRs. For the rational development of therapeutic agents targeting the CB(1) receptor, understanding of the ligand-specific CB(1) receptor interactions responsible for unique G protein signals is crucial. For a more than a decade, a combination of mutagenesis and computational modeling approaches has been successfully employed to study the ligand-specific CB(1) receptor interactions. In this review, after a brief discussion about recent advances in understanding of some structural and functional features of GPCRs commonly applicable to the CB(1) receptor, the CB(1) receptor functional residues reported from mutational studies are divided into three different types, ligand binding (B), receptor stabilization (S) and receptor activation (A) residues, to delineate the nature of the binding pockets of anandamide, CP55940, WIN55212-2 and SR141716A and to describe the molecular events of the ligand-specific CB(1) receptor activation from ligand binding to G protein signaling. Taken these CB(1) receptor functional residues, some of which are unique to the CB(1) receptor, together with the biophysical knowledge accumulated for the GPCR active state, it is possible to propose the early stages of the CB(1) receptor activation process that not only provide some insights into understanding molecular mechanisms of receptor activation but also are applicable for identifying new therapeutic agents by applying the validated structure-based approaches, such as virtual high throughput screening (HTS) and fragment-based approach (FBA).
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Affiliation(s)
- Joong-Youn Shim
- J.L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA.
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60
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Rodríguez D, Piñeiro Á, Gutiérrez-de-Terán H. Molecular Dynamics Simulations Reveal Insights into Key Structural Elements of Adenosine Receptors. Biochemistry 2011; 50:4194-208. [DOI: 10.1021/bi200100t] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- David Rodríguez
- Fundación Pública Galega de Medicina Xenómica, Hospital Clínico Universitario de Santiago (CHUS), planta-2, A Choupana, s/n E-15706 Santiago de Compostela, Spain
| | - Ángel Piñeiro
- Soft Matter and Molecular Biophysics Group, Department of Applied Physics, University of Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain
| | - Hugo Gutiérrez-de-Terán
- Fundación Pública Galega de Medicina Xenómica, Hospital Clínico Universitario de Santiago (CHUS), planta-2, A Choupana, s/n E-15706 Santiago de Compostela, Spain
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61
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Rajamani R, Lin YL, Gao J. The opsin shift and mechanism of spectral tuning in rhodopsin. J Comput Chem 2011; 32:854-65. [PMID: 20941732 PMCID: PMC3021771 DOI: 10.1002/jcc.21663] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 08/07/2010] [Indexed: 01/12/2023]
Abstract
Molecular dynamics simulations and combined quantum mechanical and molecular mechanical calculations have been performed to investigate the mechanism of the opsin shift and spectral tuning in rhodopsin. A red shift of -980 cm(-1) was estimated in the transfer of the chromophore from methanol solution environment to the protonated Schiff base (PSB)-binding site of the opsin. The conformational change from a 6-s-cis-all-trans configuration in solution to the 6-s-cis-11-cis conformer contributes additional -200 cm(-1), and the remaining effects were attributed to dispersion interactions with the aromatic residues in the binding site. An opsin shift of 2100 cm(-1) was obtained, in reasonable accord with experiment (2730 cm(-1)). Dynamics simulations revealed that the 6-s-cis bond can occupy two main conformations for the β-ionone ring, resulting in a weighted average dihedral angle of about -50°, which may be compared with the experimental estimate of -28° from solid-state NMR and Raman data. We investigated a series of four single mutations, including E113D, A292S, T118A, and A269T, which are located near the PSB, along the polyene chain of retinal and close to the ionone ring. The computational results on absorption energy shift provided insights into the mechanism of spectral tuning, which involves all means of electronic structural effects, including the stabilization or destabilization of either the ground or the electronically excited state of the retinal PSB.
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Affiliation(s)
| | - Yen-lin Lin
- Department of Chemistry, Digital Technology Center, and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455
| | - Jiali Gao
- Department of Chemistry, Digital Technology Center, and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455
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62
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Diaz C, Leplatois P, Angelloz-Nicoud P, Lecomte M, Josse A, Delpech M, Pecceu F, Loison G, Shire D, Pascal M, Ferrara P, Ferran E. Differential Virtual Screening (DVS) with Active and Inactive Molecular Models for Finding and Profiling GPCR Modulators: Case of the CCK1 Receptor. Mol Inform 2011; 30:345-58. [DOI: 10.1002/minf.201000180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 02/23/2011] [Indexed: 11/10/2022]
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63
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Pabuwal V, Li Z. Comparison analysis of primary ligand-binding sites in seven-helix membrane proteins. Biopolymers 2011; 95:31-8. [PMID: 20672377 DOI: 10.1002/bip.21528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Seven-helix transmembrane proteins, including the G-protein-coupled receptors (GPCRs), mediate a broad range of fundamental cellular activities through binding to a wide range of ligands. Understanding the structural basis for the ligand-binding selectivity of these proteins is of significance to their structure-based drug design. Comparison analysis of proteins' ligand-binding sites provides a useful way to study their structure-activity relationships. Various computational methods have been developed for the binding-site comparison of soluble proteins. In this work, we applied this approach to the analysis of the primary ligand-binding sites of 92 seven-helix transmembrane proteins. Results of the studies confirmed that the binding site of bacterial rhodopsins is indeed different from all GPCRs. In the latter group, further comparison of the binding sites indicated a group of residues that could be responsible for ligand-binding selectivity and important for structure-based drug design. Furthermore, unexpected binding-site dissimilarities were observed among adrenergic and adenosine receptors, suggesting that the percentage of the overall sequence identity between a target protein and a template protein alone is not sufficient for selecting the best template for homology modeling of seven-helix membrane proteins. These results provided novel insight into the structural basis of ligand-binding selectivity of seven-helix membrane proteins and are of practical use to the computational modeling of these proteins.
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Affiliation(s)
- Vagmita Pabuwal
- Department of Chemistry and Biochemistry, University of the Sciences in Philadelphia, Philadelphia, PA 19104, USA
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64
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Abstract
Angiotensin converting enzyme (ACE) inhibitors are widely used for treatment of cardiovascular diseases. The effects of ACE inhibitors on the human bradykinin receptors were investigated. The mode of action of ACE inhibitors is considered. There is evidence that ACE inhibitors exert effects on the vascular system that cannot be attributed simply to the inhibition of ACE activity and accumulation of locally produced bradykinin. ACE inhibitors augment bradykinin effects on receptors indirectly by inducing cross-talk between ACE and the B2 receptor when enzyme and receptor molecules are sterically close, possibly forming a heterodimer. ACE inhibitors activate B1 receptors directly and independently of ACE via the zink-binding consensus sequence HEXXH, which is present in B1, but not in B2 receptor. Particular structure of B2 and B1 are represented, as well as receptor amino acids coupled with the G-proteins. Activation of kinin receptors by ACE inhibitors leads to clinically beneficial effects of ACE inhibitors.
