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Takahashi T, Huang Y, Yamamoto K, Hamano G, Kakino A, Kang F, Imaizumi Y, Takeshita H, Nozato Y, Nozato S, Yokoyama S, Nagasawa M, Kawai T, Takeda M, Fujimoto T, Hongyo K, Nakagami F, Akasaka H, Takami Y, Takeya Y, Sugimoto K, Gaisano HY, Sawamura T, Rakugi H. The endocytosis of oxidized LDL via the activation of the angiotensin II type 1 receptor. iScience 2021; 24:102076. [PMID: 33659870 PMCID: PMC7890409 DOI: 10.1016/j.isci.2021.102076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 12/06/2020] [Accepted: 01/14/2021] [Indexed: 01/14/2023] Open
Abstract
Arrestin-dependent activation of a G-protein-coupled receptor (GPCR) triggers endocytotic internalization of the receptor complex. We analyzed the interaction between the pattern recognition receptor (PRR) lectin-like oxidized low-density lipoprotein (oxLDL) receptor (LOX-1) and the GPCR angiotensin II type 1 receptor (AT1) to report a hitherto unidentified mechanism whereby internalization of the GPCR mediates cellular endocytosis of the PRR ligand. Using genetically modified Chinese hamster ovary cells, we found that oxLDL activates Gαi but not the Gαq pathway of AT1 in the presence of LOX-1. Endocytosis of the oxLDL-LOX-1 complex through the AT1-β-arrestin pathway was demonstrated by real-time imaging of the membrane dynamics of LOX-1 and visualization of endocytosis of oxLDL. Finally, this endocytotic pathway involving GPCR kinases (GRKs), β-arrestin, and clathrin is relevant in accumulating oxLDL in human vascular endothelial cells. Together, our findings indicate that oxLDL activates selective G proteins and β-arrestin-dependent internalization of AT1, whereby the oxLDL-LOX-1 complex undergoes endocytosis. The binding of oxidized LDL (oxLDL) to LOX-1 induces selective activation of AT1 oxLDL and angiotensin II additively or competitively activate AT1 in different cells oxLDL promotes β-arrestin-dependent internalization of oxLDL-LOX-1-AT1 complex
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Affiliation(s)
- Toshimasa Takahashi
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Department of Medicine, University of Toronto, Toronto, Ontario M5S1A8, Canada
| | - Yibin Huang
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Koichi Yamamoto
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Corresponding author
| | - Go Hamano
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Akemi Kakino
- Department of Molecular Pathophysiology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano 390-8621, Japan
| | - Fei Kang
- Department of Medicine, University of Toronto, Toronto, Ontario M5S1A8, Canada
| | - Yuki Imaizumi
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hikari Takeshita
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoichi Nozato
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Satoko Nozato
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Serina Yokoyama
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Motonori Nagasawa
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tatsuo Kawai
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Masao Takeda
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Taku Fujimoto
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kazuhiro Hongyo
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Futoshi Nakagami
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroshi Akasaka
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoichi Takami
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yasushi Takeya
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ken Sugimoto
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Herbert Y. Gaisano
- Department of Medicine, University of Toronto, Toronto, Ontario M5S1A8, Canada
| | - Tatsuya Sawamura
- Department of Molecular Pathophysiology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano 390-8621, Japan
| | - Hiromi Rakugi
- Department of Geriatric and General Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Anderson SD, Tabassum A, Yeon JK, Sharma G, Santos P, Soong TH, Thu YW, Nies I, Kurita T, Chandler A, Alsamarah A, Kanassatega RS, Luo YL, Botello-Smith WM, Andresen BT. In silico prediction of ARB resistance: A first step in creating personalized ARB therapy. PLoS Comput Biol 2020; 16:e1007719. [PMID: 33237899 PMCID: PMC7725353 DOI: 10.1371/journal.pcbi.1007719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 12/09/2020] [Accepted: 09/06/2020] [Indexed: 11/24/2022] Open
Abstract
Angiotensin II type 1 receptor (AT1R) blockers (ARBs) are among the most prescribed drugs. However, ARB effectiveness varies widely, which may be due to non-synonymous single nucleotide polymorphisms (nsSNPs) within the AT1R gene. The AT1R coding sequence contains over 100 nsSNPs; therefore, this study embarked on determining which nsSNPs may abrogate the binding of selective ARBs. The crystal structure of olmesartan-bound human AT1R (PDB:4ZUD) served as a template to create an inactive apo-AT1R via molecular dynamics simulation (n = 3). All simulations resulted in a water accessible ligand-binding pocket that lacked sodium ions. The model remained inactive displaying little movement in the receptor core; however, helix 8 showed considerable flexibility. A single frame representing the average stable AT1R was used as a template to dock Olmesartan via AutoDock 4.2, MOE, and AutoDock Vina to obtain predicted binding poses and mean Boltzmann weighted average affinity. The docking results did not match the known pose and affinity of Olmesartan. Thus, an optimization protocol was initiated using AutoDock 4.2 that provided more accurate poses and affinity for Olmesartan (n = 6). Atomic models of 103 of the known human AT1R polymorphisms were constructed using the molecular dynamics equilibrated apo-AT1R. Each of the eight ARBs was then docked, using ARB-optimized parameters, to each polymorphic AT1R (n = 6). Although each nsSNP has a negligible effect on the global AT1R structure, most nsSNPs drastically alter a sub-set of ARBs affinity to the AT1R. Alterations within N298 –L314 strongly effected predicted ARB affinity, which aligns with early mutagenesis studies. The current study demonstrates the potential of utilizing in silico approaches towards personalized ARB therapy. The results presented here will guide further biochemical studies and refinement of the model to increase the accuracy of the prediction of ARB resistance in order to increase overall ARB effectiveness. The term "personalized medicine" was coined at the turn of the century, but most medicines currently prescribed are based on disease categories and occasionally racial demographics, not personalized attributes. In cardiovascular medicine, the personalization of medication is minimal, despite the fact that not all patients respond equally to common cardiovascular medications. Here we chose one prominent cardiovascular drug target, the angiotensin receptor, and, using computer modeling, created preliminary models of over 100 known alterations to the angiotensin receptor to determine if the alterations changed the ability of clinically used drugs to interact with the angiotensin receptor. The strength of interaction was compared to the wild-type angiotensin receptor, generating a map predicting which alteration affected which drug(s). It is expected that in the future, sequencing of drug targets can be used to compare a patient’s result to a map similar to what is provided in this manuscript to choose the optimal medication based on the patient’s genetics. Such a process has the potential to facilitate the personalization of current medication therapy.
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Affiliation(s)
- Shane D. Anderson
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Asna Tabassum
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Jae Kyung Yeon
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Garima Sharma
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Priscilla Santos
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Tik Hang Soong
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Yin Win Thu
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Isaac Nies
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Tomomi Kurita
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Andrew Chandler
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Abdelaziz Alsamarah
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Rhye-Samuel Kanassatega
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
| | - Yun L. Luo
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
- * E-mail: (YLL); (WMB-S); (BTA)
| | - Wesley M. Botello-Smith
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
- * E-mail: (YLL); (WMB-S); (BTA)
| | - Bradley T. Andresen
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California, United States of America
- * E-mail: (YLL); (WMB-S); (BTA)
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Erol I, Cosut B, Durdagi S. Toward Understanding the Impact of Dimerization Interfaces in Angiotensin II Type 1 Receptor. J Chem Inf Model 2019; 59:4314-4327. [PMID: 31429557 DOI: 10.1021/acs.jcim.9b00294] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Angiotensin II type 1 receptor (AT1R) is a prototypical class A G protein-coupled receptor (GPCR) that has an important role in cardiovascular pathologies and blood pressure regulation as well as in the central nervous system. GPCRs may exist and function as monomers; however, they can assemble to form higher order structures, and as a result of oligomerization, their function and signaling profiles can be altered. In the case of AT1R, the classical Gαq/11 pathway is initiated with endogenous agonist angiotensin II binding. A variety of cardiovascular pathologies such as heart failure, diabetic nephropathy, atherosclerosis, and hypertension are associated with this pathway. Recent findings reveal that AT1R can form homodimers and activate the noncanonical (β-arrestin-mediated) pathway. Nevertheless, the exact dimerization interface and atomic details of AT1R homodimerization have not been still elucidated. Here, six different symmetrical dimer interfaces of AT1R are considered, and homodimers were constructed using other published GPCR crystal dimer interfaces as template structures. These AT1R homodimers were then inserted into the model membrane bilayers and subjected to all-atom molecular dynamics simulations. Our simulation results along with the principal component analysis and water pathway analysis suggest four different interfaces as the most plausible: symmetrical transmembrane (TM)1,2,8; TM5; TM4; and TM4,5 AT1R dimer interfaces that consist of one inactive and one active protomer. Moreover, we identified ILE2386.33 as a hub residue in the stabilization of the inactive state of AT1R.
