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Eastman KS, Mifflin MC, Oblad PF, Roberts AG, Bandarian V. A Promiscuous rSAM Enzyme Enables Diverse Peptide Cross-linking. ACS BIO & MED CHEM AU 2023; 3:480-493. [PMID: 38144258 PMCID: PMC10739248 DOI: 10.1021/acsbiomedchemau.3c00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 12/26/2023]
Abstract
Ribosomally produced and post-translationally modified polypeptides (RiPPs) are a diverse group of natural products that are processed by a variety of enzymes to their biologically relevant forms. PapB is a member of the radical S-adenosyl-l-methionine (rSAM) superfamily that introduces thioether cross-links between Cys and Asp residues in the PapA RiPP. We report that PapB has high tolerance for variations in the peptide substrate. Our results demonstrate that branched side chains in the thiol- and carboxylate-containing residues are processed and that lengthening of these groups to homocysteine and homoglutamate does not impair the ability of PapB to form thioether cross-links. Remarkably, the enzyme can even cross-link a peptide substrate where the native Asp carboxylate moiety is replaced with a tetrazole. We show that variations to residues embedded between the thiol- and carboxylate-containing residues are tolerated by PapB, as peptides containing both bulky (e.g., Phe) and charged (e.g., Lys) side chains in both natural L- and unnatural D-forms are efficiently cross-linked. Diastereomeric peptides bearing (2S,3R)- and (2S,3S)-methylaspartate are processed by PapB to form cyclic thioethers with markedly different rates, suggesting the enzymatic hydrogen atom abstraction event for the native Asp-containing substrate is diastereospecific. Finally, we synthesized two diastereomeric peptide substrates bearing E- and Z-configured γ,δ-dehydrohomoglutamate and show that PapB promotes addition of the deoxyadenosyl radical (dAdo•) instead of hydrogen atom abstraction. In the Z-configured γ,δ-dehydrohomoglutamate substrate, a fraction of the dAdo-adduct peptide is thioether cross-linked. In both cases, there is evidence for product inhibition of PapB, as the dAdo-adducts likely mimic the native transition state where dAdo• is poised to abstract a substrate hydrogen atom. Collectively, these findings provide critical insights into the arrangement of reacting species in the active site of the PapB, reveal unusual promiscuity, and highlight the potential of PapB as a tool in the development peptide therapeutics.
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Affiliation(s)
- Karsten
A. S. Eastman
- Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake
City, Utah 84112, United States
| | - Marcus C. Mifflin
- Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake
City, Utah 84112, United States
| | - Paul F. Oblad
- Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake
City, Utah 84112, United States
| | - Andrew G. Roberts
- Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake
City, Utah 84112, United States
| | - Vahe Bandarian
- Department of Chemistry, University of Utah, 315 S. 1400 E, Salt Lake
City, Utah 84112, United States
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2
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Gandham SK, Kudale AA, Allaka TR, Chepuri K, Jha A. New tetrazolopyrrolidine-1,2,3-triazole analogues as potent anticancer agents: design, synthesis and molecular docking studies. Mol Divers 2023:10.1007/s11030-023-10762-z. [PMID: 37938509 DOI: 10.1007/s11030-023-10762-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 10/31/2023] [Indexed: 11/09/2023]
Abstract
1,2,3-Triazole and tetrazole derivatives bearing pyrrolidines are found to exhibit notable biological activity and have become useful scaffolds in medicinal chemistry for application in lead discovery and optimization. We report design, synthesis and molecular docking studies of tetrazolyl-1,2,3-triazole derivatives (7a-i) bearing pyrrolidine moiety and evaluating their anticancer activity against four cancer cell lines viz. Hela, MCF-7, HCT-116 and HepG2. The structures of the new compounds were ascertained by spectral means IR, NMR: 1H &13C and Mass spectrum. From the studies compounds7a and 7i exhibited significant anticancer activity against the Hela cell line with IC50 = 0.32 ± 1.00, 1.80 ± 0.22 μM when compared to reference drug Doxorubicin (IC50 = 2.34 ± 0.11 μM), whereas 7h, 7i, and 7b were found to be active against MCF-7, HCT-116 and HepG2 cell lines with IC50 = 3.20 ± 1.40, 1.38 ± 0.06 and 0.97 ± 0.12 μM respectively. Notably 7a exhibited highest conventional hydrogen bondings TyrA:40, SerA:17, LysA:117, AlaA:146, Tyr218 with 3HB4and SerA:17, LysA:117, AlaA:146, TyrA:40 with 6IBZ and docking energy - 10.85, - 8.21 kcal/mol respectively. These compounds were further evaluated for their ADMET and physicochemical properties by using SwissADME. The results of the in vitro and in silico studies suggest that the tetrazole incorporated pyrrolidine-triazoles may possess the ideal structural requirements for further developing new anticancer agents.
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Affiliation(s)
- Siva Kumar Gandham
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh, 530045, India
| | - Amit A Kudale
- Research and Development, ASolution Pharmaceuticals Pvt Ltd, Dist. Thane, Ambernath, Maharashtra, 421506, India
| | - Tejeswara Rao Allaka
- Department of Chemistry, Centre for Chemical Sciences and Technology, Institute of Science & Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, Telangana, 500085, India
| | - Kalyani Chepuri
- Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, Telangana, 500085, India
| | - Anjali Jha
- Department of Chemistry, GITAM School of Science, GITAM (Deemed to be University), Gandhi Nagar, Rushikonda, Visakhapatnam, Andhra Pradesh, 530045, India.
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3
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Yang Y, Liang J, Li W, Yang W, Wang C, Zhang X, Fang WH, Guo Z, Chen X. Mechanistic Understanding and Reactivity Analyses for the Photochemistry of Disubstituted Tetrazoles. J Phys Chem A 2023; 127:4115-4124. [PMID: 37133205 DOI: 10.1021/acs.jpca.3c01594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The photolysis of tetrazoles has undergone extensive research. However, there are still some problems to be solved in terms of mechanistic understanding and reactivity analyses, which leaves room for theoretical calculations. Herein, multiconfiguration perturbation theory at the CASPT2//CASSCF level was employed to account for electron correction effects involved in the photolysis of four disubstituted tetrazoles. Based on calculations of vertical excitation properties and evaluations of intersystem crossing (ISC) efficiencies in the Frank-Condon region, the combination of space and electronic effects is found in maximum-absorption excitation. Two types of ISC (1ππ* → 3nπ*, 1ππ* → 3ππ*) are determined in disubstituted tetrazoles, and the obtained rates follow the El-Sayed rule. Through mapping three representative types of minimum energy profiles for the photolysis of 1,5-, and 2,5-disubstituted tetrazoles, a conclusion can be drawn that the photolysis of tetrazoles exhibits reactivity characteristic of bond-breaking selectivity. Kinetic evaluations show that the photogeneration of singlet imidoylnitrene operates predominately over that in the triplet state, which can be confirmed by a double-well model in the triplet potential energy surface of 1,5-disubstituted tetrazole. Similar mechanistic explorations and reactivity analyses were also applied to the photolysis of 2,5-disubstituted tetrazole to unveil fragmentation patterns of nitrile imine generation. All computational efforts allow us to better understand the photoreactions of disubstituted tetrazoles and to provide useful strategies for regulating their unique reactivity.
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Affiliation(s)
- Yanting Yang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jing Liang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Weijia Li
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wenjing Yang
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Chu Wang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xiaorui Zhang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zhen Guo
- College of Materials Science & Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, People's Republic of China
| | - Xuebo Chen
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
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4
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Singh KD, Karnik SS. Structural perspectives on the mechanism of signal activation, ligand selectivity and allosteric modulation in angiotensin receptors: IUPHAR Review 34. Br J Pharmacol 2022; 179:4461-4472. [PMID: 35318654 PMCID: PMC9398925 DOI: 10.1111/bph.15840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/14/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022] Open
Abstract
Functional advances have guided our knowledge of physiological and fatal pathological mechanisms of the hormone angiotensin II (AngII) and its antagonists. Such studies revealed that tissue response to a given dose of the hormone or its antagonist depends on receptors that engage the ligand. Thus, we need to know much more about the structures of receptor-ligand complexes at high resolution. Recently, X-ray structures of both AngII receptors (AT1 and AT2 receptors) bound to peptide and non-peptide ligands have been elucidated, providing new opportunities to examine the dynamic fluxes in the 3D architecture of the receptors, as the basis of ligand selectivity, efficacy, and regulation of the molecular functions of the receptors. Constituent structural motifs cooperatively transform ligand selectivity into specific functions, thus conceptualizing the primacy of the 3D structure over individual motifs of receptors. This review covers the new data elucidating the structural dynamics of AngII receptors and how structural knowledge can be transformative in understanding the mechanisms underlying the physiology of AngII.