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Affiliation(s)
- E.V. Kugaevskaya
- Institute of Biomedical Chemistry, Russian Academy of Medical Sciences (RAMS)
| | - Yu.E. Elisseeva
- Institute of Biomedical Chemistry, Russian Academy of Medical Sciences (RAMS)
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65
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Dilly S, Liégeois JF. Interaction of clozapine and its nitrenium ion with rat D2 dopamine receptors: in vitro binding and computational study. J Comput Aided Mol Des 2010; 25:163-9. [PMID: 21184252 DOI: 10.1007/s10822-010-9407-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 12/08/2010] [Indexed: 11/29/2022]
Abstract
The interaction of diazepine analogues like clozapine or olanzapine with D2 receptor was greatly affected by a mixture of HRP/H(2)O(2) known to induce the formation of nitrenium ion. Unlike diazepine derivatives, the oxidative mixture had low impact on the affinity of oxa- and thiazepine derivatives such as loxapine, clothiapine or JL13 for the D2 receptor. Molecular docking simulations revealed a huge difference between the mode of interaction of clozapine nitrenium ion and the parent drug. Electronic and geometric changes of the tricyclic ring system caused by the oxidation appeared to prevent the compound finding the correct binding mode and could therefore explain the difference observed in binding affinities.
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Affiliation(s)
- Sébastien Dilly
- Laboratory of Medicinal Chemistry and CIRM (B36), University of Liège, 4000 Liège, Belgium
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66
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Shahlaei M, Madadkar-Sobhani A, Mahnam K, Fassihi A, Saghaie L, Mansourian M. Homology modeling of human CCR5 and analysis of its binding properties through molecular docking and molecular dynamics simulation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:802-17. [PMID: 21167131 DOI: 10.1016/j.bbamem.2010.12.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/23/2010] [Accepted: 12/06/2010] [Indexed: 11/18/2022]
Abstract
In this study, homology modeling, molecular docking and molecular dynamics simulation were performed to explore structural features and binding mechanism of some inhibitors of chemokine receptor type 5 (CCR5), and to construct a model for designing new CCR5 inhibitors for preventing HIV attachment to the host cell. A homology modeling procedure was employed to construct a 3D model of CCR5. For this procedure, the X-ray crystal structure of bovine rhodopsin (1F88A) at 2.80Å resolution was used as template. After inserting the constructed model into a hydrated lipid bilayer, a 20ns molecular dynamics (MD) simulation was performed on the whole system. After reaching the equilibrium, twenty-four CCR5 inhibitors were docked in the active site of the obtained model. The binding models of the investigated antagonists indicate the mechanism of binding of the studied compounds to the CCR5 obviously. Moreover, 3D pictures of inhibitor-protein complex provided precious data regarding the binding orientation of each antagonist into the active site of this protein. One additional 20 ns MD simulation was performed on the initial structure of the CCR5-ligand 21 complex, resulted from the previous docking calculations, embedded in a hydrated POPE bilayer to explore the effects of the presence of lipid bilayer in the vicinity of CCR5-ligand complex. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.
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Affiliation(s)
- Mohsen Shahlaei
- Department of Medicinal Chemistry, School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
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67
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Scrima M, Di Marino S, Grimaldi M, Mastrogiacomo A, Novellino E, Bifulco M, D'Ursi AM. Binding of the hemopressin peptide to the cannabinoid CB1 receptor: structural insights. Biochemistry 2010; 49:10449-57. [PMID: 21062041 DOI: 10.1021/bi1011833] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hemopressin, a bioactive nonapeptide derived from the α1 chain of hemoglobin, was recently shown to possess selective antagonist activity at the cannabinoid CB(1) receptor [Heimann, A. S., et al. (2007) Proc. Natl. Acad. Sci. U.S.A. 104, 20588-20593]. CB(1) receptor antagonists have been extensively studied for their possible therapeutic use in the treatment of obesity, drug abuse, and heroin addiction. In particular, many compounds acting as CB(1) receptor antagonists have been synthesized and subjected to experiments as possible anti-obesity drugs, but their therapeutic application is still complicated by important side effects. Using circular dichroism and nuclear magnetic resonance spectroscopy, this work reports the conformational analysis of hemopressin and its truncated, biologically active fragment hemopressin(1-6). The binding modes of both hemopressin and hemopressin(1-6) are investigated by molecular docking calculations. Our conformational data indicate that regular turn structures in the central portion of hemopressin and hemopressin(1-6) are critical for an effective interaction with the receptor. The results of molecular docking calculations, indicating similarities and differences in comparison to the most accepted CB(1) pharmacophore model, suggest the possibility of new chemical scaffolds for the design of new CB(1) antagonist lead compounds.
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Affiliation(s)
- Mario Scrima
- Department of Pharmaceutical Sciences, University of Salerno, I-84084 Fisciano, Italy
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68
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López L, Selent J, Ortega R, Masaguer CF, Domínguez E, Areias F, Brea J, Loza MI, Sanz F, Pastor M. Synthesis, 3D-QSAR, and structural modeling of benzolactam derivatives with binding affinity for the D(2) and D(3) receptors. ChemMedChem 2010; 5:1300-17. [PMID: 20544783 DOI: 10.1002/cmdc.201000101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A series of 37 benzolactam derivatives were synthesized, and their respective affinities for the dopamine D(2) and D(3) receptors evaluated. The relationships between structures and binding affinities were investigated using both ligand-based (3D-QSAR) and receptor-based methods. The results revealed the importance of diverse structural features in explaining the differences in the observed affinities, such as the location of the benzolactam carbonyl oxygen, or the overall length of the compounds. The optimal values for such ligand properties are slightly different for the D(2) and D(3) receptors, even though the binding sites present a very high degree of homology. We explain these differences by the presence of a hydrogen bond network in the D(2) receptor which is absent in the D(3) receptor and limits the dimensions of the binding pocket, causing residues in helix 7 to become less accessible. The implications of these results for the design of more potent and selective benzolactam derivatives are presented and discussed.
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Affiliation(s)
- Laura López
- GRIB, IMIM, DCEXS, Universitat Pompeu Fabra, Barcelona, Spain
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69
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Smith TH, Sim-Selley LJ, Selley DE. Cannabinoid CB1 receptor-interacting proteins: novel targets for central nervous system drug discovery? Br J Pharmacol 2010; 160:454-66. [PMID: 20590557 DOI: 10.1111/j.1476-5381.2010.00777.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The main pharmacological effects of marijuana, as well as synthetic and endogenous cannabinoids, are mediated through G-protein-coupled receptors (GPCRs), including CB(1) and CB(2) receptors. The CB(1) receptor is the major cannabinoid receptor in the central nervous system and has gained increasing interest as a target for drug discovery for treatment of nausea, cachexia, obesity, pain, spasticity, neurodegenerative diseases and mood and substance abuse disorders. Evidence has accumulated to suggest that CB(1) receptors, like other GPCRs, interact with and are regulated by several other proteins beyond the established role of heterotrimeric G-proteins. These proteins, which include the GPCR kinases, beta-arrestins, GPCR-associated sorting proteins, factor associated with neutral sphingomyelinase, other GPCRs (heterodimerization) and the novel cannabinoid receptor-interacting proteins: CRIP(1a/b), are thought to play important roles in the regulation of intracellular trafficking, desensitization, down-regulation, signal transduction and constitutive activity of CB(1) receptors. This review examines CB(1) receptor-interacting proteins, including heterotrimeric G-proteins, but with particular emphasis on non-G-protein entities, that might comprise the CB(1) receptosomal complex. The evidence for direct interaction with CB(1) receptors and potential functional roles of these interacting proteins is discussed, as are future directions and challenges in this field with an emphasis on the possibility of eventually targeting these proteins for drug discovery.