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Affiliation(s)
- Ismail Erol
- Department of Chemistry , Gebze Technical University , Gebze 41400 , Kocaeli , Turkey
| | - Bunyemin Cosut
- Department of Chemistry , Gebze Technical University , Gebze 41400 , Kocaeli , Turkey
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Singh KD, Unal H, Desnoyer R, Karnik SS. Mechanism of Hormone Peptide Activation of a GPCR: Angiotensin II Activated State of AT 1R Initiated by van der Waals Attraction. J Chem Inf Model 2019; 59:373-385. [PMID: 30608150 DOI: 10.1021/acs.jcim.8b00583] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We present a succession of structural changes involved in hormone peptide activation of a prototypical GPCR. Microsecond molecular dynamics simulation generated conformational ensembles reveal propagation of structural changes through key "microswitches" within human AT1R bound to native hormone. The endocrine octa-peptide angiotensin II (AngII) activates AT1R signaling in our bodies which maintains physiological blood pressure, electrolyte balance, and cardiovascular homeostasis. Excessive AT1R activation is associated with pathogenesis of hypertension and cardiovascular diseases which are treated by sartan drugs. The mechanism of AT1R inhibition by sartans has been elucidated by 2.8 Å X-ray structures, mutagenesis, and computational analyses. Yet, the mechanism of AT1R activation by AngII is unclear. The current study delineates an activation scheme initiated by AngII binding. A van der Waals "grasp" interaction between Phe8AngII with Ile2887.39 in AT1R induced mechanical strain pulling Tyr2927.43 and breakage of critical interhelical H-bonds, first between Tyr2927.43 and Val1083.32 and second between Asn1113.35 and Asn2957.46. Subsequently changes are observed in conserved microswitches DRYTM3, Yx7K(R)TM5, CWxPTM6, and NPxxYTM7 in AT1R. Activating the microswitches in the intracellular region of AT1R may trigger formation of the G-protein binding pocket as well as exposure of helix-8 to cytoplasm. Thus, the active-like conformation of AT1R is initiated by the van der Waals interaction of Phe8AngII with Ile2887.39, followed by systematic reorganization of critical interhelical H-bonds and activation of microswitches.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , Ohio 44195 , United States
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Singh KD, Unal H, Desnoyer R, Karnik SS. Divergent Spatiotemporal Interaction of Angiotensin Receptor Blocking Drugs with Angiotensin Type 1 Receptor. J Chem Inf Model 2017; 58:182-193. [PMID: 29195045 DOI: 10.1021/acs.jcim.7b00424] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystal structures of the human angiotensin II type 1 receptor (AT1R) complex with the antihypertensive agent ZD7155 (PDB id: 4YAY ) and the blood pressure medication Benicar (PDB id: 4ZUD ) showed that binding poses of both antagonists are similar. This finding implies that clinically used angiotensin receptor blocking (ARB) drugs may interact in a similar fashion. However, clinically observed differences in pharmacological and therapeutic efficacies of ARBs lead to the question of whether the dynamic interactions of AT1R with ARBs vary. To address this, we performed induced-fit docking (IFD) of eight clinically used ARBs to AT1R followed by 200 ns molecular dynamic (MD) simulation. The experimental Ki values for ARBs correlated remarkably well with calculated free energy with R2 = 0.95 and 0.70 for AT1R-ARB models generated respectively by IFD and MD simulation. The eight ARB-AT1R complexes share a common set of binding residues. In addition, MD simulation results validated by mutagenesis data discovered distinctive spatiotemporal interactions that display unique bonding between an individual ARB and AT1R. These findings provide a reasonably broader picture reconciling the structure-based observations with clinical studies reporting efficacy variations for ARBs. The unique differences unraveled for ARBs in this study will be useful for structure-based design of the next generation of more potent and selective ARBs.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation , Cleveland, Ohio 44195, United States
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Jayakar SS, Ang G, Chiara DC, Hamouda AK. Photoaffinity Labeling of Pentameric Ligand-Gated Ion Channels: A Proteomic Approach to Identify Allosteric Modulator Binding Sites. Methods Mol Biol 2017; 1598:157-197. [PMID: 28508361 DOI: 10.1007/978-1-4939-6952-4_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Photoaffinity labeling techniques have been used for decades to identify drug binding sites and to study the structural biology of allosteric transitions in transmembrane proteins including pentameric ligand-gated ion channels (pLGIC). In a typical photoaffinity labeling experiment, to identify drug binding sites, UV light is used to introduce a covalent bond between a photoreactive ligand (which upon irradiation at the appropriate wavelength converts to a reactive intermediate) and amino acid residues that lie within its binding site. Then protein chemistry and peptide microsequencing techniques are used to identify these amino acids within the protein primary sequence. These amino acid residues are located within homology models of the receptor to identify the binding site of the photoreactive probe. Molecular modeling techniques are then used to model the binding of the photoreactive probe within the binding site using docking protocols. Photoaffinity labeling directly identifies amino acids that contribute to drug binding sites regardless of their location within the protein structure and distinguishes them from amino acids that are only involved in the transduction of the conformational changes mediated by the drug, but may not be part of its binding site (such as those identified by mutational studies). Major limitations of photoaffinity labeling include the availability of photoreactive ligands that faithfully mimic the properties of the parent molecule and protein preparations that supply large enough quantities suitable for photoaffinity labeling experiments. When the ligand of interest is not intrinsically photoreactive, chemical modifications to add a photoreactive group to the parent drug, and pharmacological evaluation of these chemical modifications become necessary. With few exceptions, expression and affinity-purification of proteins are required prior to photolabeling. Methods to isolate milligram quantities of highly enriched pLGIC suitable for photoaffinity labeling experiments have been developed. In this chapter, we discuss practical aspects of experimental strategies to identify allosteric modulator binding sites in pLGIC using photoaffinity labeling.
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Affiliation(s)
- Selwyn S Jayakar
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Gordon Ang
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, TX, USA
| | - David C Chiara
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Ayman K Hamouda
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, TX, USA. .,Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, TX, USA. .,Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Kingsville, TX, USA.
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Dormán G, Nakamura H, Pulsipher A, Prestwich GD. The Life of Pi Star: Exploring the Exciting and Forbidden Worlds of the Benzophenone Photophore. Chem Rev 2016; 116:15284-15398. [PMID: 27983805 DOI: 10.1021/acs.chemrev.6b00342] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The widespread applications of benzophenone (BP) photochemistry in biological chemistry, bioorganic chemistry, and material science have been prominent in both academic and industrial research. BP photophores have unique photochemical properties: upon n-π* excitation at 365 nm, a biradicaloid triplet state is formed reversibly, which can abstract a hydrogen atom from accessible C-H bonds; the radicals subsequently recombine, creating a stable covalent C-C bond. This light-directed covalent attachment process is exploited in many different ways: (i) binding/contact site mapping of ligand (or protein)-protein interactions; (ii) identification of molecular targets and interactome mapping; (iii) proteome profiling; (iv) bioconjugation and site-directed modification of biopolymers; (v) surface grafting and immobilization. BP photochemistry also has many practical advantages, including low reactivity toward water, stability in ambient light, and the convenient excitation at 365 nm. In addition, several BP-containing building blocks and reagents are commercially available. In this review, we explore the "forbidden" (transitions) and excitation-activated world of photoinduced covalent attachment of BP photophores by touring a colorful palette of recent examples. In this exploration, we will see the pros and cons of using BP photophores, and we hope that both novice and expert photolabelers will enjoy and be inspired by the breadth and depth of possibilities.