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Affiliation(s)
- Khuraijam Dhanachandra Singh
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Sadashiva S. Karnik
- Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Verma A, Kaur B, Venugopal S, Wadhwa P, Sahu S, Kaur P, Kumar D, Sharma A. Tetrazole: A privileged scaffold for the discovery of anti-cancer agents. Chem Biol Drug Des 2022; 100:419-442. [PMID: 35713482 DOI: 10.1111/cbdd.14103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/02/2022] [Accepted: 06/12/2022] [Indexed: 11/28/2022]
Abstract
Carcinoma, characterized by abnormal growth of cells and tissue, is a ubiquitously leading cause of mortality across the globe due to some carcinogenic factors. Currently, several anticancer agents are commercially available in the global market. However, due to their resistance and cost, researchers are gaining more interest in developing newer novel potential anticancer agents. In the search for new drugs for clinical use, the tetrazole ring system has emerged as an exciting prospect in the optimization studies of promising lead molecules. Among the various heterocyclic agents, tetrazole-containing compounds have shown significant promise in the treatment of a wide range of diseases, particularly cancer. Here, in this review, we focused on several synthetic approaches for the synthesis of tetrazole analogues, their targets for treating cancer along with the biological activity of some of the recently reported tetrazole-containing anticancer agents.
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Affiliation(s)
- Anil Verma
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Balwinder Kaur
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Sneha Venugopal
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Pankaj Wadhwa
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Sanjeev Sahu
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Paranjeet Kaur
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Punjab, India
| | - Deepak Kumar
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, India
| | - Ajit Sharma
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, India
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6
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Farrokhzadeh A, Modarresi-Alam AR, Akher FB, Kleinpeter E, Kelling A, Schilde U. Investigation of the unusually high rotational energy barrier about the C-N bond in 5-(2-x-phenyl)-N,N-dimethyl-2H-tetrazole-2-carboxamides: Insights from dynamic 1H-NMR and DFT calculations. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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7
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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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Dhiman N, Kaur K, Jaitak V. Tetrazoles as anticancer agents: A review on synthetic strategies, mechanism of action and SAR studies. Bioorg Med Chem 2020; 28:115599. [PMID: 32631569 DOI: 10.1016/j.bmc.2020.115599] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 12/22/2022]
Abstract
Cancer is a leading cause of death worldwide. Even after the availability of numerous drugs and treatments in the market, scientists and researchers are focusing on new therapies because of their resistance and toxicity issues. The newly synthesized drug candidates are able to demonstrate in vitro activity but are unable to reach clinical trials due to their rapid metabolism and low bioavailability. Therefore there is an imperative requisite to expand novel anticancer negotiators with tremendous activity as well as in vivo efficacy. Tetrazole is a promising pharmacophore which is metabolically more stable and acts as a bioisosteric analogue for many functional groups. Tetrazole fragment is often castoff with other pharmacophores in the expansion of novel anticancer drugs. This is the first systematic review that emphasizes on contemporary strategies used for the inclusion of tetrazole moiety, mechanistic targets along with comprehensive structural activity relationship studies to provide perspective into the rational design of high-efficiency tetrazole-based anticancer drug candidates.
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Affiliation(s)
- Neha Dhiman
- Department of Pharmaceutical Sciences and Natural Products, School of Basic and Applied Sciences, Central University of Punjab, Bathinda 151 001, India
| | - Kamalpreet Kaur
- Department of Pharmaceutical Sciences and Natural Products, School of Basic and Applied Sciences, Central University of Punjab, Bathinda 151 001, India
| | - Vikas Jaitak
- Department of Pharmaceutical Sciences and Natural Products, School of Basic and Applied Sciences, Central University of Punjab, Bathinda 151 001, India.
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Frija LMT, Ntungwe E, Sitarek P, Andrade JM, Toma M, Śliwiński T, Cabral L, S. Cristiano ML, Rijo P, Pombeiro AJL. In Vitro Assessment of Antimicrobial, Antioxidant, and Cytotoxic Properties of Saccharin-Tetrazolyl and -Thiadiazolyl Derivatives: The Simple Dependence of the pH Value on Antimicrobial Activity. Pharmaceuticals (Basel) 2019; 12:E167. [PMID: 31726663 PMCID: PMC6958446 DOI: 10.3390/ph12040167] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 02/07/2023] Open
Abstract
The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin-tetrazolyl and -thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 µg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0-100 µg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.
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Affiliation(s)
- Luís M. T. Frija
- Centro de Química Estrutural (CQE), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
| | - Epole Ntungwe
- CBIOS—Research Center for Health Sciences & Technologies, ULusófona de Humanidades e Tecnologias, Campo Grande 376, 1749-024 Lisboa, Portugal; (E.N.); (J.M.A.)
| | - Przemysław Sitarek
- Department of Biology and Pharmaceutical Botany, Medical University of Lodz, Muszyńskiego Street 1, 90-151 Łódź, Poland;
| | - Joana M. Andrade
- CBIOS—Research Center for Health Sciences & Technologies, ULusófona de Humanidades e Tecnologias, Campo Grande 376, 1749-024 Lisboa, Portugal; (E.N.); (J.M.A.)
| | - Monika Toma
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-151 Lodz, Poland; (M.T.); (T.Ś.)
| | - Tomasz Śliwiński
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-151 Lodz, Poland; (M.T.); (T.Ś.)
| | - Lília Cabral
- Department of Chemistry and Pharmacy (FCT) and Center of Marine Sciences (CCMar), Universidade do Algarve, P-8005-039 Faro, Portugal; (L.C.); (M.L.S.C.)
| | - M. Lurdes S. Cristiano
- Department of Chemistry and Pharmacy (FCT) and Center of Marine Sciences (CCMar), Universidade do Algarve, P-8005-039 Faro, Portugal; (L.C.); (M.L.S.C.)
| | - Patrícia Rijo
- CBIOS—Research Center for Health Sciences & Technologies, ULusófona de Humanidades e Tecnologias, Campo Grande 376, 1749-024 Lisboa, Portugal; (E.N.); (J.M.A.)
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Armando J. L. Pombeiro
- Centro de Química Estrutural (CQE), Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
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Angiotensin Analogs with Divergent Bias Stabilize Distinct Receptor Conformations. Cell 2019; 176:468-478.e11. [PMID: 30639099 DOI: 10.1016/j.cell.2018.12.005] [Citation(s) in RCA: 172] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/13/2018] [Accepted: 12/04/2018] [Indexed: 01/14/2023]
Abstract
"Biased" G protein-coupled receptor (GPCR) agonists preferentially activate pathways mediated by G proteins or β-arrestins. Here, we use double electron-electron resonance spectroscopy to probe the changes that ligands induce in the conformational distribution of the angiotensin II type I receptor. Monitoring distances between 10 pairs of nitroxide labels distributed across the intracellular regions enabled mapping of four underlying sets of conformations. Ligands from different functional classes have distinct, characteristic effects on the conformational heterogeneity of the receptor. Compared to angiotensin II, the endogenous agonist, agonists with enhanced Gq coupling more strongly stabilize an "open" conformation with an accessible transducer-binding site. β-arrestin-biased agonists deficient in Gq coupling do not stabilize this open conformation but instead favor two more occluded conformations. These data suggest a structural mechanism for biased ligand action at the angiotensin receptor that can be exploited to rationally design GPCR-targeting drugs with greater specificity of action.
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11
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Takezako T, Unal H, Karnik SS, Node K. The non-biphenyl-tetrazole angiotensin AT 1 receptor antagonist eprosartan is a unique and robust inverse agonist of the active state of the AT 1 receptor. Br J Pharmacol 2018; 175:2454-2469. [PMID: 29570771 PMCID: PMC5980637 DOI: 10.1111/bph.14213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/26/2018] [Accepted: 03/06/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Conditions such as hypertension and renal allograft rejection are accompanied by chronic, agonist-independent, signalling by angiotensin II AT1 receptors. The current treatment paradigm for these diseases entails the preferred use of inverse agonist AT1 receptor blockers (ARBs). However, variability in the inverse agonist activities of common biphenyl-tetrazole ARBs for the active state of AT1 receptors often leads to treatment failure. Therefore, characterization of robust inverse agonist ARBs for the active state of AT1 receptors is necessary. EXPERIMENTAL APPROACH To identify the robust inverse agonist for active state of AT1 receptors and its molecular mechanism, we performed site-directed mutagenesis, competition binding assay, inositol phosphate production assay and molecular modelling for both ground-state wild-type AT1 receptors and active-state N111G mutant AT1 receptors. KEY RESULTS Although candesartan and telmisartan exhibited weaker inverse agonist activity for N111G- compared with WT-AT1 receptors, only eprosartan exhibited robust inverse agonist activity for both N111G- and WT- AT1 receptors. Specific ligand-receptor contacts for candesartan and telmisartan are altered in the active-state N111G- AT1 receptors compared with the ground-state WT-AT1 receptors, suggesting an explanation of their attenuated inverse agonist activity for the active state of AT1 receptors. In contrast, interactions between eprosartan and N111G-AT1 receptors were not significantly altered, and the inverse agonist activity of eprosartan was robust. CONCLUSIONS AND IMPLICATIONS Eprosartan may be a better therapeutic option than other ARBs. Comparative studies investigating eprosartan and other ARBs for the treatment of diseases caused by chronic, agonist-independent, AT1 receptor activation are warranted.