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Affiliation(s)
- Tricia H Smith
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, School of Medicine, MCV Campus, Richmond, VA 23298-0524, USA
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70
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Ishikawa M, Watanabe T, Kudo T, Yokoyama F, Yamauchi M, Kato K, Kakui N, Sato Y. Investigation of the Histamine H3 Receptor Binding Site. Design and Synthesis of Hybrid Agonists with a Lipophilic Side Chain. J Med Chem 2010; 53:6445-56. [DOI: 10.1021/jm100643t] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Makoto Ishikawa
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Takashi Watanabe
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Toshiaki Kudo
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Fumikazu Yokoyama
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Miki Yamauchi
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Kazuhiko Kato
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Nobukazu Kakui
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
| | - Yasuo Sato
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
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71
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Michino M, Chen J, Stevens RC, Brooks CL. FoldGPCR: structure prediction protocol for the transmembrane domain of G protein-coupled receptors from class A. Proteins 2010; 78:2189-201. [PMID: 20544957 PMCID: PMC2933064 DOI: 10.1002/prot.22731] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Building reliable structural models of G protein-coupled receptors (GPCRs) is a difficult task because of the paucity of suitable templates, low sequence identity, and the wide variety of ligand specificities within the superfamily. Template-based modeling is known to be the most successful method for protein structure prediction. However, refinement of homology models within 1-3 A C alpha RMSD of the native structure remains a major challenge. Here, we address this problem by developing a novel protocol (foldGPCR) for modeling the transmembrane (TM) region of GPCRs in complex with a ligand, aimed to accurately model the structural divergence between the template and target in the TM helices. The protocol is based on predicted conserved inter-residue contacts between the template and target, and exploits an all-atom implicit membrane force field. The placement of the ligand in the binding pocket is guided by biochemical data. The foldGPCR protocol is implemented by a stepwise hierarchical approach, in which the TM helical bundle and the ligand are assembled by simulated annealing trials in the first step, and the receptor-ligand complex is refined with replica exchange sampling in the second step. The protocol is applied to model the human beta(2)-adrenergic receptor (beta(2)AR) bound to carazolol, using contacts derived from the template structure of bovine rhodopsin. Comparison with the X-ray crystal structure of the beta(2)AR shows that our protocol is particularly successful in accurately capturing helix backbone irregularities and helix-helix packing interactions that distinguish rhodopsin from beta(2)AR.
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Affiliation(s)
- Mayako Michino
- Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA 92037
| | - Jianhan Chen
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506
| | - Raymond C. Stevens
- Departments of Molecular Biology and Chemistry, The Scripps Research Institute, La Jolla, CA 92037
| | - Charles L. Brooks
- Department of Chemistry and Biophysics Program, University of Michigan, 930 N University Ave, Ann Arbor, MI 48109
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72
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Duportets L, Barrozo RB, Bozzolan F, Gaertner C, Anton S, Gadenne C, Debernard S. Cloning of an octopamine/tyramine receptor and plasticity of its expression as a function of adult sexual maturation in the male moth Agrotis ipsilon. INSECT MOLECULAR BIOLOGY 2010; 19:489-499. [PMID: 20491982 DOI: 10.1111/j.1365-2583.2010.01009.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In the male moth Agrotis ipsilon behavioural response and antennal lobe (AL) neuron sensitivity to the female-produced sex pheromone increase with age and juvenile hormone (JH) level. We recently showed that the neuromodulator, octopamine (OA), interacts with JH in this age-dependent olfactory plasticity. To further elucidate its role, we cloned a full cDNA encoding a protein that presents biochemical features essential to OA/tyramine receptor (AipsOAR/TAR) function. The AipsOAR/TAR transcript was detected predominantly in the antennae, the brain and, more specifically, in ALs where its expression level varied concomitantly with age. This expression plasticity indicates that AipsOAR/TAR might be involved in central processing of the pheromone signal during maturation of sexual behaviour in A. ipsilon.
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Affiliation(s)
- L Duportets
- UMR 1272, UPMC-INRA, Physiologie de l'Insecte: Signalisation et Communication, Université Paris VI, Bât A, 7 quai Saint Bernard, Paris, France
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73
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Gregory KJ, Dong EN, Meiler J, Conn PJ. Allosteric modulation of metabotropic glutamate receptors: structural insights and therapeutic potential. Neuropharmacology 2010; 60:66-81. [PMID: 20637216 DOI: 10.1016/j.neuropharm.2010.07.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/28/2010] [Accepted: 07/06/2010] [Indexed: 10/19/2022]
Abstract
Allosteric modulation of G protein-coupled receptors (GPCRs) represents a novel approach to the development of probes and therapeutics that is expected to enable subtype-specific regulation of central nervous system target receptors. The metabotropic glutamate receptors (mGlus) are class C GPCRs that play important neuromodulatory roles throughout the brain, as such they are attractive targets for therapeutic intervention for a number of psychiatric and neurological disorders including anxiety, depression, Fragile X Syndrome, Parkinson's disease and schizophrenia. Over the last fifteen years, selective allosteric modulators have been identified for many members of the mGlu family. The vast majority of these allosteric modulators are thought to bind within the transmembrane-spanning domains of the receptors to enhance or inhibit functional responses. A combination of mutagenesis-based studies and pharmacological approaches are beginning to provide a better understanding of mGlu allosteric sites. Collectively, when mapped onto a homology model of the different mGlu subtypes based on the β(2)-adrenergic receptor, the previous mutagenesis studies suggest commonalities in the location of allosteric sites across different members of the mGlu family. In addition, there is evidence for multiple allosteric binding pockets within the transmembrane region that can interact to modulate one another. In the absence of a class C GPCR crystal structure, this approach has shown promise with respect to the interpretation of mutagenesis data and understanding structure-activity relationships of allosteric modulator pharmacophores.
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Affiliation(s)
- Karen J Gregory
- Department of Pharmacology, Vanderbilt Program in Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232-0697, USA.
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74
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Pecic S, Makkar P, Chaudhary S, Reddy BV, Navarro HA, Harding WW. Affinity of aporphines for the human 5-HT2A receptor: insights from homology modeling and molecular docking studies. Bioorg Med Chem 2010; 18:5562-75. [PMID: 20621490 DOI: 10.1016/j.bmc.2010.06.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/08/2010] [Accepted: 06/14/2010] [Indexed: 11/29/2022]
Abstract
Analogs of nantenine were docked into a modeled structure of the human 5-HT(2A) receptor using ICM Pro, GLIDE, and GOLD docking methods. The resultant docking scores were used to correlate with observed in vitro apparent affinity (K(e)) data. The GOLD docking algorithm when used with a homology model of 5-HT(2A), based on a bovine rhodopsin template and built by the program MODELLER, gives results which are most in agreement with the in vitro results. Further analysis of the docking poses among members of a C1 alkyl series of nantenine analogs, indicate that they bind to the receptor in a similar orientation, but differently than nantenine. Besides an important interaction between the protonated nitrogen of the C1 alkyl analogs and residue Asp155, we identified Ser242, Phe234, and Gly238 as key residues responsible for the affinity of these compounds for the 5-HT(2A) receptor. Specifically, the ability of some of these analogs to establish a H-bond with Ser242 and hydrophobic interactions with Phe234 and Gly238 appears to explain their enhanced affinity as compared to nantenine.