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Affiliation(s)
- György Dormán
- Targetex llc , Dunakeszi H-2120, Hungary.,Faculty of Pharmacy, University of Szeged , Szeged H-6720, Hungary
| | - Hiroyuki Nakamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology , Yokohama 226-8503, Japan
| | - Abigail Pulsipher
- GlycoMira Therapeutics, Inc. , Salt Lake City, Utah 84108, United States.,Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
| | - Glenn D Prestwich
- Division of Head and Neck Surgery, Rhinology - Sinus and Skull Base Surgery, Department of Surgery, University of Utah School of Medicine , Salt Lake City, Utah 84108, United States
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Han XF, He X, Wang M, Xu D, Hao LP, Liang AH, Zhang J, Zhou ZM. Discovery of novel, potent and low-toxicity angiotensin II receptor type 1 (AT1) blockers: Design, synthesis and biological evaluation of 6-substituted aminocarbonyl benzimidazoles with a chiral center. Eur J Med Chem 2015; 103:473-87. [DOI: 10.1016/j.ejmech.2015.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 07/28/2015] [Accepted: 09/06/2015] [Indexed: 10/23/2022]
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Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
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Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
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10
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Smajić M, Nikolić K, Vujić Z, Ahmetović L, Kuntić V. 3D-QSAR studies and pharmacophore identification of AT1 receptor antagonists. Med Chem Res 2015. [DOI: 10.1007/s00044-015-1470-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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11
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Cabana J, Holleran B, Leduc R, Escher E, Guillemette G, Lavigne P. Identification of Distinct Conformations of the Angiotensin-II Type 1 Receptor Associated with the Gq/11 Protein Pathway and the β-Arrestin Pathway Using Molecular Dynamics Simulations. J Biol Chem 2015; 290:15835-15854. [PMID: 25934394 DOI: 10.1074/jbc.m114.627356] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Indexed: 01/14/2023] Open
Abstract
Biased signaling represents the ability of G protein-coupled receptors to engage distinct pathways with various efficacies depending on the ligand used or on mutations in the receptor. The angiotensin-II type 1 (AT1) receptor, a prototypical class A G protein-coupled receptor, can activate various effectors upon stimulation with the endogenous ligand angiotensin-II (AngII), including the Gq/11 protein and β-arrestins. It is believed that the activation of those two pathways can be associated with distinct conformations of the AT1 receptor. To verify this hypothesis, microseconds of molecular dynamics simulations were computed to explore the conformational landscape sampled by the WT-AT1 receptor, the N111G-AT1 receptor (constitutively active and biased for the Gq/11 pathway), and the D74N-AT1 receptor (biased for the β-arrestin1 and -2 pathways) in their apo-forms and in complex with AngII. The molecular dynamics simulations of the AngII-WT-AT1, N111G-AT1, and AngII-N111G-AT1 receptors revealed specific structural rearrangements compared with the initial and ground state of the receptor. Simulations of the D74N-AT1 receptor revealed that the mutation stabilizes the receptor in the initial ground state. The presence of AngII further stabilized the ground state of the D74N-AT1 receptor. The biased agonist [Sar(1),Ile(8)]AngII also showed a preference for the ground state of the WT-AT1 receptor compared with AngII. These results suggest that activation of the Gq/11 pathway is associated with a specific conformational transition stabilized by the agonist, whereas the activation of the β-arrestin pathway is linked to the stabilization of the ground state of the receptor.
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Affiliation(s)
- Jérôme Cabana
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4; PROTEO (Quebec Network on Protein Structure, Function, and Engineering), Université Laval, Québec, Québec G1V 0A6, Canada
| | - Brian Holleran
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Richard Leduc
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Emanuel Escher
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Gaétan Guillemette
- Departments of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4
| | - Pierre Lavigne
- PROTEO (Quebec Network on Protein Structure, Function, and Engineering), Université Laval, Québec, Québec G1V 0A6, Canada; Biochemistry, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4.
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12
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Han XF, Xue WZ, Hao LP, Zhou ZM. Synthesis and biological evaluation of 4′-[(benzimidazol-1-yl) methyl]biphenyl-2-amides as dual angiotensin II and endothelin A receptor antagonists. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00169b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Discovery of new benzimidazoles as potent dual AT1 and ETA receptor antagonists with the novel N-(1H-tetrazol-5-yl)-amide fragment.
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Affiliation(s)
- Xiao-Feng Han
- R & D Center for Pharmaceticals
- Beijing Institute of Technology
- Beijing 100081
- PR China
| | - Wei-Zhe Xue
- R & D Center for Pharmaceticals
- Beijing Institute of Technology
- Beijing 100081
- PR China
| | - Li-Ping Hao
- R & D Center for Pharmaceticals
- Beijing Institute of Technology
- Beijing 100081
- PR China
| | - Zhi-Ming Zhou
- R & D Center for Pharmaceticals
- Beijing Institute of Technology
- Beijing 100081
- PR China
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13
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da C Silva D, Maltarollo VG, de Lima EF, Weber KC, Honorio KM. Understanding electrostatic and steric requirements related to hypertensive action of AT(1) antagonists using molecular modeling techniques. J Mol Model 2014; 20:2231. [PMID: 24935104 DOI: 10.1007/s00894-014-2231-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/02/2014] [Indexed: 12/01/2022]
Abstract
AT1 receptor is an interesting biological target involved in several important diseases, such as blood hypertension and cardiovascular pathologies. In this study we investigated the main electrostatic and steric features of a series of AT1 antagonists related to hypertensive activity using structure and ligand-based strategies (docking and CoMFA). The generated 3D model had good internal and external consistency and was used to predict the potency of an external test set. The predicted values of pIC50 are in good agreement with the experimental results of biological activity, indicating that the 3D model can be used to predict the biological property of untested compounds. The electrostatic and steric CoMFA maps showed molecular recognition patterns, which were analyzed with structure-based molecular modeling studies (docking). The most and the least potent compounds docked into the AT1 binding site were subjected to molecular dynamics simulations with the aim to verify the stability and the flexibility of the ligand-receptor interactions. These results provided valuable insights on the electronic/structural requirements to design novel AT1 antagonists.
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Affiliation(s)
- Danielle da C Silva
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, Brazil
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14
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Singh KD, Karthikeyan M. Combined sequence and sequence-structure-based methods for analyzing RAAS gene SNPs: a computational approach. J Recept Signal Transduct Res 2014; 34:513-26. [DOI: 10.3109/10799893.2014.922575] [Citation(s) in RCA: 7] [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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15
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Perols A, Karlström AE. Site-specific photoconjugation of antibodies using chemically synthesized IgG-binding domains. Bioconjug Chem 2014; 25:481-8. [PMID: 24520805 DOI: 10.1021/bc400440u] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Site-specific labeling of antibodies can be performed using the immunoglobulin-binding Z domain, derived from staphylococcal protein A (SpA), which has a well-characterized binding site in the Fc region of antibodies. By introducing a photoactivable probe in the Z domain, a covalent bond can be formed between the Z domain and the antibody by irradiation with UV light. The aim of this study was to improve the conjugation yield for labeling of different subclasses of IgG having different sequence composition, using a photoactivated Z domain variant. Four different variants of the Z domain (Z5BPA, Z5BBA, Z32BPA, and Z32BBA) were synthesized to investigate the influence of the position of the photoactivable probe and the presence of a flexible linker between the probe and the protein. For two of the variants, the photoreactive benzophenone group was introduced as part of an amino acid side chain by incorporation of the unnatural amino acid benzoylphenylalanine (BPA) during peptide synthesis. For the other two variants, the photoreactive benzophenone group was attached via a flexible linker by coupling of benzoylbenzoic acid (BBA) to the ε-amino group of a selectively deprotected lysine residue. Photoconjugation experiments using human IgG1, mouse IgG1, and mouse IgG2A demonstrated efficient conjugation for all antibodies. It was shown that differences in linker length had a large impact on the conjugation efficiency for labeling of mouse IgG1, whereas the positioning of the photoactivable probe in the sequence of the protein had a larger effect for mouse IgG2A. Conjugation to human IgG1 was only to a minor extent affected by position or linker length. For each subclass of antibody, the best variant tested using a standard conjugation protocol resulted in conjugation efficiencies of 41-66%, which corresponds to on average approximately one Z domain attached to each antibody. As a combination of the two best performing variants, Z5BBA and Z32BPA, a Z domain variant with two photoactivable probes (Z5BBA32BPA) was also synthesized with the aim of targeting a wider panel of antibody subclasses and species. This new reagent could efficiently couple to all antibody subclasses that were targeted by the single benzophenone-labeled Z domain variants, with conjugation efficiencies of 26-41%.