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Affiliation(s)
- Takanobu Takezako
- Department of Advanced Heart ResearchSaga UniversitySagaJapan
- Department of Internal MedicineNadeshiko Lady's HospitalKobeJapan
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research InstituteCleveland Clinic FoundationClevelandOHUSA
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research InstituteCleveland Clinic FoundationClevelandOHUSA
| | - Koichi Node
- Department of Cardiovascular MedicineSaga UniversitySagaJapan
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12
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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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13
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Sureshkumar K, Maheshwaran V, Dharma Rao T, Themmila K, Ponnuswamy M, Kadhirvel S, Dhandayutham S. Synthesis, characterization, crystal structure, in-vitro anti-inflammatory and molecular docking studies of 5-mercapto-1-substituted tetrazole incorporated quinoline derivative. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.05.085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Takezako T, Unal H, Karnik SS, Node K. Current topics in angiotensin II type 1 receptor research: Focus on inverse agonism, receptor dimerization and biased agonism. Pharmacol Res 2017. [PMID: 28648738 DOI: 10.1016/j.phrs.2017.06.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Although the octapeptide hormone angiotensin II (Ang II) regulates cardiovascular and renal homeostasis through the Ang II type 1 receptor (AT1R), overstimulation of AT1R causes various human diseases, such as hypertension and cardiac hypertrophy. Therefore, AT1R blockers (ARBs) have been widely used as therapeutic drugs for these diseases. Recent basic research and clinical studies have resulted in the discovery of interesting phenomena associated with AT1R function. For example, ligand-independent activation of AT1R by mechanical stress and agonistic autoantibodies, as well as via receptor mutations, has been shown to decrease the inverse agonistic efficacy of ARBs, though the molecular mechanisms of such phenomena had remained elusive until recently. Furthermore, although AT1R is believed to exist as a monomer, recent studies have demonstrated that AT1R can homodimerize and heterodimerize with other G-protein coupled receptors (GPCR), altering the receptor signaling properties. Therefore, formation of both AT1R homodimers and AT1R-GPCR heterodimer may be involved in the pathogenesis of human disease states, such as atherosclerosis and preeclampsia. Finally, biased AT1R ligands that can preferentially activate the β-arrestin-mediated signaling pathway have been discovered. Such β-arrestin-biased AT1R ligands may be better therapeutic drugs for cardiovascular diseases. New findings on AT1R described herein could provide a conceptual framework for application of ARBs in the treatment of diseases, as well as for novel drug development. Since AT1R is an extensively studied member of the GPCR superfamily encoded in the human genome, this review is relevant for understanding the functions of other members of this superfamily.
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Affiliation(s)
- Takanobu Takezako
- Department of Advanced Heart Research, Saga University, Saga, Japan; Medical Center for Student Health, Kobe University, Kobe, Japan.
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Koichi Node
- Department of Cardiovascular Medicine, Saga University, Japan
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15
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Movahedifar F, Modarresi-Alam AR, Kleinpeter E, Schilde U. Dynamic 1H-NMR study of unusually high barrier to rotation about the partial C N double bond in N,N-dimethyl carbamoyl 5-aryloxytetrazoles. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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16
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Wei L, Wang J, Zhang X, Wang P, Zhao Y, Li J, Hou T, Qu L, Shi L, Liang X, Fang Y. Discovery of 2H-Chromen-2-one Derivatives as G Protein-Coupled Receptor-35 Agonists. J Med Chem 2016; 60:362-372. [DOI: 10.1021/acs.jmedchem.6b01431] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lai Wei
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jixia Wang
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xiuli Zhang
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Co-innovation
Center of Neuroregeneration, Nantong University, Nantong 226019, China
| | - Ping Wang
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Yaopeng Zhao
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jiaqi Li
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Tao Hou
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Lala Qu
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Liying Shi
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Xinmiao Liang
- Key
Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Co-innovation
Center of Neuroregeneration, Nantong University, Nantong 226019, China
| | - Ye Fang
- Biochemical
Technologies, Science and Technology Division, Corning, New York 14831, United States
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17
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Farrokhzadeh A, Modarresi-Alam AR, Akher FB, Ebrahimi A. A theoretical study of π-stacking interactions in C-substituted tetrazoles. J Mol Graph Model 2016; 67:85-93. [PMID: 27258189 DOI: 10.1016/j.jmgm.2016.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 11/28/2022]
Abstract
The π-stacking effects of benzene ring (Ben) with 1H- and 2H-tetrazole derivatives (1H-TZ-X and 2H-TZ-X) substituted at C5 (where X is Cl, COH, NO, NO2, CN, NH2, OH, OCH3, SH and H) has been investigated by the quantum mechanical calculations at the M06-2X/6-311++G** level. The results indicate the 1H-TZ-X||Ben complexes (|| donates π-stacking interaction) are more stable than 2H-TZ-X||Ben while in unstacked forms, 1H-TZ-X is less stable than 2H-TZ-X. All substituents enhance the π-stacking interaction relative to the unsubstituted ones and enhancement is higher for the electron-withdrawing substituents (EWSs). Also, investigation of the local and direct effect of substituents in stacking interaction showed that all substituents regardless of whether are electron donating or electron withdrawing have an additive effect in π-stacking interaction. Excellent correlations were found between the binding energies of the complexes and combination of substituent constant terms. The results showed that the electrostatic interaction alone is not responsible for stacking stabilization but charge penetration is important. Furthermore, analysis of aromaticity, AIM, ESP and NPA were investigated to obtain aromaticity index, non-bonding interactions, chemical reactivity and polarity (dipole moment), respectively.
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Affiliation(s)
| | | | | | - Ali Ebrahimi
- Department of Chemistry, University of Sistan and Baluchestan, Zahedan, Iran
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18
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Martin RP, Filippelli-Silva R, Rodrigues ES, Nakaie CR, Shimuta SI. A fluorimetric binding assay for angiotensin II and kinin receptors. J Pharmacol Toxicol Methods 2016; 79:55-9. [PMID: 26802446 DOI: 10.1016/j.vascn.2016.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/22/2015] [Accepted: 01/15/2016] [Indexed: 11/18/2022]
Abstract
Angiotensin II (AngII) and kinins (bradykinin (BK) and des-Arg9-bradykinin (DBK)), are potent agents involved in the maintenance of blood pressure and several biological activities, and their better understanding is important to produce new drugs aimed to control arterial blood pressure. Previous studies on ligand-receptor binding have been based on radioactive methods, which led us to study a new method based on the fluorimetric method. A lanthanide attached to the N-terminal segment of the peptide (AngII, BK and DBK), which produces a time-resolved-fluorescent ligand, was used in a binding test with CHO cells expressing the AT1, AT2, B1 or B2 receptors in comparison with the same cell line tested with the radioactive ligand. Our findings indicated that the non-radioactive method provided a comparable result for the angiotensin receptors. On the other hand, the kinin receptors showed a slight reduction in the binding affinity, probably due to the linkage at the N-terminal segment and/or to the lower biological stability associated to the high temperature (37°C) used for the fluorimetric method, while the radioactive one was at 4°C. We can conclude that a time-resolved fluorescence assay would provide a sensitive method as an alternative tool for receptor studies.