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Affiliation(s)
- Stevan Pecic
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
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75
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Hong WX, Baker KA, Ma X, Stevens RC, Yeager M, Zhang Q. Design, synthesis, and properties of branch-chained maltoside detergents for stabilization and crystallization of integral membrane proteins: human connexin 26. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8690-6. [PMID: 20232919 PMCID: PMC2877156 DOI: 10.1021/la904893d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A challenging requirement for structural studies of integral membrane proteins (IMPs) is the use of amphiphiles that replicate the hydrophobic environment of membranes. Progress has been impeded by the limited number of useful detergents and the need for a deeper understanding of their structure-activity relationships. To this end, we designed a family of detergents containing short, branched alkyl chains at the interface between the polar head and the apolar tail. This design mimics the second aliphatic chain of lipid molecules and reduces water penetration, thereby increasing the hydrophobicity within the interior of the micelle. To compare with the popular straight-chained maltoside detergents, the branch-chained beta-D-maltosides were synthesized efficiently in pure anomeric form. The branch-chained maltosides form smaller micelles by having shorter main chains, while having comparable hydrophobicity to the detergents with only straight chains. Selected branch-chained and straight-chained maltoside detergents were examined for their ability to solubilize, stabilize, and aid the crystallization of human connexin 26, an alpha-helical IMP that forms hexamers. We showed that the branch-chained maltosides with optimized micellar properties performed as well as or better than the straight-chained analogues and enabled crystallization in different space groups.
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Affiliation(s)
- Wen-Xu Hong
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Kent A. Baker
- Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Xingquan Ma
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Raymond C. Stevens
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Mark Yeager
- Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22906
| | - Qinghai Zhang
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
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76
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C(alpha)-trace model of the transmembrane domain of human copper transporter 1, motion and functional implications. Proc Natl Acad Sci U S A 2010; 107:10908-13. [PMID: 20534491 DOI: 10.1073/pnas.0914717107] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The trimeric human copper transporter 1 (hCTR1) is essential for copper uptake and is implicated in sensitivity to chemotherapy drugs. Using the cryoelectron microscopy (cryoEM) map of hCTR1 and evolutionary data, we constructed a Calpha-trace model of the membrane region. The model structure, supported by mutagenesis data, was used to investigate global dynamics through elastic network models. Identified as dominant hinge regions, hCTR1's MxxxM and GxxxG motifs were shown to have significant roles in functional movements characterized by the two slowest modes of motion. Both modes predicted significant changes at the wide cytoplasmic pore region; the slowest mode introduced a rotational motion around the pore central axis, whereas in the following mode the cytoplasmic parts of the helices approached and moved away from the pore center. In the most cooperative mode, the MxxxM motif in the extracellular narrow region remained static. The second mode of motion, however, predicted a cooperative rotational motion of this copper-binding motif, possibly reflecting activation at the pore's extracellular entrance. We suggest a molecular mechanism of copper transport in which this motif serves both as a gate and as a selectivity filter. We also suggest residues that are responsible for pH activation.
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77
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Dawadi PBS, Lugtenburg J. Synthesis and use of stable isotope enriched retinals in the field of vitamin A. Molecules 2010; 15:1825-72. [PMID: 20336016 PMCID: PMC6257204 DOI: 10.3390/molecules15031825] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 02/18/2010] [Accepted: 03/02/2010] [Indexed: 01/05/2023] Open
Abstract
The role of vitamin A and its metabolites in the life processes starting with the historical background and its up to date information is discussed in the introduction. Also the role of 11Z-retinal in vision and retinoic acid in the biological processes is elucidated. The essential role of isotopically enriched systems in the progress of vision research, nutrition research etc. is discussed. In part B industrial commercial syntheses of vitamin A by the two leading companies Hoffmann-La Roche (now DSM) and BASF are discussed. The knowledge obtained via these pioneering syntheses has been essential for the further synthetic efforts in vitamin A field by other scientific groups. The rest of the paper is devoted to the synthetic efforts of the Leiden group that gives an access to the preparation of site directed high level isotope enrichment in retinals. First the synthesis of the retinals with deuterium incorporation in the conjugated side chain is reviewed. Then, 13C-labeled retinals are discussed. This is followed by the discussion of a convergent synthetic scheme that allows a rational access to prepare any isotopomer of retinals. The schemes that provide access to prepare any possible isotope enriched chemically modified systems are discussed. Finally, nor-retinals and bridged retinals that give access to a whole (as yet incomplete) library of possible isotopomers are reviewed.
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Affiliation(s)
- Prativa B S Dawadi
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
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78
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Chugunov AO, Efremov RG. [Prediction of the spatial structure of proteins: emphasis on membrane targets]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 35:744-60. [PMID: 20208575 DOI: 10.1134/s106816200906003x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knowledge of the spatial structure of proteins is a prerequisite for both awareness of their functional mechanisms and the framework for rational drug discovery and design. Meanwhile, direct structural determination is often hampered or impractical due to the complexity, expensiveness, and limited capabilities of experimental techniques. These issues are especially pronounced for integral membrane proteins. On numerous occasions, the theoretical prediction of protein structures may facilitate the process by exploiting physical or empirical principles. This paper surveys modern techniques for the prediction of the spatial structure of proteins using computer algorithms, and the main emphasis is placed on the most "complex" targets - membrane proteins (MPs). The first part of the review describes de novo methods based on empirical physical principles; in the second part, a comparative modeling philosophy, which accounts for the structure of related proteins, is described. Special focus is made regarding pharmacologically relevant classes of G-coupled receptors, receptor tyrosine ki-nases, and other MPs. Algorithms for the assessment of the models quality and potential fields of application of computer models are discussed.
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79
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Varin T, Gutiérrez-de-Terán H, Castro M, Brea J, Fabis F, Dauphin F, Åqvist J, Lepailleur A, Perez P, Burgueño J, Vela JM, Loza MI, Rodrigo J. Phe369(7.38) at human 5-HT(7) receptors confers interspecies selectivity to antagonists and partial agonists. Br J Pharmacol 2010; 159:1069-81. [PMID: 19922537 PMCID: PMC2839265 DOI: 10.1111/j.1476-5381.2009.00481.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 07/22/2009] [Accepted: 07/31/2009] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Human and rat 5-HT(7) receptors were studied with a particular emphasis on the molecular interactions involved in ligand binding, searching for an explanation to the interspecies selectivity observed for a set of compounds. We performed affinity studies, molecular modelling and site-directed mutagenesis, with special focus on residue Phe(7.38) of the human 5-HT(7) receptor [Cys(7.38) in rat]. EXPERIMENTAL APPROACH Competition binding studies were performed for seven 5-HT(7) receptor ligands at three different 5-HT(7) receptors. The functional behaviour was evaluated by measuring 5-carboxytryptamine-stimulated cAMP production. Computational simulations were carried out to explore the structural bases in ligand binding observed for these compounds. KEY RESULTS Competition experiments showed a remarkable selectivity for the human receptor when compared with the rat receptor. These results indicate that mutating Cys to Phe at position 7.38 profoundly affects the binding affinities at the 5-HT(7) receptor. Computational simulations provide a structural interpretation for this key finding. Pharmacological characterization of compounds mr25020, mr25040 and mr25053 revealed a competitive antagonistic behaviour. Compounds mr22423, mr22433, mr23284 and mr25052 behaved as partial agonists. CONCLUSIONS AND IMPLICATIONS We propose that the interspecies difference in binding affinities observed for the compounds at human and rat 5-HT(7) receptors is due to the nature of the residue at position 7.38. Our molecular modelling simulations suggest that Phe(7.38) in the human receptor is integrated in the hydrophobic pocket in the central part of the binding site [Phe(6.51)-Phe(6.52)] and allows a tighter binding of the ligands when compared with the rat receptor.