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Affiliation(s)
- Anna Perols
- KTH Royal Institute of Technology, School of Biotechnology, Division of Protein Technology, AlbaNova University Center , SE - 106 91 Stockholm, Sweden
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16
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Tomohiro T, Hatanaka Y. Diazirine-Based Multifunctional Photo-Probes for Affinity-Based Elucidation of Protein-Ligand Interaction. HETEROCYCLES 2014. [DOI: 10.3987/rev-14-803] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Singh KD, Muthusamy K. Molecular modeling, quantum polarized ligand docking and structure-based 3D-QSAR analysis of the imidazole series as dual AT(1) and ET(A) receptor antagonists. Acta Pharmacol Sin 2013; 34:1592-606. [PMID: 24304920 PMCID: PMC4002566 DOI: 10.1038/aps.2013.129] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/16/2013] [Indexed: 01/20/2023] Open
Abstract
AIM Both endothelin ETA receptor antagonists and angiotensin AT1 receptor antagonists lower blood pressure in hypertensive patients. A dual AT1 and ETA receptor antagonist may be more efficacious antihypertensive drug. In this study we identified the mode and mechanism of binding of imidazole series of compounds as dual AT1 and ETA receptor antagonists. METHODS Molecular modeling approach combining quantum-polarized ligand docking (QPLD), MM/GBSA free-energy calculation and 3D-QSAR analysis was used to evaluate 24 compounds as dual AT1 and ETA receptor antagonists and to reveal their binding modes and structural basis of the inhibitory activity. Pharmacophore-based virtual screening and docking studies were performed to identify more potent dual antagonists. RESULTS 3D-QSAR models of the imidazole compounds were developed from the conformer generated by QPLD, and the resulting models showed a good correlation between the predicted and experimental activity. The visualization of the 3D-QSAR model in the context of the compounds under study revealed the details of the structure-activity relationship: substitution of methoxymethyl and cyclooctanone might increase the activity against AT1 receptor, while substitution of cyclohexone and trimethylpyrrolidinone was important for the activity against ETA receptor; addition of a trimethylpyrrolidinone to compound 9 significantly reduced its activity against AT1 receptor but significantly increased its activity against ETA receptor, which was likely due to the larger size and higher intensities of the H-bond donor and acceptor regions in the active site of ETA receptor. Pharmacophore-based virtual screening followed by subsequent Glide SP, XP, QPLD and MM/GBSA calculation identified 5 potential lead compounds that might act as dual AT1 and ETA receptor antagonists. CONCLUSION This study may provide some insights into the development of novel potent dual ETA and AT1 receptor antagonists. As a result, five compounds are found to be the best dual antagonists against AT1R and ETA receptors.
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Affiliation(s)
| | - Karthikeyan Muthusamy
- Department of Bioinformatics, Alagappa University, Karaikudi – 630 004, Tamil Nadu, India
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Hamouda AK, Jayakar SS, Chiara DC, Cohen JB. Photoaffinity Labeling of Nicotinic Receptors: Diversity of Drug Binding Sites! J Mol Neurosci 2013; 53:480-6. [DOI: 10.1007/s12031-013-0150-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 10/10/2013] [Indexed: 12/11/2022]
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Fillion D, Cabana J, Guillemette G, Leduc R, Lavigne P, Escher E. Structure of the human angiotensin II type 1 (AT1) receptor bound to angiotensin II from multiple chemoselective photoprobe contacts reveals a unique peptide binding mode. J Biol Chem 2013; 288:8187-8197. [PMID: 23386604 DOI: 10.1074/jbc.m112.442053] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Breakthroughs in G protein-coupled receptor structure determination based on crystallography have been mainly obtained from receptors occupied in their transmembrane domain core by low molecular weight ligands, and we have only recently begun to elucidate how the extracellular surface of G protein-coupled receptors (GPCRs) allows for the binding of larger peptide molecules. In the present study, we used a unique chemoselective photoaffinity labeling strategy, the methionine proximity assay, to directly identify at physiological conditions a total of 38 discrete ligand/receptor contact residues that form the extracellular peptide-binding site of an activated GPCR, the angiotensin II type 1 receptor. This experimental data set was used in homology modeling to guide the positioning of the angiotensin II (AngII) peptide within several GPCR crystal structure templates. We found that the CXC chemokine receptor type 4 accommodated the results better than the other templates evaluated; ligand/receptor contact residues were spatially grouped into defined interaction clusters with AngII. In the resulting receptor structure, a β-hairpin fold in extracellular loop 2 in conjunction with two extracellular disulfide bridges appeared to open and shape the entrance of the ligand-binding site. The bound AngII adopted a somewhat vertical binding mode, allowing concomitant contacts across the extracellular surface and deep within the transmembrane domain core of the receptor. We propose that such a dualistic nature of GPCR interaction could be well suited for diffusible linear peptide ligands and a common feature of other peptidergic class A GPCRs.
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Affiliation(s)
- Dany Fillion
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Jérôme Cabana
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Gaétan Guillemette
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Richard Leduc
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Pierre Lavigne
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Emanuel Escher
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada.
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20
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Jurkowski W, Yazdi S, Elofsson A. Ligand binding properties of human galanin receptors. Mol Membr Biol 2012; 30:206-16. [DOI: 10.3109/09687688.2012.750384] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Cabana J, Holleran B, Beaulieu MÈ, Leduc R, Escher E, Guillemette G, Lavigne P. Critical hydrogen bond formation for activation of the angiotensin II type 1 receptor. J Biol Chem 2012; 288:2593-604. [PMID: 23223579 DOI: 10.1074/jbc.m112.395939] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors contain selectively important residues that play central roles in the conformational changes that occur during receptor activation. Asparagine 111 (N111(3.35)) is such a residue within the angiotensin II type 1 (AT(1)) receptor. Substitution of N111(3.35) for glycine leads to a constitutively active receptor, whereas substitution for tryptophan leads to an inactivable receptor. Here, we analyzed the AT(1) receptor and two mutants (N111G and N111W) by molecular dynamics simulations, which revealed a novel molecular switch involving the strictly conserved residue D74(2.50). Indeed, D74(2.50) forms a stable hydrogen bond (H-bond) with the residue in position 111(3.35) in the wild-type and the inactivable receptor. However, in the constitutively active mutant N111G-AT(1) receptor, residue D74 is reoriented to form a new H-bond with another strictly conserved residue, N46(1.50). When expressed in HEK293 cells, the mutant N46G-AT(1) receptor was poorly activable, although it retained a high binding affinity. Interestingly, the mutant N46G/N111G-AT(1) receptor was also inactivable. Molecular dynamics simulations also revealed the presence of a cluster of hydrophobic residues from transmembrane domains 2, 3, and 7 that appears to stabilize the inactive form of the receptor. Whereas this hydrophobic cluster and the H-bond between D74(2.50) and W111(3.35) are more stable in the inactivable N111W-AT(1) receptor, the mutant N111W/F77A-AT(1) receptor, designed to weaken the hydrophobic core, showed significant agonist-induced signaling. These results support the potential for the formation of an H-bond between residues D74(2.50) and N46(1.50) in the activation of the AT(1) receptor.
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Affiliation(s)
- Jérôme Cabana
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quecec J1H 5N4, Canada
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22
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Wangler NJ, Santos KL, Schadock I, Hagen FK, Escher E, Bader M, Speth RC, Karamyan VT. Identification of membrane-bound variant of metalloendopeptidase neurolysin (EC 3.4.24.16) as the non-angiotensin type 1 (non-AT1), non-AT2 angiotensin binding site. J Biol Chem 2011; 287:114-122. [PMID: 22039052 DOI: 10.1074/jbc.m111.273052] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, we discovered a novel non-angiotensin type 1 (non-AT1), non-AT2 angiotensin binding site in rodent and human brain membranes, which is distinctly different from angiotensin receptors and key proteases processing angiotensins. It is hypothesized to be a new member of the renin-angiotensin system. This study was designed to isolate and identify this novel angiotensin binding site. An angiotensin analog, photoaffinity probe 125I-SBpa-Ang II, was used to specifically label the non-AT1, non-AT2 angiotensin binding site in mouse forebrain membranes, followed by a two-step purification procedure based on the molecular size and isoelectric point of the photoradiolabeled binding protein. Purified samples were subjected to two-dimensional gel electrophoresis followed by mass spectrometry identification of proteins in the two-dimensional gel sections containing radioactivity. LC-MS/MS analysis revealed eight protein candidates, of which the four most abundant were immunoprecipitated after photoradiolabeling. Immunoprecipitation studies indicated that the angiotensin binding site might be the membrane-bound variant of metalloendopeptidase neurolysin (EC 3.4.24.16). To verify these observations, radioligand binding and photoradiolabeling experiments were conducted in membrane preparations of HEK293 cells overexpressing mouse neurolysin or thimet oligopeptidase (EC 3.4.24.15), a closely related metalloendopeptidase of the same family. These experiments also identified neurolysin as the non-AT1, non-AT2 angiotensin binding site. Finally, brain membranes of mice lacking neurolysin were nearly devoid of the non-AT1, non-AT2 angiotensin binding site, further establishing membrane-bound neurolysin as the binding site. Future studies will focus on the functional significance of this highly specific, high affinity interaction between neurolysin and angiotensins.