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Affiliation(s)
- Renan P Martin
- Department of Biophysics, Federal University of São Paulo, 04023-062, Brazil.
| | | | - Eliete S Rodrigues
- Department of Biophysics, Federal University of São Paulo, 04023-062, Brazil
| | - Clovis R Nakaie
- Department of Biophysics, Federal University of São Paulo, 04023-062, Brazil
| | - Suma I Shimuta
- Department of Biophysics, Federal University of São Paulo, 04023-062, Brazil
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19
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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: 215] [Impact Index Per Article: 23.9] [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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20
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Takezako T, Unal H, Karnik SS, Node K. Structure-Function Basis of Attenuated Inverse Agonism of Angiotensin II Type 1 Receptor Blockers for Active-State Angiotensin II Type 1 Receptor. Mol Pharmacol 2015; 88:488-501. [PMID: 26121982 DOI: 10.1124/mol.115.099176] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/29/2015] [Indexed: 01/05/2023] Open
Abstract
Ligand-independent signaling by the angiotensin II type 1 receptor (AT1R) can be activated in clinical settings by mechanical stretch and autoantibodies as well as receptor mutations. Transition of the AT1R to the activated state is known to lower inverse agonistic efficacy of clinically used AT1R blockers (ARBs). The structure-function basis for reduced efficacy of inverse agonists is a fundamental aspect that has been understudied not only in relation to the AT1R but also regarding other homologous receptors. Here, we demonstrate that the active-state transition in the AT1R indeed attenuates an inverse agonistic effect of four biphenyl-tetrazole ARBs through changes in specific ligand-receptor interactions. In the ground state, tight interactions of four ARBs with a set of residues (Ser109(TM3), Phe182(ECL2), Gln257(TM6), Tyr292(TM7), and Asn295(TM7)) results in potent inverse agonism. In the activated state, the ARB-AT1R interactions shift to a different set of residues (Val108(TM3), Ser109(TM3), Ala163(TM4), Phe182(ECL2), Lys199(TM5), Tyr292(TM7), and Asn295(TM7)), resulting in attenuated inverse agonism. Interestingly, V108I, A163T, N295A, and F182A mutations in the activated state of the AT1R shift the functional response to the ARB binding toward agonism, but in the ground state the same mutations cause inverse agonism. Our data show that the second extracellular loop is an important regulator of the functional states of the AT1R. Our findings suggest that the quest for discovering novel ARBs, and improving current ARBs, fundamentally depends on the knowledge of the unique sets of residues that mediate inverse agonistic potency in the two states of the AT1R.
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Affiliation(s)
- Takanobu Takezako
- Department of Advanced Heart Research, Saga University, Saga, Japan (T.T.); Department of Cardiovascular Medicine, Saga University, Saga, Japan (K.N.); Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (H.U., S.S.K.); Department of Biosignal Pathophysiology, Kobe University Graduate School of Medicine, Kobe, Japan (T.T.); and Department of Basic Sciences, Faculty of Pharmacy and Betul Ziya Eren Genome and Stem Cell Center, Erciyes University, Kayseri, Turkey (H.U.)
| | - Hamiyet Unal
- Department of Advanced Heart Research, Saga University, Saga, Japan (T.T.); Department of Cardiovascular Medicine, Saga University, Saga, Japan (K.N.); Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (H.U., S.S.K.); Department of Biosignal Pathophysiology, Kobe University Graduate School of Medicine, Kobe, Japan (T.T.); and Department of Basic Sciences, Faculty of Pharmacy and Betul Ziya Eren Genome and Stem Cell Center, Erciyes University, Kayseri, Turkey (H.U.)
| | - Sadashiva S Karnik
- Department of Advanced Heart Research, Saga University, Saga, Japan (T.T.); Department of Cardiovascular Medicine, Saga University, Saga, Japan (K.N.); Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (H.U., S.S.K.); Department of Biosignal Pathophysiology, Kobe University Graduate School of Medicine, Kobe, Japan (T.T.); and Department of Basic Sciences, Faculty of Pharmacy and Betul Ziya Eren Genome and Stem Cell Center, Erciyes University, Kayseri, Turkey (H.U.)
| | - Koichi Node
- Department of Advanced Heart Research, Saga University, Saga, Japan (T.T.); Department of Cardiovascular Medicine, Saga University, Saga, Japan (K.N.); Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (H.U., S.S.K.); Department of Biosignal Pathophysiology, Kobe University Graduate School of Medicine, Kobe, Japan (T.T.); and Department of Basic Sciences, Faculty of Pharmacy and Betul Ziya Eren Genome and Stem Cell Center, Erciyes University, Kayseri, Turkey (H.U.)
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21
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Balakumar P, Jagadeesh G. Structural determinants for binding, activation, and functional selectivity of the angiotensin AT1 receptor. J Mol Endocrinol 2014; 53:R71-92. [PMID: 25013233 DOI: 10.1530/jme-14-0125] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The renin-angiotensin system (RAS) plays an important role in the pathophysiology of cardiovascular disorders. Pharmacologic interventions targeting the RAS cascade have led to the discovery of renin inhibitors, angiotensin-converting enzyme inhibitors, and AT(1) receptor blockers (ARBs) to treat hypertension and some cardiovascular and renal disorders. Mutagenesis and modeling studies have revealed that differential functional outcomes are the results of multiple active states conformed by the AT(1) receptor upon interaction with angiotensin II (Ang II). The binding of agonist is dependent on both extracellular and intramembrane regions of the receptor molecule, and as a consequence occupies more extensive area of the receptor than a non-peptide antagonist. Both agonist and antagonist bind to the same intramembrane regions to interfere with each other's binding to exhibit competitive, surmountable interaction. The nature of interactions with the amino acids in the receptor is different for each of the ARBs given the small differences in the molecular structure between drugs. AT(1) receptors attain different conformation states after binding various Ang II analogues, resulting in variable responses through activation of multiple signaling pathways. These include both classical and non-classical pathways mediated through growth factor receptor transactivations, and provide cross-communication between downstream signaling molecules. The structural requirements for AT(1) receptors to activate extracellular signal-regulated kinases 1 and 2 through G proteins, or G protein-independently through β-arrestin, are different. We review the structural and functional characteristics of Ang II and its analogs and antagonists, and their interaction with amino acid residues in the AT(1) receptor.
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Affiliation(s)
- Pitchai Balakumar
- Pharmacology UnitFaculty of Pharmacy, AIMST University, Semeling, 08100 Bedong, Kedah Darul Aman, MalaysiaDivision of Cardiovascular and Renal ProductsCenter for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland 20993, USA
| | - Gowraganahalli Jagadeesh
- Pharmacology UnitFaculty of Pharmacy, AIMST University, Semeling, 08100 Bedong, Kedah Darul Aman, MalaysiaDivision of Cardiovascular and Renal ProductsCenter for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland 20993, USA
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Tirupula KC, Desnoyer R, Speth RC, Karnik SS. Atypical signaling and functional desensitization response of MAS receptor to peptide ligands. PLoS One 2014; 9:e103520. [PMID: 25068582 PMCID: PMC4113456 DOI: 10.1371/journal.pone.0103520] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 07/01/2014] [Indexed: 11/19/2022] Open
Abstract
MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1-7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1-7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data suggest that peptide ligands induce atypical signaling and functional desensitization of MAS.
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Affiliation(s)
- Kalyan C. Tirupula
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Robert C. Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Sadashiva S. Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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Araujo-Andrade C, Reva I, Fausto R. Tetrazole acetic acid: Tautomers, conformers, and isomerization. J Chem Phys 2014; 140:064306. [DOI: 10.1063/1.4864119] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Meanwell NA. The Influence of Bioisosteres in Drug Design: Tactical Applications to Address Developability Problems. TACTICS IN CONTEMPORARY DRUG DESIGN 2014; 9. [PMCID: PMC7416817 DOI: 10.1007/7355_2013_29] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The application of bioisosteres in drug discovery is a well-established design concept that has demonstrated utility as an approach to solving a range of problems that affect candidate optimization, progression, and durability. In this chapter, the application of isosteric substitution is explored in a fashion that focuses on the development of practical solutions to problems that are encountered in typical optimization campaigns. The role of bioisosteres to affect intrinsic potency and selectivity, influence conformation, solve problems associated with drug developability, including P-glycoprotein recognition, modulating basicity, solubility, and lipophilicity, and to address issues associated with metabolism and toxicity is used as the underlying theme to capture a spectrum of creative applications of structural emulation in the design of drug candidates.
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Reassessment of the unique mode of binding between angiotensin II type 1 receptor and their blockers. PLoS One 2013; 8:e79914. [PMID: 24260317 PMCID: PMC3832659 DOI: 10.1371/journal.pone.0079914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 09/25/2013] [Indexed: 11/30/2022] Open
Abstract
While the molecular structures of angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) are very similar, they are also slightly different. Although each ARB has been shown to exhibit a unique mode of binding to AT1 receptor, different positions of the AT1 receptor have been analyzed and computational modeling has been performed using different crystal structures for the receptor as a template and different kinds of software. Therefore, we systematically analyzed the critical positions of the AT1 receptor, Tyr113, Tyr184, Lys199, His256 and Gln257 using a mutagenesis study, and subsequently performed computational modeling of the binding of ARBs to AT1 receptor using CXCR4 receptor as a new template and a single version of software. The interactions between Tyr113 in the AT1 receptor and the hydroxyl group of olmesartan, between Lys199 and carboxyl or tetrazole groups, and between His256 or Gln257 and the tetrazole group were studied. The common structure, a tetrazole group, of most ARBs similarly bind to Lys199, His256 and Gln257 of AT1 receptor. Lys199 in the AT1 receptor binds to the carboxyl group of EXP3174, candesartan and azilsartan, whereas oxygen in the amidecarbonyl group of valsartan may bind to Lys199. The benzimidazole portion of telmisartan may bind to a lipophilic pocket that includes Tyr113. On the other hand, the n-butyl group of irbesartan may bind to Tyr113. In conclusion, we confirmed that the slightly different structures of ARBs may be critical for binding to AT1 receptor and for the formation of unique modes of binding.