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Affiliation(s)
- Thibault Varin
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Hugo Gutiérrez-de-Terán
- Fundación Pública Galega de Medicina Xenómica, Hospital Clínico Universitario de SantiagoSantiago de Compostela, Spain
| | - Marián Castro
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - José Brea
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - Frederic Fabis
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - François Dauphin
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Johan Åqvist
- Department of Cell and Molecular Biology, Uppsala UniversityUppsala, Sweden
| | - Alban Lepailleur
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Pilar Perez
- Department of Pharmacology, Laboratorios EsteveBarcelona, Spain
| | - Javier Burgueño
- Department of Pharmacology, Laboratorios EsteveBarcelona, Spain
| | | | - Maria Isabel Loza
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - Jordi Rodrigo
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
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80
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Varela Lopez O, Alvarez Vazquez JC, Gonzalez Cantalapiedra A, Rosolen SG. Effects of hypercapnia on the electroretinogram in sevoflurane and isoflurane anaesthetized dogs. Doc Ophthalmol 2010; 121:9-20. [DOI: 10.1007/s10633-010-9223-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 02/01/2010] [Indexed: 10/19/2022]
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81
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Etchebest C, Debret G. Critical review of general guidelines for membrane proteins model building and analysis. Methods Mol Biol 2010; 654:363-385. [PMID: 20665276 DOI: 10.1007/978-1-60761-762-4_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Membrane proteins play major roles in many biological processes such as signalling, transport, etc. They have been shown to be involved in the development of many diseases and have become important drug targets per se. The understanding of their functional properties may be facilitated if a 3D structure is available. However, in the case of membrane proteins, only a few 3D structures have been solved to date. Bioinformatics and molecular modelling approaches are thus powerful alternatives to fill the gap between the sequence and the structure. Here, a review of the most recent approaches is proposed together with guidelines on how to use them. In addition, insofar as important biological processes require conformational changes, we discuss some interesting methods aimed at exploring the dynamic behaviour of proteins in their membrane environment. The paper ends with a brief description of useful approaches for determining oligomerisation or ligand binding sites.
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Affiliation(s)
- Catherine Etchebest
- INSERM UMR-S 665, Equipe Dynamique des Structures et des Interactions des Macromolécules Biologiques (DSIMB), Institut National de Transfusion Sanguine (INTS), Université Paris Diderot - Paris 7, Paris, France.
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82
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Eudes A, Kunji ERS, Noiriel A, Klaus SMJ, Vickers TJ, Beverley SM, Gregory JF, Hanson AD. Identification of transport-critical residues in a folate transporter from the folate-biopterin transporter (FBT) family. J Biol Chem 2009; 285:2867-75. [PMID: 19923217 DOI: 10.1074/jbc.m109.063651] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Synechocystis Slr0642 protein and its plastidial Arabidopsis (Arabidopsis thaliana) ortholog At2g32040 belong to the folate-biopterin transporter (FBT) family within the major facilitator superfamily. Both proteins transport folates when expressed in Escherichia coli. Because the structural requirements for transport activity are not known for any FBT protein, we applied mutational analysis to identify residues that are critical to transport and interpreted the results using a comparative structural model based on E. coli lactose permease. Folate transport was assessed via the growth of an E. coli pabA abgT strain, which cannot synthesize or take up folates or p-aminobenzoylglutamate. In total, 47 residues were replaced with Cys or Ala. Mutations at 22 positions abolished folate uptake without affecting Slr0642 expression in membranes, whereas other mutations had no effect. Residues important for function mostly line the predicted central cavity and are concentrated in the core alpha-helices H1, H4, H7, and H10. The essential residue locations are consistent with a folate-binding site lying roughly equidistant from both faces of the transporter. Arabidopsis has eight FBT proteins besides At2g32040, often lacking conserved critical residues. When six of these proteins were expressed in E. coli or in Leishmania folate or pterin transporter mutants, none showed evidence of folate or pterin transport activity, and only At2g32040 was isolated by functional screening of Arabidopsis cDNA libraries in E. coli. Such negative data could reflect roles in transport of other substrates. These studies provide the first insights into the native structure and catalytic mechanism of FBT family carriers.
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Affiliation(s)
- Aymerick Eudes
- Horticultural Sciences, Human Nutrition Department, University of Florida, Gainesville, Florida 32611, USA
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83
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Cogé F, Guenin SP, Fery I, Migaud M, Devavry S, Slugocki C, Legros C, Ouvry C, Cohen W, Renault N, Nosjean O, Malpaux B, Delagrange P, Boutin JA. The end of a myth: cloning and characterization of the ovine melatonin MT(2) receptor. Br J Pharmacol 2009; 158:1248-62. [PMID: 19814723 DOI: 10.1111/j.1476-5381.2009.00453.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE For many years, it was suspected that sheep expressed only one melatonin receptor (closely resembling MT(1) from other mammal species). Here we report the cloning of another melatonin receptor, MT(2), from sheep. EXPERIMENTAL APPROACH Using a thermo-resistant reverse transcriptase and polymerase chain reaction primer set homologous to the bovine MT(2) mRNA sequence, we have cloned and characterized MT(2) receptors from sheep retina. KEY RESULTS The ovine MT(2) receptor presents 96%, 72% and 67% identity with cattle, human and rat respectively. This MT(2) receptor stably expressed in CHO-K1 cells showed high-affinity 2[(125)I]-iodomelatonin binding (K(D)= 0.04 nM). The rank order of inhibition of 2[(125)I]-iodomelatonin binding by melatonin, 4-phenyl-2-propionamidotetralin and luzindole was similar to that exhibited by MT(2) receptors of other species (melatonin > 4-phenyl-2-propionamidotetralin > luzindole). However, its pharmacological profile was closer to that of rat, rather than human MT(2) receptors. Functionally, the ovine MT(2) receptors were coupled to G(i) proteins leading to inhibition of adenylyl cyclase, as the other melatonin receptors. In sheep brain, MT(2) mRNA was expressed in pars tuberalis, choroid plexus and retina, and moderately in mammillary bodies. Real-time polymerase chain reaction showed that in sheep pars tuberalis, premammillary hypothalamus and mammillary bodies, the temporal pattern of expression of MT(1) and MT(2) mRNA was not parallel in the three tissues. CONCLUSION AND IMPLICATIONS Co-expression of MT(1) and MT(2) receptors in all analysed sheep brain tissues suggests that MT(2) receptors may participate in melatonin regulation of seasonal anovulatory activity in ewes by modulating MT(1) receptor action.