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Affiliation(s)
- Naomi J Wangler
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106
| | - Kira L Santos
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida 33328
| | - Ines Schadock
- Max-Delbrück-Center for Molecular Medicine, Berlin 13092, Germany
| | - Fred K Hagen
- Proteomics Center, Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642
| | - Emanuel Escher
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine, Berlin 13092, Germany
| | - Robert C Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida 33328; Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida 32611
| | - Vardan T Karamyan
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, Texas, 79106; Vascular Drug Research Center, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas 79106.
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Arsenault J, Cabana J, Fillion D, Leduc R, Guillemette G, Lavigne P, Escher E. Temperature dependent photolabeling of the human angiotensin II type 1 receptor reveals insights into its conformational landscape and its activation mechanism. Biochem Pharmacol 2010; 80:990-9. [DOI: 10.1016/j.bcp.2010.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 06/07/2010] [Accepted: 06/07/2010] [Indexed: 11/15/2022]
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Towards non-peptide ANG II AT1 receptor antagonists based on urocanic acid: rational design, synthesis and biological evaluation. Amino Acids 2010; 40:411-20. [PMID: 20607324 DOI: 10.1007/s00726-010-0651-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 06/02/2010] [Indexed: 10/19/2022]
Abstract
A series of o-, m- and p-benzyl tetrazole derivatives 11a-c has been designed, synthesized and evaluated as potential Angiotensin II AT1 receptor antagonists, based on urocanic acid. Compound 11b with tetrazole moiety at the m-position showed moderate, however, higher activity compared to the o- and p-counterpart analogues. Molecular modelling techniques were performed in order to extract their putative bioactive conformations and explore their binding modes.
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Karamyan VT, Arsenault J, Escher E, Speth RC. Preliminary biochemical characterization of the novel, non-AT1, non-AT2 angiotensin binding site from the rat brain. Endocrine 2010; 37:442-8. [PMID: 20960166 PMCID: PMC3176303 DOI: 10.1007/s12020-010-9328-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 03/25/2010] [Indexed: 12/26/2022]
Abstract
A novel binding site for angiotensins II and III was recently discovered in brain membranes in the presence of the sulfhydryl reactive angiotensinase inhibitor parachloromercuribenzoate. This binding site is distinctly different from the other known receptors for angiotensins: AT₁, AT₂, AT₄, and mas oncogene protein (Ang 1-7 receptor). Preliminary biochemical characterization studies have been done on this protein by crosslinking it with (125)I-labeled photoaffinity probes and solubilizing the radiolabeled binding site. Polyacrylamide gel electrophoresis studies and isoelectric focusing indicate that this membrane bound binding site is a protein with a molecular weight of 70-85 kDa and an isoelectric point of ~7. Cyanogen bromide hydrolysis of the protein yielded two radiolabeled fragments of 12.5 and 25 kDa. The protein does not appear to be N-glycosylated based upon the failure of PNGaseF to alter its migration rate on a 7.5% polyacrylamide gel. The binding of angiotensin II to this protein is not affected by GTPγS or Gpp(NH)p, suggesting that it is not a G protein-coupled receptor. Further characterization studies are directed to identify this protein either as a novel angiotensin receptor, an angiotensin scavenger (clearance receptor) or an angiotensinase.
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Affiliation(s)
- Vardan T. Karamyan
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University HSC, Amarillo, TX 79106, USA
| | - Jason Arsenault
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Emanuel Escher
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Robert C. Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, 3200 S. University Dr, Fort Lauderdale, FL 33328-2018, USA
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A single-nucleotide polymorphism of alanine to threonine at position 163 of the human angiotensin II type 1 receptor impairs Losartan affinity. Pharmacogenet Genomics 2010; 20:377-88. [DOI: 10.1097/fpc.0b013e32833a6d4a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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27
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Fillion D, Lemieux G, Basambombo LL, Lavigne P, Guillemette G, Leduc R, Escher E. The amino-terminus of angiotensin II contacts several ectodomains of the angiotensin II receptor AT1. J Med Chem 2010; 53:2063-75. [PMID: 20146480 DOI: 10.1021/jm9015747] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors and major targets for drug development. Herein, we sought to identify the regions of the human angiotensin II (AngII) type 1 (hAT(1)) receptor binding cleft that interact with all positions of the AngII using photoaffinity labeling. We conducted a complete iterative walk-through of the AngII sequence with either p-benzoyl-L-phenylalanine (Bpa) or p-[3-(trifluoromethyl)-3H-diazirin-3-yl]-L-phenylalanine (Tdf) to yield two series of eight photoreactive analogues. Pharmacological properties assessment of these sixteen analogues showed that the CAM receptor has a structure-activity relationship (SAR) more amenable to the amino acid substitutions at positions 1, 2, 3, and 5 of AngII than the WT receptor. Photoaffinity labeling of the CAM receptor with the selected analogues, which exhibit different but complementary photochemical properties, suggested that the AngII amino-terminus resides in a hydrophilic environment and interacts simultaneously with different regions of the hAT(1) receptor, including several ectodomains.
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Affiliation(s)
- Dany Fillion
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, QC, Canada
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Unal H, Jagannathan R, Bhat MB, Karnik SS. Ligand-specific conformation of extracellular loop-2 in the angiotensin II type 1 receptor. J Biol Chem 2010; 285:16341-50. [PMID: 20299456 DOI: 10.1074/jbc.m109.094870] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The orientation of the second extracellular loop (ECL2) is divergent in G-protein coupled receptor (GPCR) structures determined. This discovery provoked the question, is the ECL2 conformation differentially regulated in the GPCRs that respond to diffusible ligands? We have determined the conformation of the ECL2 of the angiotensin II type 1 receptor by reporter-cysteine accessibility mapping in different receptor states (i.e. empty, agonist-bound and antagonist-bound). We introduced cysteines at each position of ECL2 of an N-terminal epitope-tagged receptor surrogate lacking all non-essential cysteines and then measured reaction of these with a cysteine-reactive biotin probe. The ability of biotinylated mutant receptors to react with a steptavidin-HRP-conjugated antibody was used as the basis for examining differences in accessibility. Two segments of ECL2 were accessible in the empty receptor, indicating an open conformation of ECL2. These segments were inaccessible in the ligand-bound states of the receptor. Using the accessibility constraint, we performed molecular dynamics simulation to predict ECL2 conformation in different states of the receptor. Analysis suggested that a lid conformation similar to that of ECL2 in rhodopsin was induced upon binding both agonist and antagonist, but exposing different accessible segments delimited by the highly conserved disulfide bond. Our study reveals the ability of ECL2 to interact with diffusing ligands and to adopt a ligand-specific lid conformation, thus, slowing down dissociation of ligands when bound. Distinct conformations induced by the bound agonist and the antagonist around the conserved disulfide bond suggest an important role for this disulfide bond in producing different functional states of the receptor.
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Affiliation(s)
- Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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The KDEL receptor: new functions for an old protein. FEBS Lett 2009; 583:3863-71. [PMID: 19854180 DOI: 10.1016/j.febslet.2009.10.053] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 10/14/2009] [Accepted: 10/20/2009] [Indexed: 02/07/2023]
Abstract
The KDEL receptor is a seven-transmembrane-domain protein that was first described about 20 years ago. Its well-known function is to retrotransport chaperones from the Golgi complex to the endoplasmic reticulum. Recent studies, however, have suggested that the KDEL receptor has additional functions. Indeed, we have demonstrated that chaperone-bound KDEL receptor triggers the activation of Src family kinases on the Golgi complex. This activity is essential in the regulation of Golgi-to-plasma membrane transport. However, the identification of different KDEL receptor interactors that are inconsistent with these established functions opens the possibility of further receptor activities.