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Matsoukas MT, Potamitis C, Plotas P, Androutsou ME, Agelis G, Matsoukas J, Zoumpoulakis P. Insights into AT1 receptor activation through AngII binding studies. J Chem Inf Model 2013; 53:2798-811. [PMID: 24053563 DOI: 10.1021/ci4003014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study investigates the binding of angiotensin II (AngII) to the angiotensin II type 1 receptor (AT1R), taking into consideration several known activation elements that have been observed for G-protein-coupled receptors (GPCRs). In order to determine the crucial interactions of AngII upon binding, several MD simulations were implemented using AngII conformations derived from experimental data (NMR ROEs) and in silico flexible docking methodologies. An additional goal was to simulate the induced activation mechanism and examine the already known structural rearrangements of GPCRs upon activation. Performing MD simulations to the AT1R - AngII - lipids complex, a series of dynamic changes in the topology of AngII and the intracellular part of the receptor were observed. Overall, the present study proposes a complete binding profile of AngII to the AT1R, as well as the key transitional elements of the receptor and the agonist peptide upon activation through NMR and in silico studies.
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Affiliation(s)
- Minos-Timotheos Matsoukas
- Laboratori de Medicina Computacional, Unitat de Bioestadıstica, Facultat de Medicina, Universitat Autonoma de Barcelona , E-08193, Bellaterra, Barcelona, Spain
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27
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Theoretical studies on the tautomerism of tetrazole selenone. J Mol Model 2013; 19:4377-86. [PMID: 23912338 DOI: 10.1007/s00894-013-1941-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
The tautomerism of all possible forms of tetrazole selenone (A-G), induced by proton transfer, was studied, theoretically, in different environments including gas phase, continuum solvent and microsolvated environment with one or two explicit water or ammonia molecules. The calculations were performed using two different levels of theory including mPW2PLYP and DFT-B3LYP. The 6-311++G(d,p) basis set was used for C, H, O and N and the standard relativistic effective core pseudo potential LANL2DZ basis set was used for Se atom. It was found that the tetrazole selenone, in the form of A, is the most stable isomer in all of the environments considered in this work. The kinetics of proton transfer reaction was studied in both gas and solvent environments and it was concluded that the activation energy of the reaction increases with going from the gas phase to polar solvents. Moreover, the proton transfer reaction assisted by one or two water or ammonia molecules was investigated and it was found that the activation energy significantly reduces.
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Daze KD, Hof F. The cation-π interaction at protein-protein interaction interfaces: developing and learning from synthetic mimics of proteins that bind methylated lysines. Acc Chem Res 2013; 46:937-45. [PMID: 22724379 DOI: 10.1021/ar300072g] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
First discovered over 60 years ago, post-translational methylation was considered an irreversible modification until the initial discoveries of demethylase enzymes in 2004. Now researchers understand that this process serves as a dynamic and complex control mechanism that is misregulated in numerous diseases. Lysine methylation is most often found on histone proteins and can effect gene regulation, epigenetic inheritance, and cancer. Because of this connection to disease, many enzymes responsible for methylation are considered targets for new cancer therapies. Although our understanding of the biology of post-translational methylation has advanced at an astonishing rate within the last 5 years, chemical approaches for studying and disrupting these pathways are only now gaining momentum. In general, enzymes methylate lysine and arginine residues with very high specificity for both the location and methylation state. Each methylated target serves as the focused hot spot for an inducible protein-protein interaction (PPI). Conceptually, lysine or arginine methylation is a subtle modification that leads to no change in charge and small changes in size, but it significantly alters the hydration energies and hydrogen bonding potential of these side chains. Nature has evolved a special motif for recognizing the methylation states of lysine, called the "aromatic cage", a collection of aromatic protein residues, often accompanied by one or more neighboring anionic residues. The combination of favorable cation-π, electrostatic, and van der Waals interactions, as well as size matching, gives these proteins a high degree of specificity for the methylation state. This Account summarizes the development of various supramolecular host system scaffolds developed to recognize and bind to ammonium cations, such as trimethyllysine, on the basis of their methylation state. Early systems bound to their targets in pure, buffered water but failed to achieve biochemically relevant affinities and selectivities. Surprisingly, the use of the simple and very well-known p-sulfonatocalix[4]arene provides protein-like affinities and selectivities for trimethyllysine in water. New analogs, created by synthetic modification of the same scaffold, allow for further tuning of affinities and selectivities for trimethyllysine. Our studies of each family of hosts paint a consistent picture: cation-π interactions and electrostatics are important, and solvation effects are complex. Rigidity is especially important for host-guest systems that function in pure water. Despite their simplicity, synthetic systems that take these lessons into account can achieve affinities that rival or surpass those of their naturally evolved counterparts. The stage is now set for the next act: the use of such compounds as tunable and adaptable tools for modern chemical biology.
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Affiliation(s)
- Kevin D. Daze
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8W 3V6, Canada
| | - Fraser Hof
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8W 3V6, Canada
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Nistala R, Andresen BT, Pulakat L, Meuth A, Sinak C, Mandavia C, Thekkumkara T, Speth RC, Whaley-Connell A, Sowers JR. Angiotensin type 1 receptor resistance to blockade in the opossum proximal tubule cell due to variations in the binding pocket. Am J Physiol Renal Physiol 2013; 304:F1105-13. [PMID: 23389452 PMCID: PMC3625841 DOI: 10.1152/ajprenal.00127.2012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 01/31/2013] [Indexed: 01/13/2023] Open
Abstract
Blockade of the angiotensin (ANG) II receptor type 1 (AT(1)R) with angiotensin receptor blockers (ARBs) is widely used in the treatment of hypertension. However, ARBs are variably effective in reducing blood pressure, likely due, in part, to polymorphisms in the ARB binding pocket of the AT(1)R. Therefore, we need a better understanding of variations/polymorphisms that alter binding of ARBs in heterogeneous patient populations. The opossum proximal tubule cell (OKP) line is commonly used in research to evaluate renal sodium handling and therefore blood pressure. Investigating this issue, we found natural sequence variations in the opossum AT(1)R paralleling those observed in the human AT(1)R. Therefore, we posited that these sequence variations may explain ARB resistance. We demonstrate that OKP cells express AT(1)R mRNA, bind (125)I-labeled ANG II, and exhibit ANG II-induced phosphorylation of Jak2. However, Jak2 phosphorylation is not inhibited by five different ARBs commonly used to treat hypertension. Additionally, nonradioactive ANG II competes (125)I-ANG II efficiently, whereas a 10-fold molar excess of olmesartan and the ANG II receptor type 2 blocker PD-123319 is unable to block (125)I-ANG II binding. In contrast, ANG II binding to OKP cells stably expressing rat AT(1A)Rs, which have a conserved AT(1)R-binding pocket with human AT(1)R, is efficiently inhibited by olmesartan. A novel observation was that resistance to ARB binding to opossum AT(1)Rs correlates with variations from the human receptor at positions 108, 163, 192, and 198 within the ARB-binding pocket. These observations highlight the potential utility of evaluating AT(1)R polymorphisms within the ARB-binding pocket in various hypertensive populations.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Binding Sites
- Cell Line
- Drug Resistance/genetics
- Humans
- Imidazoles/pharmacology
- Iodine Radioisotopes
- Janus Kinase 2/metabolism
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/drug effects
- Opossums/genetics
- Phylogeny
- Polymorphism, Genetic/genetics
- Protein Structure, Secondary
- Protein Structure, Tertiary
- RNA, Messenger/genetics
- Rats
- Receptor, Angiotensin, Type 1/chemistry
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Species Specificity
- Tetrazoles/pharmacology
- Vasoconstrictor Agents/metabolism
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Ravi Nistala
- Division of Nephrology, Department of Internal Medicine, University of Missouri-Columbia, Columbia, MO 65212, USA
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Abstract
The carboxylic acid functional group can be an important constituent of a pharmacophore, however, the presence of this moiety can also be responsible for significant drawbacks, including metabolic instability, toxicity, as well as limited passive diffusion across biological membranes. To avoid some of these shortcomings while retaining the desired attributes of the carboxylic acid moiety, medicinal chemists often investigate the use of carboxylic acid (bio)isosteres. The same type of strategy can also be effective for a variety other purposes, for example, to increase the selectivity of a biologically active compound or to create new intellectual property. Several carboxylic acid isosteres have been reported, however, the outcome of any isosteric replacement cannot be readily predicted as this strategy is generally found to be dependent upon the particular context (i.e., the characteristic properties of the drug and the drug-target). As a result, screening of a panel of isosteres is typically required. In this context, the discovery and development of novel carboxylic acid surrogates that could complement the existing palette of isosteres remains an important area of research. The goal of this Minireview is to provide an overview of the most commonly employed carboxylic acid (bio)isosteres and to present representative examples demonstrating the use and utility of each isostere in drug design.