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Affiliation(s)
- F Cogé
- Pharmacologie Moléculaire et Cellulaire, Institut de Recherches SERVIER, Suresnes, France
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84
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Rai BK, Tawa GJ, Katz AH, Humblet C. Modeling G protein-coupled receptors for structure-based drug discovery using low-frequency normal modes for refinement of homology models: Application to H3 antagonists. Proteins 2009; 78:457-73. [DOI: 10.1002/prot.22571] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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85
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Harrington SE, Ben-Tal N. Structural Determinants of Transmembrane Helical Proteins. Structure 2009; 17:1092-103. [DOI: 10.1016/j.str.2009.06.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 06/15/2009] [Accepted: 06/16/2009] [Indexed: 12/16/2022]
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86
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Ehrlich K, Götz A, Bollinger S, Tschammer N, Bettinetti L, Härterich S, Hübner H, Lanig H, Gmeiner P. Dopamine D2, D3, and D4 Selective Phenylpiperazines as Molecular Probes To Explore the Origins of Subtype Specific Receptor Binding. J Med Chem 2009; 52:4923-35. [DOI: 10.1021/jm900690y] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katharina Ehrlich
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Angela Götz
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
- Department of Chemistry and Pharmacy, Computer Chemistry Center, Friedrich-Alexander-Universität, Nägelsbachstrasse, 25, 91052 Erlangen, Germany
| | - Stefan Bollinger
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Nuska Tschammer
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Laura Bettinetti
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Steffen Härterich
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
| | - Harald Lanig
- Department of Chemistry and Pharmacy, Computer Chemistry Center, Friedrich-Alexander-Universität, Nägelsbachstrasse, 25, 91052 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University, Schuhstrasse 19, 91052 Erlangen, Germany
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87
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Transmembrane helical domain of the cannabinoid CB1 receptor. Biophys J 2009; 96:3251-62. [PMID: 19383469 DOI: 10.1016/j.bpj.2008.12.3934] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 12/09/2008] [Accepted: 12/30/2008] [Indexed: 01/05/2023] Open
Abstract
Brain cannabinoid (CB(1)) receptors are G-protein coupled receptors and belong to the rhodopsin-like subfamily. A homology model of the inactive state of the CB(1) receptor was constructed using the x-ray structure of beta(2)-adrenergic receptor (beta(2)AR) as the template. We used 105 ns duration molecular-dynamics simulations of the CB(1) receptor embedded in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer to gain some insight into the structure and function of the CB(1) receptor. As judged from the root mean-square deviations combined with the detailed structural analyses, the helical bundle of the CB(1) receptor appears to be fully converged in 50 ns of the simulation. The results reveal that the helical bundle structure of the CB(1) receptor maintains a topology quite similar to the x-ray structures of G-protein coupled receptors overall. It is also revealed that the CB(1) receptor is stabilized by the formation of extensive, water-mediated H-bond networks, aromatic stacking interactions, and receptor-lipid interactions within the helical core region. It is likely that these interactions, which are often specific to functional motifs, including the S(N)LAxAD, D(E)RY, CWxP, and NPxxY motifs, are the molecular constraints imposed on the inactive state of the CB(1) receptor. It appears that disruption of these specific interactions is necessary to release the molecular constraints to achieve a conformational change of the receptor suitable for G-protein activation.
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88
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New vistas in GPCR 3D structure prediction. J Mol Model 2009; 16:183-91. [PMID: 19551412 DOI: 10.1007/s00894-009-0533-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 05/06/2009] [Indexed: 10/20/2022]
Abstract
Human G-protein coupled receptors (hGPCRs) comprise the most prominent family of validated drug targets. More than 50% of approved drugs reveal their therapeutic effects by targeting this family. Accurate models would greatly facilitate the process of drug discovery and development. However, 3-D structure prediction of GPCRs remains a challenge due to limited availability of resolved structure. The X-ray structures have been solved for only four such proteins. The identity between hGPCRs and the potential templates is mostly less than 30%, well below the level at which sequence alignment can be done regularly. In this study, we analyze a large database of human G-protein coupled receptors that are members of family A in order to optimize usage of the available crystal structures for molecular modeling of hGPCRs. On the basis of our findings in this study, we propose to regard specific parts from the trans-membrane domains of the reference receptor helices as appropriate template for constructing models of other GPCRs, while other residues require other techniques for their remodeling and refinement. The proposed hypothesis in the current study has been tested by modeling human beta2-adrenergic receptor based on crystal structures of bovine rhodopsin (1F88) and human A2A adenosine receptor (3EML). The results have shown some improvement in the quality of the predicted models compared to Modeller software.
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89
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Huynh J, Thomas WG, Aguilar MI, Pattenden LK. Role of helix 8 in G protein-coupled receptors based on structure-function studies on the type 1 angiotensin receptor. Mol Cell Endocrinol 2009; 302:118-27. [PMID: 19418628 DOI: 10.1016/j.mce.2009.01.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are transmembrane receptors that convert extracellular stimuli to intracellular signals. The type 1 angiotensin II receptor is a widely studied GPCR with roles in blood pressure regulation,water and salt balance and cell growth. The complex molecular and structural changes that underpin receptor activation and signaling are the focus of intense research. Increasingly, there is an appreciation that the plasma membrane participates in receptor function via direct, physical interactions that reciprocally modulate both lipid and receptor and provide microdomains for specialized activities. Reversible protein:lipid interactions are commonly mediated by amphipathic -helices in proteins and one such motif - a short helix, referred to as helix VIII/8 (H8), located at the start of the carboxyl (C)-terminus of GPCRs - is gaining recognition for its importance to GPCR function. Here, we review the identification of H8 in GPCRs and examine its capacity to sense and interact with diverse proteins and lipid environment, most notably with acidic lipids that include phosphatidylinositol phosphates.
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MESH Headings
- Binding Sites
- Humans
- Lipids/chemistry
- Protein Binding
- Protein Structure, Secondary
- Receptor, Angiotensin, Type 1/chemistry
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 1/physiology
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Signal Transduction
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Affiliation(s)
- John Huynh
- School of Biomedical Sciences, The University of Queensland, Brisbane, St Lucia, Queensland, Australia
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90
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Liu X, Kai M, Jin L, Wang R. Computational study of the heterodimerization between mu and delta receptors. J Comput Aided Mol Des 2009; 23:321-32. [PMID: 19214754 DOI: 10.1007/s10822-009-9262-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Accepted: 01/18/2009] [Indexed: 11/27/2022]
Abstract
A growing body of evidence indicated that the G protein coupled receptors exist as homo- or hetero-dimers in the living cell. The heterodimerization between mu and delta opioid receptors has attracted researchers' particular interests, it is reported to display novel pharmacological and signalling regulation properties. In this study, we construct the full-length 3D-model of mu and delta opioid receptors using the homology modelling method. Threading program was used to predict the possible templates for the N- and C-terminus domains. Then, a 30 ns molecular dynamics simulations was performed with each receptor embedded in an explicit membrane-water environment to refine and explore the conformational space. Based on the structures extracted from the molecular dynamics, the likely interface of mu-delta heterodimer was investigated through the analysis of protein-protein docking, cluster, shape complementary and interaction energy. The computational modelling works revealed that the most likely interface of heterodimer was formed between the transmembrane1,7 (TM1,7) domains of mu receptor and the TM(4,5) domains of delta receptor, with emphasis on mu-TM1 and delta-TM4, the next likely interface was mu(TM6,7)-delta(TM4,5), with emphasis on mu-TM6 and delta-TM4. Our results were consistent with previous reports.