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Clément M, Cabana J, Holleran BJ, Leduc R, Guillemette G, Lavigne P, Escher E. Activation induces structural changes in the liganded angiotensin II type 1 receptor. J Biol Chem 2009; 284:26603-12. [PMID: 19635801 DOI: 10.1074/jbc.m109.012922] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The octapeptide hormone angiotensin II (AngII) binds to and activates the human angiotensin II type 1 receptor (hAT(1)) of the G protein-coupled receptor class A family. Several activation mechanisms have been proposed for this family, but they have not yet been experimentally validated. We previously used the methionine proximity assay to show that 11 residues in transmembrane domain (TMD) III, VI, and VII of the hAT(1) receptor reside in close proximity to the C-terminal residue of AngII. With the exception of a single change in TMD VI, the same contacts are present on N111G-hAT(1), a constitutively active mutant; this N111G-hAT(1) is a model for the active form of the receptor. In this study, two series of 53 individual methionine mutations were constructed in TMD I, II, IV, and V on both receptor forms. The mutants were photolabeled with a neutral antagonist, (125)I-[Sar(1),p-benzoyl-L-Phe(8)]AngII, and the resulting complexes were digested with cyanogen bromide. Although no new contacts were found for the hAT(1) mutants, two were found in the constitutively active mutants, Phe-77 in TMD II and Asn-200 in TMD V. To our knowledge, this is the first time that a direct ligand contact with TMD II and TMD V has been reported. These contact point differences were used to identify the structural changes between the WT-hAT(1) and N111G-hAT(1) complexes through homology-based modeling and restrained molecular dynamics. The model generated revealed an important structural rearrangement of several TMDs from the basal to the activated form in the WT-hAT(1) receptor.
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Affiliation(s)
- Martin Clément
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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Holleran BJ, Domazet I, Beaulieu ME, Yan LP, Guillemette G, Lavigne P, Escher E, Leduc R. Identification of transmembrane domain 6 & 7 residues that contribute to the binding pocket of the urotensin II receptor. Biochem Pharmacol 2009; 77:1374-82. [DOI: 10.1016/j.bcp.2009.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 01/20/2009] [Accepted: 01/21/2009] [Indexed: 11/16/2022]
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Clérico EM, Szymańska A, Gierasch LM. Exploring the interactions between signal sequences and E. coli SRP by two distinct and complementary crosslinking methods. Biopolymers 2009; 92:201-11. [PMID: 19280642 PMCID: PMC2896254 DOI: 10.1002/bip.21181] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Photoaffinity crosslinking comprises a group of invaluable techniques used to investigate in detail a binding interaction between two polypeptides. As the diverse photo crosslinking techniques available display inherent differences, the method of choice will provide specific information about a particular system under study. We used two complementary crosslinking approaches: photo-induced crosslinking of unmodified proteins (PICUP) and benzophenone-mediated (BPM) crosslinking to extensively examine the interaction between the signal recognition particle (SRP) and signal sequences. Signal peptide binding by SRP presents a central puzzle in the protein targeting process because signal sequences must be recognized with fidelity but lack strict primary structural homology. The concurrent use of PICUP and BPM crosslinking to link signal peptides to E. coli SRP allowed us to explore the crosslinking pattern resulting from using different crosslinking chemistries, varying the position of the photoprobe in the hydrophobic core of the signal sequence, and shifting the crosslinking reactive group away from the signal peptide backbone. By PICUP, signal peptides crosslinked exclusively to the NG domain of the SRP protein Ffh, regardless of the position of the reactive residue. Benzophenone-modified amino acids preferentially crosslinked the signal peptide to the C-terminal (M) domain of Ffh. We conclude that signal peptide binding is largely mediated by the M domain. Importantly, our data also indicate intimate, at least transient, contacts between the hydrophobic core of the signal peptide and the NG domain. These results reopen the possibility of a direct involvement of the NG domain in signal sequence recognition.
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Affiliation(s)
- Eugenia M. Clérico
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst MA 01003, U.S.A
- Department of Chemistry, University of Massachusetts, Amherst MA 01003, U.S.A
| | - Aneta Szymańska
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst MA 01003, U.S.A
- Department of Chemistry, University of Massachusetts, Amherst MA 01003, U.S.A
- Department of Chemistry, University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland
| | - Lila M. Gierasch
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst MA 01003, U.S.A
- Department of Chemistry, University of Massachusetts, Amherst MA 01003, U.S.A
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33
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Moretto A, Crisma M, Formaggio F, Huck L, Mangion D, Leigh W, Toniolo C. Photoinduced Intramolecular Macrocyclization Reaction between a Bpa and a Met Residue in a Helical Peptide: 3D Structures of the Diastereomeric Products. Chemistry 2009; 15:67-70. [DOI: 10.1002/chem.200802066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Temperature-induced Ligand Contact Point Variations of the hAT1 Receptor and of the Constitutively Active Mutant N111G-hAT1. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009. [DOI: 10.1007/978-0-387-73657-0_151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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35
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Aplin M, Bonde MM, Hansen JL. Molecular determinants of angiotensin II type 1 receptor functional selectivity. J Mol Cell Cardiol 2009; 46:15-24. [DOI: 10.1016/j.yjmcc.2008.09.123] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/09/2008] [Accepted: 09/18/2008] [Indexed: 01/14/2023]
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36
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Clément M, Chamberland C, Pérodin J, Leduc R, Guillemette G, Escher E. The Active and the Inactive Form of the hAT1Receptor Have an Identical Ligand-Binding Environment: An MPA Study on a Constitutively Active Angiotensin II Receptor Mutant. J Recept Signal Transduct Res 2008; 26:417-33. [PMID: 17118790 DOI: 10.1080/10799890600923195] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Several models of activation mechanisms were proposed for G protein-coupled receptors (GPCRs), yet no direct methods exist for their elucidation. The availability of constitutively active mutants has given an opportunity to study active receptor conformations within acceptable limits using models such as the angiotensin II type 1 (AT1)1 receptor mutant N111G-hAT1 which displays an important constitutive activity. Recently, by using methionine proximity assay, we showed for the hAT1 receptor that TMD III, VI, and VII form the ligand-binding pocket of the C-terminal amino acid of an antagonistic AngII analogue. In the present contribution, we investigated whether the same residues would also constitute the ligand-binding contacts in constitutively activated mutant (CAM) receptors. For this purpose, the same Met mutagenesis strategy was carried out on the N111G double mutants. Analysis of 43 receptors mutants in the N111G-hAT1 series, photolabeled and CNBr digested, showed that there were only subtle structural changes between the wt-receptor and its constitutively active form.
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Affiliation(s)
- Martin Clément
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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37
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Gagnon T, Fillion D, Lefebvre MR, Escher E. Synthesis of an Agonistic, Difluoro-Azido Photolabel of Angiotensin II and Labeling of the AT1Receptor: Transmembrane Domains 3, 6, and 7 Form the Ligand-Binding Pocket. J Recept Signal Transduct Res 2008; 26:435-51. [PMID: 17118791 DOI: 10.1080/10799890600923161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
p-Azido-phenylalanine has been frequently used for photoaffinity labeling of target proteins such as the angiotensin receptors. However, chemical studies showed that simple aryl nitrenes first react intramolecularly, forming a semistable cyclic keteneimine and then reacting with nucleophile residues in the target structure like those of lysine and arginine. We synthesized 3,5-difluoro-4-azidophenylalanine where the formation of the keteneimine is prevented and where photoincorporation should be due to nonselective nitrene insertion only. This new amino acid was introduced in position 8 of angiotensin II and compared with the corresponding azidophenylalanine peptide using human AT1 receptor as target. The new photolabel maintained full agonist activity and a similar yield of photolabeling but without the previously observed gradual hydrolysis. Several selective proteolyses of the labeled receptor indicate that the new photolabel forms three simultaneous contact regions on the hAT1 receptor, suggestive of a nonselective behavior of the photolabel. A major contact was established in the sixth transmembrane domain but also in the third and seventh domain. Our results are in excellent agreement with those recently obtained from methionine proximity assay studies.