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Affiliation(s)
- Carlo Ballatore
- Department of Chemistry, University of Pennsylvania, 231 South 34th St., Philadelphia, PA 19104, USA.
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31
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Rodrigues ES, Martin RP, Silva RF, Nakaie CR, Oliveira L, Shimuta SI. Binding affinities and activation of Asp712Ala and Cys100Ser mutated kinin B1 receptor forms suggest a bimodal scheme for the molecule of bound-DABK. REGULATORY PEPTIDES 2013; 181:37-44. [PMID: 23318500 DOI: 10.1016/j.regpep.2012.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/30/2012] [Accepted: 12/17/2012] [Indexed: 06/01/2023]
Abstract
Mutant forms of kinin B(1) receptor (B(1)R) and analogs of the full agonist des-Arg(9)-bradykinin (DABK) were investigated aiming to verify the importance of selected receptor residues and of each agonist-peptide residue in the specific binding and activation. Linked by a specific disulfide bond (Cys(100)-Cys(650)), the N-terminal (N(t)) and the EC3 loop C-terminal (C(t)) segments of angiotensin II (AngII) receptor 1 (AT(1)R) have been identified to form an extracellular site for binding the agonist N(t) segment (Asp(1) and Arg(2) residues). Asp(712) residue at the receptor EC3 loop binds the peptide Arg(2) residue. By homology, a similar site might be considered for DABK binding to B(1)R since this receptor contains the same structural elements for composing the site in AT(1)R, namely the disulfide bond and the EC3 loop Asp(712) residue. DABK, Ala(n)-DABK analogs (n=Ala(1)-, Ala(2)-, Ala(3)-, Ala(4)-, Ala(5)-, Ala(6)-, Ala(7)-, Ala(8)-DABK), and other analogs were selected to binding wild-type, Asp712Ala and Cys100Ser mutated B(1)R receptors. The results obtained suggested that the same bimodal scheme adopted for AngII-AT(1)R system may be applied to DABK binding to B(1)R. The most crucial similarity in the two cases is that the N(t) segments of peptides equally bind to the homologous Asp(712) residue of both AT(1)R and B(1)R extracellular sites. Confirming this preliminary supposition, mutation of residues located at the B(1)R extracellular site as EC3 loop Asp(712) and Cys(100) caused the same modifications in biological assays observed in AT(1)R submitted to homologous mutations, such as significant weakening of agonist binding and reduction of post-receptor-activation processes. These findings provided enough support for defining a site that determines the specific binding of DABK to B(1)R receptors.
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Affiliation(s)
- E S Rodrigues
- Biophysics Department, Universidade Federal de São Paulo, Rua Botucatu, 862 7th floor, São Paulo, SP, Brazil
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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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Bhatnagar A, Unal H, Jagannathan R, Kaveti S, Duan ZH, Yong S, Vasanji A, Kinter M, Desnoyer R, Karnik SS. Interaction of G-protein βγ complex with chromatin modulates GPCR-dependent gene regulation. PLoS One 2013; 8:e52689. [PMID: 23326349 PMCID: PMC3541368 DOI: 10.1371/journal.pone.0052689] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 11/19/2012] [Indexed: 11/21/2022] Open
Abstract
Heterotrimeric G-protein signal transduction initiated by G-protein-coupled receptors (GPCRs) in the plasma membrane is thought to propagate through protein-protein interactions of subunits, Gα and Gβγ in the cytosol. In this study, we show novel nuclear functions of Gβγ through demonstrating interaction of Gβ2 with integral components of chromatin and effects of Gβ2 depletion on global gene expression. Agonist activation of several GPCRs including the angiotensin II type 1 receptor specifically augmented Gβ2 levels in the nucleus and Gβ2 interacted with specific nucleosome core histones and transcriptional modulators. Depletion of Gβ2 repressed the basal and angiotensin II-dependent transcriptional activities of myocyte enhancer factor 2. Gβ2 interacted with a sequence motif that was present in several transcription factors, whose genome-wide binding accounted for the Gβ2-dependent regulation of approximately 2% genes. These findings suggest a wide-ranging mechanism by which direct interaction of Gβγ with specific chromatin bound transcription factors regulates functional gene networks in response to GPCR activation in cells.
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Affiliation(s)
- Anushree Bhatnagar
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Rajaganapathi Jagannathan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Suma Kaveti
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Zhong-Hui Duan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Computer Science, University of Akron, Akron, Ohio, United States of America
| | - Sandro Yong
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Amit Vasanji
- Biomedical Imaging and Analysis Core, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Michael Kinter
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Russell Desnoyer
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Sadashiva S. Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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Arao T, Okada Y, Mori H, Nishida K, Tanaka Y. Antihypertensive and metabolic effects of high-dose olmesartan and telmisartan in type 2 diabetes patients with hypertension. Endocr J 2013; 60:563-70. [PMID: 23303198 DOI: 10.1507/endocrj.ej12-0326] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We performed a crossover study in hypertensive patients with type 2 diabetes to compare olmesartan (40 mg/day) with telmisartan (80 mg/day) in terms of their antihypertensive and metabolic effects. The subjects were 36 patients (20 men and 16 women) with type 2 diabetes who did not achieve a blood pressure <130/80 mmHg following treatment with olmesartan at 40 mg/day or telmisartan at 80 mg/day for 8 weeks or more. The primary endpoint was the blood pressure reduction rate, while the secondary endpoints were BMI, parameters of glucose metabolism, HMW-adiponectin, hs-CRP and lipids metabolism. All parameters were measured in Weeks 0, 12, and 24. Treatments were switched in Week 0, and Week 12 and the following results were obtained. There were 1) no significant differences in baseline characteristics; 2) no significant difference of the blood pressure reduction rate; 3) significant reductions of HbA1c (NGSP), FPG and HOMA-IR in olmesartan group; 4) a significant increase of HDL-C in olmesartan group; 5) a decrease of hs-CRP and a increase of HMW-adiponectin in olmesartan group; and 6) a positive correlation between the percent changes of HOMA-IR and hs-CRP in olmesartan group. In conclusion, there was no difference of the blood pressure reduction achieved at the highest dose in olmesartan group and telmisartan group. But improvement of glycemic control and insulin resistance was only observed in olmesartan group. Because there was a correlation between the percent changes of HOMA-IR and hs-CRP, these effects of olmesartan might be mediated by an anti-inflammatory action.
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Affiliation(s)
- Tadashi Arao
- The First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
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Dragun D, Catar R, Kusch A, Heidecke H, Philippe A. Non-HLA-antibodies targeting Angiotensin type 1 receptor and antibody mediated rejection. Hum Immunol 2012; 73:1282-6. [DOI: 10.1016/j.humimm.2012.07.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/14/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022]
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36
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Miura SI, Okabe A, Matsuo Y, Karnik SS, Saku K. Unique binding behavior of the recently approved angiotensin II receptor blocker azilsartan compared with that of candesartan. Hypertens Res 2012; 36:134-9. [PMID: 23034464 DOI: 10.1038/hr.2012.147] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The angiotensin II type 1 (AT(1)) receptor blocker (ARB) candesartan strongly reduces blood pressure (BP) in patients with hypertension and has been shown to have cardioprotective effects. A new ARB, azilsartan, was recently approved and has been shown to provide a more potent 24-h sustained antihypertensive effect than candesartan. However, the molecular interactions of azilsartan with the AT(1) receptor that could explain its strong BP-lowering activity are not yet clear. To address this issue, we examined the binding affinities of ARBs for the AT(1) receptor and their inverse agonist activity toward the production of inositol phosphate (IP), and we constructed docking models for the interactions between ARBs and the receptor. Azilsartan, unlike candesartan, has a unique moiety, a 5-oxo-1,2,4-oxadiazole, in place of a tetrazole ring. Although the results regarding the binding affinities of azilsartan and candesartan demonstrated that these ARBs interact with the same sites in the AT(1) receptor (Tyr(113), Lys(199) and Gln(257)), the hydrogen bonding between the oxadiazole of azilsartan-Gln(257) is stronger than that between the tetrazole of candesartan-Gln(257), according to molecular docking models. An examination of the inhibition of IP production by ARBs using constitutively active mutant receptors indicated that inverse agonist activity required azilsartan-Gln(257) interaction and that azilsartan had a stronger interaction with Gln(257) than candesartan. Thus, we speculate that azilsartan has a unique binding behavior to the AT(1) receptor due to its 5-oxo-1,2,4-oxadiazole moiety and induces stronger inverse agonism. This property of azilsartan may underlie its previously demonstrated superior BP-lowering efficacy compared with candesartan and other ARBs.