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Affiliation(s)
- Xin Liu
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Science, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, China
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91
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Yuzlenko O, Kieć-Kononowicz K. Molecular modeling of A1 and A2A adenosine receptors: comparison of rhodopsin- and beta2-adrenergic-based homology models through the docking studies. J Comput Chem 2008; 30:14-32. [PMID: 18496794 DOI: 10.1002/jcc.21001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Adenosine receptors (ARs) are members of the superfamily of G protein-coupled receptors. The homology models of adenosine A1 and A2A receptors were constructed. The high-resolution X-ray structure of bovine rhodopsin and crystal structure of beta2-adrenergic receptor were used as templates. The binding sites of the A1 and A2A ARs were constructed by using data obtained from mutagenesis experiments as well as docking simulations of the respective AR antagonsists DPCPX and XAC. To compare rhodopsin- and beta2-adrenergic-based models, the binding mode of A1 (KW-3902, LUF-5437) and A2A (KW-6002, ZM-241385) ARs antagonists were also examined. The differences in the binding ability of both models were noted during the study. The beta2-adrenergic-based A2A AR model was much more capable to stabilize the ligand in the binding site cavity than the corresponding rhodopsin-based A2A AR model, however, such differences were not so clear in case of A1 AR models. It was suggested that for the A1 AR it is possible to use the crystal structure of rhodopsin as a template as well as beta2-adrenergic receptor, but for A2A AR, with the now available beta2-adrenergic receptor X-ray structure, docking studies should be avoided on the rhodopsin-based model. However, taking into account that the beta2AR shares about 31% of the residues with the AR in comparison to 21% in case of bRho, we suggest using beta2-adrenergic-based models for the A1 and A2A ARs for further in silico ligand screening also because of their generally better ability to stabilize ligands inside the binding pocket.
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Affiliation(s)
- Olga Yuzlenko
- Department of Technology and Biotechnology of Drugs, Medical College, Jagiellonian University, Kraków, Poland
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92
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Runyon SP, Mosier PD, Roth BL, Glennon RA, Westkaemper RB. Potential modes of interaction of 9-aminomethyl-9,10-dihydroanthracene (AMDA) derivatives with the 5-HT2A receptor: a ligand structure-affinity relationship, receptor mutagenesis and receptor modeling investigation. J Med Chem 2008; 51:6808-28. [PMID: 18847250 DOI: 10.1021/jm800771x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of 3-position substitution of 9-aminomethyl-9,10-dihydroanthracene (AMDA) on 5-HT 2A receptor affinity were determined and compared to a parallel series of DOB-like 1-(2,5-dimethoxyphenyl)-2-aminopropanes substituted at the 4-position. The results were interpreted within the context of 5-HT 2A receptor models that suggest that members of the DOB-like series can bind to the receptor in two distinct modes that correlate with the compounds' functional activity. Automated ligand docking and molecular dynamics suggest that all of the AMDA derivatives, the parent of which is a 5-HT 2A antagonist, bind in a fashion analogous to that for the sterically demanding antagonist DOB-like compounds. The failure of the F340 (6.52)L mutation to adversely affect the affinity of AMDA and the 3-bromo derivative is consistent with the proposed modes of orientation. Evaluation of ligand-receptor complex models suggest that a valine/threonine exchange between the 5-HT 2A and D 2 receptors may be the origin of selectivity for AMDA and two substituted derivatives.
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Affiliation(s)
- Scott P Runyon
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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93
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Härterich S, Koschatzky S, Einsiedel J, Gmeiner P. Novel insights into GPCR—Peptide interactions: Mutations in extracellular loop 1, ligand backbone methylations and molecular modeling of neurotensin receptor 1. Bioorg Med Chem 2008; 16:9359-68. [DOI: 10.1016/j.bmc.2008.08.051] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Accepted: 08/22/2008] [Indexed: 11/24/2022]
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94
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Aranda R, Villalba K, Raviña E, Masaguer CF, Brea J, Areias F, Domínguez E, Selent J, López L, Sanz F, Pastor M, Loza MI. Synthesis, Binding Affinity, and Molecular Docking Analysis of New Benzofuranone Derivatives as Potential Antipsychotics. J Med Chem 2008; 51:6085-94. [DOI: 10.1021/jm800602w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Reyes Aranda
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Karen Villalba
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Enrique Raviña
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Christian F. Masaguer
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - José Brea
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Filipe Areias
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Eduardo Domínguez
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Jana Selent
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Laura López
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Ferran Sanz
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Manuel Pastor
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - María I. Loza
- Departamento de Química Orgánica, Laboratorio de Química Farmacéutica, and Departamento de Farmacología, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain, and Research Unit on Biomedical Informatics (GRIB), IMIM, Universitat Pompeu Fabra, Dr. Aiguader 88, E-08003 Barcelona, Spain
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95
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Artigas RA, Gonzalez A, Riquelme E, Carvajal CA, Cattani A, Martínez-Aguayo A, Kalergis AM, Pérez-Acle T, Fardella CE. A novel adrenocorticotropin receptor mutation alters its structure and function, causing familial glucocorticoid deficiency. J Clin Endocrinol Metab 2008; 93:3097-105. [PMID: 18492762 DOI: 10.1210/jc.2008-0048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
CONTEXT Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by unresponsiveness to ACTH. In this study, two mutations of the ACTH receptor (MC2R) gene are reported in this FGD clinical case. OBJECTIVE The objective of the study was to characterize a novel MC2R gene mutation in a compound heterozygous patient with FGD phenotype. DESIGN This was a clinical case description, biochemical, molecular, and bioinformatics analysis to describe a novel MC2R gene mutation. PATIENTS The subject of the study was a male diagnosed with primary adrenal insufficiency. The family history showed nonconsanguineous healthy parents, three healthy siblings, and one brother affected with FGD. MAIN OUTCOME MEASURES The mutant MC2R-Ala126Ser showed significantly lower activity when it was stimulated with ACTH-(1-24) than did cells transfected with wild-type MC2R. RESULTS The molecular studies demonstrated the presence of an adenine heterozygous insertion (InsA1347) in the MC2R gene (G217fs) in the patient. This insertion was due to a frame shift mutation in one allele and a premature stop codon codifying an aberrant receptor of 247 residues (27.2 kDa). We also found a novel heterozygous mutation alanine 126 by serine. Molecular dynamic simulations showed that serine 126 side chain fluctuates forming a noncanonical intrahelical hydrogen bond in the transmembrane helix 3 of the mutated receptor. This produces a structural rearrangement of the MC2R internal cavities that may affect the ligand recognition and signal transduction throughout the G protein. CONCLUSIONS We propose a molecular explanation for the reduced activity exhibited by the MC2R alanine 126 by serine mutant.