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Affiliation(s)
- Tommy Gagnon
- Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada
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38
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Aubin J, Létourneau M, Francoeur E, Burgeon E, Fournier A. Identification of ETA and ETB binding domains using ET-derived photoprobes. Biochimie 2008; 90:918-29. [DOI: 10.1016/j.biochi.2008.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2007] [Accepted: 02/14/2008] [Indexed: 01/29/2023]
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39
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Monaghan P, Thomas BE, Woznica I, Wittelsberger A, Mierke DF, Rosenblatt M. Mapping peptide hormone-receptor interactions using a disulfide-trapping approach. Biochemistry 2008; 47:5889-95. [PMID: 18459800 DOI: 10.1021/bi800122f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Efforts to elucidate the nature of the bimolecular interaction of parathyroid hormone (PTH) with its cognate receptor, the PTH receptor type 1 (PTHR1), have relied heavily on benzoylphenylalanine- (Bpa-) based photoaffinity cross-linking. However, given the flexibility, size, and shape of Bpa, the resolution at the PTH-PTHR1 interface appears to be reaching the limit of this technique. Here we employ a disulfide-trapping approach developed by others primarily for use in screening compound libraries to identify novel ligands. In this method, cysteine substitutions are introduced into a specific site within the ligand and a region in the receptor predicted to interact with each other. Upon ligand binding, if these cysteines are in close proximity, they form a disulfide bond. Since the geometry governing disulfide bond formation is more constrained than Bpa cross-linking, this novel approach can be employed to generate a more refined molecular model of the PTH-PTHR1 complex. Using a PTH analogue containing a cysteine at position 1, we probed 24 sites and identified 4 in PTHR1 to which cross-linking occurred. Importantly, previous photoaffinity cross-linking studies using a PTH analogue with Bpa at position 1 only identified a single interaction site. The new sites identified by the disulfide-trapping procedure were used as constraints in molecular dynamics simulations to generate an updated model of the PTH-PTHR1 complex. Mapping by disulfide trapping extends and complements photoaffinity cross-linking. It is applicable to other peptide-receptor interfaces and should yield insights about yet unknown sites of ligand-receptor interactions, allowing for generation of more refined models.
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Affiliation(s)
- Paul Monaghan
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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40
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Wittelsberger A, Mierke DF, Rosenblatt M. Mapping ligand-receptor interfaces: approaching the resolution limit of benzophenone-based photoaffinity scanning. Chem Biol Drug Des 2008; 71:380-3. [PMID: 18312550 DOI: 10.1111/j.1747-0285.2008.00646.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photoaffinity crosslinking has yielded important insights in the study of G protein-coupled receptors and the mode of ligand binding. The most widely used photolabile moiety is p-benzoylphenylalanine largely because of its reportedly high site specificity, reduced reactivity to water and light, photokinetics, and ease of incorporation into peptide ligands during synthesis. However, in the course of our studies directed at characterizing the binding of parathyroid hormone to its cognate G protein-coupled receptor, we find that inherent properties of p-benzoylphenylalanine, such as its size and conformational flexibility, limit the resulting resolution of the ligand-receptor structure. Here, we examine and define these limits.
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41
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Nikiforovich GV, Marshall GR, Baranski TJ. Modeling molecular mechanisms of binding of the anaphylatoxin C5a to the C5a receptor. Biochemistry 2008; 47:3117-30. [PMID: 18275159 DOI: 10.1021/bi702321a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study presents the 3D model of the complex between the anaphylatoxin C5a and its specific receptor, C5aR. This is the first 3D model of a G-protein-coupled receptor (GPCR) complex with a peptide ligand deduced by a molecular modeling procedure analyzing various conformational possibilities of the extracellular loops and the N-terminal segment of the GPCR. The modeling results indicated two very different ways of interacting between C5a and C5aR at the two interaction sites suggested earlier based on the data of site-directed mutagenesis. Specifically, C5a and C5aR can be involved in "mutual-induced fit", where the interface between the molecules is determined by both the receptor and the ligand. The rigid core of the C5a ligand selects the proper conformations of the highly flexible N-terminal segment of C5aR (the first interaction site). At the same time, the binding conformation of the flexible C-terminal fragment of C5a is selected by well-defined interactions with the TM region of the C5aR receptor (the second interaction site). The proposed 3D model of C5a/C5aR complex was built without direct use of structural constraints derived from site-directed mutagenesis reserving those data for validation of the model. The available data of site-directed mutagenesis of C5a and C5aR were successfully rationalized with the help of the model. Also, the modeling results predicted that the full-length C5a and C5a-des74 metabolite would have different binding modes with C5aR. Modeling approaches employed in this study are readily applicable for studies of molecular mechanisms of binding of other polypeptide ligands to their specific GPCRs.
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Affiliation(s)
- Gregory V Nikiforovich
- Center for Computational Biology, Department of Biochemistry and Molecular Biophysics, Washington University Medical School, St. Louis, Missouri 63110, USA.
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42
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Modeling binding modes of angiotensin II and pseudopeptide analogues to the AT2 receptor. J Mol Graph Model 2008; 26:991-1003. [DOI: 10.1016/j.jmgm.2007.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 08/16/2007] [Accepted: 08/21/2007] [Indexed: 11/17/2022]
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43
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Vodovozova EL. Photoaffinity labeling and its application in structural biology. BIOCHEMISTRY (MOSCOW) 2007; 72:1-20. [PMID: 17309432 DOI: 10.1134/s0006297907010014] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This review contains a brief consideration of some theoretical aspects of photoaffinity (photoreactive) labeling (PAL), and the most widely used photoreactive groups, such as arylazide, benzophenone, and 3-(trifluoromethyl)-3-phenyldiazirine, are characterized in comparison. Experimental methodology is described, including modern approaches of mass spectrometry for analysis of cross-linking products between the photoreactive probes and biomolecules. Examples of PAL application in diverse fields of structural biology during the last five-ten years are presented. Potential drug targets, transport processes, stereochemistry of interaction of G-protein-coupled receptors with ligands, as well as structural changes in nicotinic acetylcholine receptor are considered. Applications of photoaffinity ganglioside and phospholipid probes for studying biological membranes and of nucleotide probes in investigations of replicative and transcriptional complexes, as well as photoaffinity glycoconjugates for detecting carbohydrate-binding proteins are covered. In combination with modern techniques of instrumental analysis and computer-aided modeling, PAL remains the most important approach in studies on the organization of biological systems.
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Affiliation(s)
- E L Vodovozova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
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44
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Martin SS, Holleran BJ, Escher E, Guillemette G, Leduc R. Activation of the Angiotensin II Type 1 Receptor Leads to Movement of the Sixth Transmembrane Domain: Analysis by the Substituted Cysteine Accessibility Method. Mol Pharmacol 2007; 72:182-90. [PMID: 17446269 DOI: 10.1124/mol.106.033670] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of transmembrane domain six (TMD6) of the angiotensin II type 1 receptor, which is predicted to undergo conformational changes after agonist binding, was investigated using the substituted-cysteine accessibility method. Each residue in the Lys240-Leu265 fragment was mutated, one at a time, to a cysteine. The resulting mutants were expressed in COS-7 cells, which were subsequently treated with the charged sulfhydryl-specific alkylating agent methanethiosulfonate-ethylammonium (MTSEA). This treatment led to a significant reduction in binding of (125)I-[Sar(1),Ile(8)]AngII to the F249C, H256C, T260C, and V264C mutant receptors, suggesting that these residues orient themselves within the water-accessible binding pocket of the AT(1) receptor. It is noteworthy that this pattern of acquired MTSEA sensitivity was altered for TMD6 cysteines engineered in a constitutively active AT(1) receptor. Indeed, mutant F249C was insensitive to MTSEA treatment, whereas the sensitivity of mutant V264C decreased. Under these conditions, one other mutant, F261C, was found to be sensitive to MTSEA treatment. Our results suggest that constitutive activation of the AT(1) receptor causes TMD6 to pivot. This movement moves the top (extracellular side) of TMD6 toward the binding pocket and simultaneously distances the bottom (intracellular side) away from the binding pocket. Using this approach, we identified key elements within TMD6 that contribute to the activation of class A GPCRs through structural rearrangements.