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, Japan.
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37
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Moitra S, Tirupula KC, Klein-Seetharaman J, Langmead CJ. A minimal ligand binding pocket within a network of correlated mutations identified by multiple sequence and structural analysis of G protein coupled receptors. BMC BIOPHYSICS 2012; 5:13. [PMID: 22748306 PMCID: PMC3478154 DOI: 10.1186/2046-1682-5-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/21/2012] [Indexed: 01/07/2023]
Abstract
Background G protein coupled receptors (GPCRs) are seven helical transmembrane proteins that function as signal transducers. They bind ligands in their extracellular and transmembrane regions and activate cognate G proteins at their intracellular surface at the other side of the membrane. The relay of allosteric communication between the ligand binding site and the distant G protein binding site is poorly understood. In this study, GREMLIN
[1], a recently developed method that identifies networks of co-evolving residues from multiple sequence alignments, was used to identify those that may be involved in communicating the activation signal across the membrane. The GREMLIN-predicted long-range interactions between amino acids were analyzed with respect to the seven GPCR structures that have been crystallized at the time this study was undertaken. Results GREMLIN significantly enriches the edges containing residues that are part of the ligand binding pocket, when compared to a control distribution of edges drawn from a random graph. An analysis of these edges reveals a minimal GPCR binding pocket containing four residues (T1183.33, M2075.42, Y2686.51 and A2927.39). Additionally, of the ten residues predicted to have the most long-range interactions (A1173.32, A2726.55, E1133.28, H2115.46, S186EC2, A2927.39, E1223.37, G902.57, G1143.29 and M2075.42), nine are part of the ligand binding pocket. Conclusions We demonstrate the use of GREMLIN to reveal a network of statistically correlated and functionally important residues in class A GPCRs. GREMLIN identified that ligand binding pocket residues are extensively correlated with distal residues. An analysis of the GREMLIN edges across multiple structures suggests that there may be a minimal binding pocket common to the seven known GPCRs. Further, the activation of rhodopsin involves these long-range interactions between extracellular and intracellular domain residues mediated by the retinal domain.
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Affiliation(s)
- Subhodeep Moitra
- Computer Science Department, Carnegie Mellon University, Gates Hillman Center, 5000 Forbes Avenue, Pittsburgh, PA, USA
| | - Kalyan C Tirupula
- Department of Structural Biology, University of Pittsburgh School of Medicine, Rm. 2051, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, USA
| | - Judith Klein-Seetharaman
- Department of Structural Biology, University of Pittsburgh School of Medicine, Rm. 2051, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA, USA
| | - Christopher James Langmead
- Computer Science Department, Carnegie Mellon University, Gates Hillman Center, 5000 Forbes Avenue, Pittsburgh, PA, USA
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Abstract
Constitutively active mutants (CAMs) of G-protein-coupled receptors mimic the active conformation of the receptor in their ability to activate second messenger systems in the absence of agonist. They have revealed novel properties of drugs that reverse the basal levels of constitutive activity, indicating that the drugs have the inverse agonist activity. Internalization plays an important role in receptor endocytosis and signal transduction. The present chapter provides the investigation of the internalization behavior of CAM N111G of Angiotensin II type 1 (AT(1)) receptor and correlates the result with the mechanism of constitutive activity of the mutant. Both wild-type (WT) and N111G mutant receptors were transiently expressed in COS-7 cells and total inositol phosphate production was measured in presence and absence of the angiotensin II receptor blockers (ARBs). The binding affinities toward agonist and ARBs were also determined. We found that the ARBs have the inverse agonist activity in CAM N111G of AT(1) receptor. The internalization of the mutant, which was much lower than WT receptor, was significantly increased in presence of the ARBs. The results indicate that internalization of CAM N111G of AT(1) receptor is induced by the ARBs, which may be an important characteristic of inverse agonist activities of the ARBs in N111G.
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Synthesis of selected 5-thio-substituted tetrazole derivatives and evaluation of their antibacterial and antifungal activities. JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2011. [DOI: 10.2298/jsc090421001d] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Several 5-thio-substituted tetrazole derivatives were efficiently
synthesized by a three-step process. The substituted tetrazol-5-thiol,
namely, 1-benzyl-1H-tetrazol-5-thiol (2) was prepared by refluxing
commercially available benzyl isothiocyanate (1) with sodium azide in water.
The second step was the synthesis of 1-benzyl-5-[(3-bromopropyl)
thio]tetrazole (3) by thio alkylation of tetrazol-5-thiol (2) with 1,3-
dibromopropane in tetrahydrofuran. Finally, the 5-thio-substituted tetrazole
derivatives 4a-i were prepared by condensation of (3) with the corresponding
amine or thiol. The structures of the newly synthesized compounds were
characterized by NMR, LC/MS/MS, IR spectral data and elemental analysis. All
the synthesized compounds were screened for their antibacterial and
antifungal activities.
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A small difference in the molecular structure of angiotensin II receptor blockers induces AT₁ receptor-dependent and -independent beneficial effects. Hypertens Res 2010; 33:1044-52. [PMID: 20668453 DOI: 10.1038/hr.2010.135] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Angiotensin II (Ang II) type 1 (AT₁) receptor blockers (ARBs) induce multiple pharmacological beneficial effects, but not all ARBs have the same effects and the molecular mechanisms underlying their actions are not certain. In this study, irbesartan and losartan were examined because of their different molecular structures (irbesartan has a cyclopentyl group whereas losartan has a chloride group). We analyzed the binding affinity and production of inositol phosphate (IP), monocyte chemoattractant protein-1 (MCP-1) and adiponectin. Compared with losartan, irbesartan showed a significantly higher binding affinity and slower dissociation rate from the AT₁ receptor and a significantly higher degree of inverse agonism and insurmountability toward IP production. These effects of irbesartan were not seen with the AT₁-Y113A mutant receptor. On the basis of the molecular modeling of the ARBs-AT₁ receptor complex and a mutagenesis study, the phenyl group at Tyr(113) in the AT₁ receptor and the cyclopentyl group of irbesartan may form a hydrophobic interaction that is stronger than the losartan-AT₁ receptor interaction. Interestingly, irbesartan inhibited MCP-1 production more strongly than losartan. This effect was mediated by the inhibition of nuclear factor-kappa B activation that was independent of the AT₁ receptor in the human coronary endothelial cells. In addition, irbesartan, but not losartan, induced significant adiponectin production that was mediated by peroxisome proliferator-activated receptor-γ activation in 3T3-L1 adipocytes, and this effect was not mediated by the AT₁ receptor. In conclusion, irbesartan induced greater beneficial effects than losartan due to small differences between their molecular structures, and these differential effects were both dependent on and independent of the AT₁ receptor.
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Miura SI, Karnik SS, Saku K. Review: angiotensin II type 1 receptor blockers: class effects versus molecular effects. J Renin Angiotensin Aldosterone Syst 2010; 12:1-7. [PMID: 20603272 DOI: 10.1177/1470320310370852] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Highly selective angiotensin II (Ang II) type 1 (AT(1)) receptor blockers (ARBs) are now available. The AT(1) receptor is a member of the G protein-coupled receptor (GPCR) superfamily and block the diverse effects of Ang II. Several ARBs are available for clinical use. Most ARBs have common molecular structures (biphenyl-tetrazol and imidazole groups) and it is clear that ARBs have 'class effects'. On the other hand, recent clinical studies have demonstrated that not all ARBs have the same effects, and some benefits conferred by ARBs may not be class effects, and instead may be 'molecular effects'. In addition, each ARB has been clearly shown to have specific molecular effects in basic experimental studies, and these effects may be due to small differences in the molecular structure of each ARB. However, it is controversial whether ARBs have molecular effects in a clinical setting. Although the presence of molecular effects for each ARB based on experimental studies may not directly influence the clinical outcome, this possibility has not been adequately evaluated. This review focuses on the class effects versus molecular effects of ARBs from bench to bedside.
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Affiliation(s)
- Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan.