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Affiliation(s)
- Rocío A Artigas
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Lira 85, 5 degrees piso, 8330074 Santiago, Chile
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96
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Warne T, Serrano-Vega MJ, Baker JG, Moukhametzianov R, Edwards PC, Henderson R, Leslie AG, Tate CG, Schertler GF. Structure of a beta1-adrenergic G-protein-coupled receptor. Nature 2008; 454:486-91. [PMID: 18594507 PMCID: PMC2923055 DOI: 10.1038/nature07101] [Citation(s) in RCA: 1188] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 05/19/2008] [Indexed: 11/09/2022]
Abstract
G-protein-coupled receptors have a major role in transmembrane signalling in most eukaryotes and many are important drug targets. Here we report the 2.7 A resolution crystal structure of a beta(1)-adrenergic receptor in complex with the high-affinity antagonist cyanopindolol. The modified turkey (Meleagris gallopavo) receptor was selected to be in its antagonist conformation and its thermostability improved by earlier limited mutagenesis. The ligand-binding pocket comprises 15 side chains from amino acid residues in 4 transmembrane alpha-helices and extracellular loop 2. This loop defines the entrance of the ligand-binding pocket and is stabilized by two disulphide bonds and a sodium ion. Binding of cyanopindolol to the beta(1)-adrenergic receptor and binding of carazolol to the beta(2)-adrenergic receptor involve similar interactions. A short well-defined helix in cytoplasmic loop 2, not observed in either rhodopsin or the beta(2)-adrenergic receptor, directly interacts by means of a tyrosine with the highly conserved DRY motif at the end of helix 3 that is essential for receptor activation.
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Affiliation(s)
- Tony Warne
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | | | | | | | | | - Richard Henderson
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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97
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In silico identified CCR4 antagonists target regulatory T cells and exert adjuvant activity in vaccination. Proc Natl Acad Sci U S A 2008; 105:10221-6. [PMID: 18621704 DOI: 10.1073/pnas.0803453105] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Adjuvants are substances that enhance immune responses and thus improve the efficacy of vaccination. Few adjuvants are available for use in humans, and the one that is most commonly used (alum) often induces suboptimal immunity for protection against many pathogens. There is thus an obvious need to develop new and improved adjuvants. We have therefore taken an approach to adjuvant discovery that uses in silico modeling and structure-based drug-design. As proof-of-principle we chose to target the interaction of the chemokines CCL22 and CCL17 with their receptor CCR4. CCR4 was posited as an adjuvant target based on its expression on CD4(+)CD25(+) regulatory T cells (Tregs), which negatively regulate immune responses induced by dendritic cells (DC), whereas CCL17 and CCL22 are chemotactic agents produced by DC, which are crucial in promoting contact between DC and CCR4(+) T cells. Molecules identified by virtual screening and molecular docking as CCR4 antagonists were able to block CCL22- and CCL17-mediated recruitment of human Tregs and Th2 cells. Furthermore, CCR4 antagonists enhanced DC-mediated human CD4(+) T cell proliferation in an in vitro immune response model and amplified cellular and humoral immune responses in vivo in experimental models when injected in combination with either Modified Vaccinia Ankara expressing Ag85A from Mycobacterium tuberculosis (MVA85A) or recombinant hepatitis B virus surface antigen (rHBsAg) vaccines. The significant adjuvant activity observed provides good evidence supporting our hypothesis that CCR4 is a viable target for rational adjuvant design.
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98
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Langmead CJ, Austin NE, Branch CL, Brown JT, Buchanan KA, Davies CH, Forbes IT, Fry VAH, Hagan JJ, Herdon HJ, Jones GA, Jeggo R, Kew JNC, Mazzali A, Melarange R, Patel N, Pardoe J, Randall AD, Roberts C, Roopun A, Starr KR, Teriakidis A, Wood MD, Whittington M, Wu Z, Watson J. Characterization of a CNS penetrant, selective M1 muscarinic receptor agonist, 77-LH-28-1. Br J Pharmacol 2008; 154:1104-15. [PMID: 18454168 DOI: 10.1038/bjp.2008.152] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE M1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype-selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh-binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC-42 (4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine), which bind to an allosteric site and selectively activate the M(1) mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. EXPERIMENTAL APPROACH In this study, we have compared the pharmacological profile of AC-42 and a close structural analogue, 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. KEY RESULTS Calcium mobilization and inositol phosphate accumulation assays revealed that both AC-42 and 77-LH-28-1 display high selectivity to activate the M1 mAChR over other mAChR subtypes. Furthermore, 77-LH-28-1, but not AC-42, acted as an agonist at rat hippocampal M1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77-LH-28-1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. CONCLUSIONS AND IMPLICATIONS These data suggest that 77-LH-28-1 is a potent, selective, bioavailable and brain-penetrant agonist at the M1 mAChR and therefore that it represents a better tool than AC-42, with which to study the pharmacology of the M1 mAChR.
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Affiliation(s)
- C J Langmead
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, Essex, UK.
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99
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Dastmalchi S, Church WB, Morris MB. Modelling the structures of G protein-coupled receptors aided by three-dimensional validation. BMC Bioinformatics 2008; 9 Suppl 1:S14. [PMID: 18315845 PMCID: PMC2259415 DOI: 10.1186/1471-2105-9-s1-s14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background G protein-coupled receptors (GPCRs) are abundant, activate complex signalling and represent the targets for up to ~60% of pharmaceuticals but there is a paucity of structural data. Bovine rhodopsin is the first GPCR for which high-resolution structures have been completed but significant variations in structure are likely to exist among the GPCRs. Because of this, considerable effort has been expended on developing in silico tools for refining structures of individual GPCRs. We have developed REPIMPS, a modification of the inverse-folding software Profiles-3D, to assess and predict the rotational orientation and vertical position of helices within the helix bundle of individual GPCRs. We highlight the value of the method by applying it to the Baldwin GPCR template but the method can, in principle, be applied to any low- or high-resolution membrane protein template or structure. Results 3D models were built for transmembrane helical segments of 493 GPCRs based on the Baldwin template, and the models were then scored using REPIMPS and Profiles-3D. The compatibility scores increased significantly using REPIMPS because it takes into account the physicochemical properties of the (lipid) environment surrounding the helix bundle. The arrangement of helices in the helix bundle of the 493 models was then altered systematically by rotating the individual helices. For most GPCRs in the set, changes in the rotational position of one or more helices resulted in significant improvement in the compatibility scores. In particular, for most GPCRs, a rotation of helix VII by 240–300° resulted in improved scores. Bovine rhodopsin modelled using this method showed 3.31 Å RMSD to its crystal structure for 198 Cα atom pairs, suggesting the utility of the method even when starting with idealised structures such as the Baldwin template. Conclusion We have developed an in silico tool which can be used to test the validity of, and refine, models of GPCRs with respect to helix rotation and vertical position based on the physicochemical properties of amino acids and the surrounding environment. The method can be applied to any multi-pass membrane protein and potentially can be used in combination with other high-throughput methodologies to generate and refine models of membrane proteins.
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Affiliation(s)
- Siavoush Dastmalchi
- School of Pharmacy, Tabriz University of Medical Sciences, Tabriz 51664, Iran.
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100
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Bu L, Michino M, Wolf RM, Brooks CL. Improved model building and assessment of the Calcium-sensing receptor transmembrane domain. Proteins 2008; 71:215-26. [DOI: 10.1002/prot.21685] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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