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Affiliation(s)
- Stéphane S Martin
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, Quebec, Canada, J1H 5N4
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45
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Oliveira L, Costa-Neto CM, Nakaie CR, Schreier S, Shimuta SI, Paiva ACM. The Angiotensin II AT1 Receptor Structure-Activity Correlations in the Light of Rhodopsin Structure. Physiol Rev 2007; 87:565-92. [PMID: 17429042 DOI: 10.1152/physrev.00040.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The most prevalent physiological effects of ANG II, the main product of the renin-angiotensin system, are mediated by the AT1 receptor, a rhodopsin-like AGPCR. Numerous studies of the cardiovascular effects of synthetic peptide analogs allowed a detailed mapping of ANG II's structural requirements for receptor binding and activation, which were complemented by site-directed mutagenesis studies on the AT1 receptor to investigate the role of its structure in ligand binding, signal transduction, phosphorylation, binding to arrestins, internalization, desensitization, tachyphylaxis, and other properties. The knowledge of the high-resolution structure of rhodopsin allowed homology modeling of the AT1 receptor. The models thus built and mutagenesis data indicate that physiological (agonist binding) or constitutive (mutated receptor) activation may involve different degrees of expansion of the receptor's central cavity. Residues in ANG II structure seem to control these conformational changes and to dictate the type of cytosolic event elicited during the activation. 1) Agonist aromatic residues (Phe8 and Tyr4) favor the coupling to G protein, and 2) absence of these residues can favor a mechanism leading directly to receptor internalization via phosphorylation by specific kinases of the receptor's COOH-terminal Ser and Thr residues, arrestin binding, and clathrin-dependent coated-pit vesicles. On the other hand, the NH2-terminal residues of the agonists ANG II and [Sar1]-ANG II were found to bind by two distinct modes to the AT1 receptor extracellular site flanked by the COOH-terminal segments of the EC-3 loop and the NH2-terminal domain. Since the [Sar1]-ligand is the most potent molecule to trigger tachyphylaxis in AT1 receptors, it was suggested that its corresponding binding mode might be associated with this special condition of receptors.
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Affiliation(s)
- Laerte Oliveira
- Department of Biophysics, Escola Paulista de Medicina, Federal University of São Paulo, Brazil.
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46
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Holleran B, Beaulieu ME, Proulx C, Lavigne P, Escher E, Leduc R. Photolabelling the urotensin II receptor reveals distinct agonist- and partial-agonist-binding sites. Biochem J 2007; 402:51-61. [PMID: 17064254 PMCID: PMC1783990 DOI: 10.1042/bj20060943] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mechanism by which GPCRs (G-protein-coupled receptors) undergo activation is believed to involve conformational changes following agonist binding. We have used photoaffinity labelling to identify domains within GPCRs that make contact with various photoreactive ligands in order to better understand the activation mechanism. Here, a series of four agonist {[Bpa1]U-II (Bpa is p-benzoyl-L-phenylalanine), [Bpa2]U-II, [Bpa3]U-II and [Bpa4]U-II} and three partial agonist {[Bpa1Pen5D-Trp7Orn8]U-II (Pen is penicillamine), [Bpa2Pen5D-Trp7Orn8]U-II and [Pen5Bpa6D-Trp7Orn8]U-II} photoreactive urotensin II (U-II) analogues were used to identify ligand-binding sites on the UT receptor (U-II receptor). All peptides bound the UT receptor expressed in COS-7 cells with high affinity (Kd of 0.3-17.7 nM). Proteolytic mapping and mutational analysis led to the identification of Met288 of the third extracellular loop of the UT receptor as a binding site for all four agonist peptides. Both partial agonists containing the photoreactive group in positions 1 and 2 also cross-linked to Met288. We found that photolabelling with the partial agonist containing the photoreactive group in position 6 led to the detection of transmembrane domain 5 as a binding site for that ligand. Interestingly, this differs from Met184/Met185 of the fourth transmembrane domain that had been identified previously as a contact site for the full agonist [Bpa6]U-II. These results enable us to better map the binding pocket of the UT receptor. Moreover, the data also suggest that, although structurally related agonists or partial agonists may dock in the same general binding pocket, conformational changes induced by various states of activation may result in slight differences in spatial proximity within the cyclic portion of U-II analogues.
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Affiliation(s)
- Brian J. Holleran
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Ave. N., Sherbrooke, Québec, Canada J1H 5N4
| | - Marie-Eve Beaulieu
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Ave. N., Sherbrooke, Québec, Canada J1H 5N4
| | - Christophe D. Proulx
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Ave. N., Sherbrooke, Québec, Canada J1H 5N4
| | - Pierre Lavigne
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Ave. N., Sherbrooke, Québec, Canada J1H 5N4
| | - Emanuel Escher
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Ave. N., Sherbrooke, Québec, Canada J1H 5N4
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47
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Arsenault J, Renaud MPLH, Clément M, Fillion D, Guillemette G, Leduc R, Lavigne P, Escher E. Temperature-dependent variations of ligand-receptor contact points in hAT1. J Pept Sci 2007; 13:575-80. [PMID: 17600857 DOI: 10.1002/psc.875] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Photoaffinity labelling is regularly used to investigate proteins, including peptidergic G protein-coupled receptors (GPCR). To this purpose benzophenone photolabels have been widely used to identify many contact residues in ligand-binding pockets. The three-dimensional binding environment of the human angiotensin II type 1 receptor hAT(1) has been determined using an iterative methionine mutagenesis strategy based on the photochemical properties and preferential incorporation of benzophenone onto methionine. This has led to the construction of a ligand-bound receptor structure. The present study investigated the effect of temperature on the accessibility of some of these contact points. The hAT(1) receptor and two representative Met mutants (H256M-hAT(1) and F293M-hAT(1)) from the iterative mutagenesis study were photolabelled with the benzophenone-ligand (125)I-[Sar(1), Bpa(8)]AngII at temperatures ranging from - 15 degrees C to 37 degrees C. Labelled receptors were partially purified and digested with cyanogen bromide to identify the contact points or segments. There were no changes in receptor contacts or labelling in the 7th transmembrane domains (TMD) of hAT(1) and F293M-hAT(1) across the temperature range. However, a temperature-dependent change in the ligand-receptor contact of H256M-hAT(1) was observed. At - 15 degrees C, H256M labelling was identical to that of hAT(1), indicating that the interaction was specific to the 7th TMD. Significant labelling changes were observed at higher temperatures and at 37 degrees C labelling occurred almost exclusively at mutated residue H256M-hAT(1) in the 6th TMD. Simultaneous competitive labelling of different areas of this target protein indicated that the ligand-receptor structure became increasingly fluctual at physiological temperatures, while a more compact, low mobility, and low energy conformation prevailed at low temperatures.
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Affiliation(s)
- J Arsenault
- Département de pharmacologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ième Avenue Nord, Sherbrooke, Quebec, J1H 5N4, Canada
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Clément M, Escher E. [The methionine proximity assay: an approach to glean receptor structures]. Med Sci (Paris) 2006; 22:1017-8. [PMID: 17156715 DOI: 10.1051/medsci/200622121017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nikiforovich GV, Zhang M, Yang Q, Jagadeesh G, Chen HC, Hunyady L, Marshall GR, Catt KJ. Interactions between Conserved Residues in Transmembrane Helices 2 and 7 during Angiotensin AT1Receptor Activation. Chem Biol Drug Des 2006; 68:239-49. [PMID: 17177883 DOI: 10.1111/j.1747-0285.2006.00444.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Site-directed mutagenesis studies and independent molecular modeling studies were combined to investigate the network of inter-residue interactions within the transmembrane region of the angiotensin AT(1a) receptor. Site-directed mutagenesis was focused on residues Tyr292, Asn294, Asn295, and Asn298 in transmembrane helix 7, and the conserved Asp74 in helix 2 and other polar residues. Functional interactions between pairs of residues were evaluated by determining the effects of single and double-reciprocal mutations on agonist-induced AT(1a) receptor activation. Replacement of Tyr292 by aspartate in helix 7 abolished radioligand binding to both Y292D and D74Y/Y292D mutant receptors. Reciprocal mutations of Asp74/Asn294, Ser115/Asn294, Ser252/Asn294, and Asn298/Sen115 caused additive impairment of function, suggesting that these pairs of residues make independent contributions to AT(1a) receptor activation. In contrast, mutations of the Asp74/Tyr298 pair revealed that the D74N/N298D reciprocal mutation substantially increased the impaired inositol phosphate responses of the D74N and N298D receptors. Extensive molecular modeling yielded 3D models of the TM region of the AT(1) receptor and the mutants as well as of their complexes with angiotensin II, which were used to rationalize the possible reasons of impairing of function of some mutants. These data indicate that Asp74 and Asn298 are not optimally positioned for direct strong interaction in the resting conformation of the AT(1a) receptor. Balance of interactions between residues in helix 2 (as D74) and helix 7 (as N294, N295 and N298) in the AT(1) receptors, however, has a crucial role both in determining their functional activity and levels of their expression.
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Affiliation(s)
- Gregory V Nikiforovich
- Department of Biochemistry and Molecular Biophysics, Washington University Medical School, St Louis, MO 63110, USA.
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Martinelli A, Tuccinardi T. An overview of recent developments in GPCR modelling: methods and validation. Expert Opin Drug Discov 2006; 1:459-76. [DOI: 10.1517/17460441.1.5.459] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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