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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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Frija LMT, Ismael A, Cristiano MLS. Photochemical transformations of tetrazole derivatives: applications in organic synthesis. Molecules 2010; 15:3757-74. [PMID: 20657512 PMCID: PMC6257500 DOI: 10.3390/molecules15053757] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/01/2010] [Accepted: 05/21/2010] [Indexed: 11/19/2022] Open
Abstract
Tetrazoles remain a challenge to photochemists. Photolysis leads to cleavage of the tetrazolyl ring, may involve various photodegradation pathways and may produce a diversity of photoproducts, depending on the structure and conformational flexibility of the substituents and the possibility of tautomerism. If the photochemistry of tetrazoles is considered within the frame of synthetic applications the subject is even more challenging, since the ultimate goal is to achieve selectivity and high yield. In addition, the photoproducts must remain stable and allow isolation or trapping, in order to be used in other reactions. This review summarises the photochemical transformations of tetrazole derivatives that can be used as effective synthetic routes to other compounds.
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Affiliation(s)
- Luís Miguel Teodoro Frija
- CQFM - Centro de Química-Física Molecular, IN - Institute of Nanoscience and Nanotechnology, Departamento de Engenharia Química e Biológica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal; E-Mail: (L.M.T.F.)
| | - Amin Ismael
- Departmento de Química e Farmácia, FCT, and CCMAR, Universidade do Algarve, Campus de Gambelas, 8005-039 Faro, Portugal
| | - Maria Lurdes Santos Cristiano
- Departmento de Química e Farmácia, FCT, and CCMAR, Universidade do Algarve, Campus de Gambelas, 8005-039 Faro, Portugal
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +351-289-800-100; Fax: +351-289-819-403
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de Noronha SMR, Corrêa SAA, Poletti EF, Lopes DD, da Silva CC, Sforça ML, Shimuta SI, Zanchin NIT, Nakaie CR, da Silva IDCG. Structural analysis of three peptides related to the transmambranic helix VI of AT1 receptor. Neuropeptides 2010; 44:115-8. [PMID: 20006383 DOI: 10.1016/j.npep.2009.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Angiotensin II (AII) is the main active product of the renin angiotensin system. Better known effects of AII are via AT1 receptor (AT1R). Expression of AT1R mutants (L265D and L262D) in CHO cells increased cAMP formation when compared to CHO cells expressing the wild type (WT) AT1R. Morphological transformation of CHO cells transfected with mutants correlated with their increased cAMP formation. DNA synthesis was inhibited in these cells too, indicating that cAMP promotes inhibitory effects on transfected CHO cells growth and causes their morphological change from a tumorigenic phenotype to a non-tumorigenic one. OBJECTIVES To assess the importance of leucine 262 and 265 in determining AT1R structure by means of a comparative structural analysis of two mutant peptides and of a wild-type fragment. METHODOLOGY Three peptides had their conformation compared by circular dichroism (CD): L262D(259-272), L265D(259-272) (mutants) and WT(260-277). RESULTS Secondary structures were: beta-turn for WT and L262D and random coil for L265D. CONCLUSIONS Strong correlation was found in the results of biochemical, cellular and structural approaches used to compare WT AT1R to mutant types. Random coil structure of the L265D mutant may be a key point to explain those changes observed in biochemical (binding and signal transduction) and proliferation assays (Correa et al., 2005). beta-Turn formation is an important step during early protein folding and this secondary simple structure is present in L262D and WT, but not in L265D. Therefore, leucine 265 seems to play a crucial role in determining an entirely functional AT1R.
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Affiliation(s)
- Samuel Marcos Ribeiro de Noronha
- Ginecologia Molecular/Ginecologia, UNIFESP-R. Pedro de Toledo, 791 - 4o. Andar, V. Clementino, CEP04039032 Sao Paulo, SP, Brazil.
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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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46
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Bhuiyan MA, Hossain M, Ishiguro M, Nakamura T, Nagatomo T. Engineered Mutation of Some Important Amino Acids in Angiotensin II Type 1 (AT1) Receptor Increases the Binding Affinity of AT1-Receptor Antagonists. J Pharmacol Sci 2010; 113:57-65. [DOI: 10.1254/jphs.09361fp] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Yan L, Holleran BJ, Lavigne P, Escher E, Guillemette G, Leduc R. Analysis of transmembrane domains 1 and 4 of the human angiotensin II AT1 receptor by cysteine-scanning mutagenesis. J Biol Chem 2009; 285:2284-93. [PMID: 19940150 DOI: 10.1074/jbc.m109.077180] [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) exerts a wide variety of cardiovascular effects through the activation of the AT(1) receptor, which belongs to the G protein-coupled receptor superfamily. Like other G protein-coupled receptors, the AT(1) receptor possesses seven transmembrane domains that provide structural support for the formation of the ligand-binding pocket. Here, we investigated the role of the first and fourth transmembrane domains (TMDs) in the formation of the binding pocket of the human AT(1) receptor using the substituted-cysteine accessibility method. Each residue within the Phe-28((1.32))-Ile-53((1.57)) fragment of TMD1 and Leu-143((4.40))-Phe-170((4.67)) fragment of TMD4 was mutated, one at a time, to a cysteine. The resulting mutant receptors 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 the binding affinity of TMD1 mutants M30C((1.34))-AT(1) and T33C((1.37))-AT(1) and TMD4 mutant V169C((4.66))-AT(1). Although this reduction in binding of the TMD1 mutants was maintained when examined in a constitutively active receptor (N111G-AT(1)) background, we found that V169C((4.66))-AT(1) remained unaffected when treated with MTSEA compared with untreated in this context. Moreover, the complete loss of binding observed for R167C((4.64))-AT(1) was restored upon treatment with MTSEA. Our results suggest that the extracellular portion of TMD1, particularly residues Met-30((1.34)) and Thr-33((1.37)), as well as residues Arg-167((4.64)) and Val-169((4.66)) at the junction of TMD4 and the second extracellular loop, are important binding determinants within the AT(1) receptor binding pocket but that these TMDs undergo very little movement, if at all, during the activation process.
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Affiliation(s)
- Liping Yan
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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Akazawa H, Yasuda N, Komuro I. Mechanisms and functions of agonist-independent activation in the angiotensin II type 1 receptor. Mol Cell Endocrinol 2009; 302:140-7. [PMID: 19059460 DOI: 10.1016/j.mce.2008.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 11/06/2008] [Accepted: 11/06/2008] [Indexed: 11/23/2022]
Abstract
The angiotensin II (AngII) type 1 (AT(1)) receptor is a seven-transmembrane G protein-coupled receptor, and is involved in regulating the physiological and pathological process of the cardiovascular system. Systemically and locally generated AngII has agonistic action on AT(1) receptor, but recent studies have demonstrated that AT(1) receptor inherently shows spontaneous activity even in the absence of AngII. Furthermore, mechanical stress can activate AT(1) receptor by inducing conformational switch without the involvement of AngII, and induce cardiac hypertrophy in vivo. These agonist-independent activities of AT(1) receptor can be inhibited by inverse agonists, but not by neutral antagonists. Considerable attention has been directed to molecular mechanisms and clinical implications of agonist-independent AT(1) receptor activation, and inverse agonist activity emerges as an important pharmacological parameter for AT(1) receptor blockers that will improve efficacy and expand therapeutic potentials in cardiovascular medicine.
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Affiliation(s)
- Hiroshi Akazawa
- Division of Cardiovascular Pathophysiology, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan
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Bhuiyan MA, Hossain M, Miura SI, Nakamura T, Ozaki M, Nagatomo T. Constitutively Active Mutant N111G of Angiotensin II Type 1 (AT1) Receptor Induces Homologous Internalization Through Mediation of AT1-Receptor Antagonist. J Pharmacol Sci 2009; 111:227-34. [DOI: 10.1254/jphs.09202fp] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Conformational switch of angiotensin II type 1 receptor underlying mechanical stress-induced activation. EMBO Rep 2008; 9:179-86. [PMID: 18202720 DOI: 10.1038/sj.embor.7401157] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 11/27/2007] [Accepted: 11/28/2007] [Indexed: 12/19/2022] Open
Abstract
The angiotensin II type 1 (AT(1)) receptor is a G protein-coupled receptor that has a crucial role in the development of load-induced cardiac hypertrophy. Here, we show that cell stretch leads to activation of the AT(1) receptor, which undergoes an anticlockwise rotation and a shift of transmembrane (TM) 7 into the ligand-binding pocket. As an inverse agonist, candesartan suppressed the stretch-induced helical movement of TM7 through the bindings of the carboxyl group of candesartan to the specific residues of the receptor. A molecular model proposes that the tight binding of candesartan to the AT(1) receptor stabilizes the receptor in the inactive conformation, preventing its shift to the active conformation. Our results show that the AT(1) receptor undergoes a conformational switch that couples mechanical stress-induced activation and inverse agonist-induced inactivation.
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