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Huck JD, Que NLS, Immormino RM, Shrestha L, Taldone T, Chiosis G, Gewirth DT. NECA derivatives exploit the paralog-specific properties of the site 3 side pocket of Grp94, the endoplasmic reticulum Hsp90. J Biol Chem 2019; 294:16010-16019. [PMID: 31501246 DOI: 10.1074/jbc.ra119.009960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/05/2019] [Indexed: 11/06/2022] Open
Abstract
The hsp90 chaperones govern the function of essential client proteins critical for normal cell function as well as cancer initiation and progression. Hsp90 activity is driven by ATP, which binds to the N-terminal domain and induces large conformational changes that are required for client maturation. Inhibitors targeting the ATP-binding pocket of the N-terminal domain have anticancer effects, but most bind with similar affinity to cytosolic Hsp90α and Hsp90β, endoplasmic reticulum Grp94, and mitochondrial Trap1, the four cellular hsp90 paralogs. Paralog-specific inhibitors may lead to drugs with fewer side effects. The ATP-binding pockets of the four paralogs are flanked by three side pockets, termed sites 1, 2, and 3, which differ between the paralogs in their accessibility to inhibitors. Previous insights into the principles governing access to sites 1 and 2 have resulted in development of paralog-selective inhibitors targeting these sites, but the rules for selective targeting of site 3 are less clear. Earlier studies identified 5'N-ethylcarboxamido adenosine (NECA) as a Grp94-selective ligand. Here we use NECA and its derivatives to probe the properties of site 3. We found that derivatives that lengthen the 5' moiety of NECA improve selectivity for Grp94 over Hsp90α. Crystal structures reveal that the derivatives extend further into site 3 of Grp94 compared with their parent compound and that selectivity is due to paralog-specific differences in ligand pose and ligand-induced conformational strain in the protein. These studies provide a structural basis for Grp94-selective inhibition using site 3.
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Affiliation(s)
- John D Huck
- Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203.,Department of Structural Biology, University at Buffalo, Buffalo, New York 14203
| | - Nanette L S Que
- Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203
| | | | - Liza Shrestha
- Memorial Sloan-Kettering Cancer Institute, New York, New York 10021
| | - Tony Taldone
- Memorial Sloan-Kettering Cancer Institute, New York, New York 10021
| | - Gabriela Chiosis
- Memorial Sloan-Kettering Cancer Institute, New York, New York 10021
| | - Daniel T Gewirth
- Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203 .,Department of Structural Biology, University at Buffalo, Buffalo, New York 14203
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Yu J, Zhao LX, Park J, Lee HW, Sahu PK, Cui M, Moss SM, Hammes E, Warnick E, Gao ZG, Noh M, Choi S, Ahn HC, Choi J, Jacobson KA, Jeong LS. N 6-Substituted 5'-N-Methylcarbamoyl-4'-selenoadenosines as Potent and Selective A 3 Adenosine Receptor Agonists with Unusual Sugar Puckering and Nucleobase Orientation. J Med Chem 2017; 60:3422-3437. [PMID: 28380296 DOI: 10.1021/acs.jmedchem.7b00241] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Potent and selective A3 adenosine receptor (AR) agonists were identified by the replacement of 4'-oxo- or 4'-thionucleosides with bioisosteric selenium. Unlike previous agonists, 4'-seleno analogues preferred a glycosidic syn conformation and South sugar puckering, as shown in the X-ray crystal structure of 5'-N-methylcarbamoyl derivative 3p. Among the compounds tested, N6-3-iodobenzyl analogue 3d was found to be the most potent A3AR full agonist (Ki = 0.57 nM), which was ≥800- and 1900-fold selective for A1AR and A2AAR, respectively. In the N6-cycloalkyl series, 2-Cl analogues generally exhibited better hA3AR affinity than 2-H analogues, whereas 2-H > 2-Cl in the N6-3-halobenzyl series. N7 isomers 3t and 3u were much weaker in binding than corresponding N9 isomers, but compound 3t lacked A3AR activation, appearing to be a weak antagonist. 2-Cl-N6-3-iodobenzyl analogue 3p inhibited chemoattractant-induced migration of microglia/monocytes without inducing cell death at ≤50 μM. This suggests the potential for the development of 4'-selenonucleoside A3AR agonists as novel antistroke agents.
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Affiliation(s)
- Jinha Yu
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea
| | - Long Xuan Zhao
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea.,College of Chemistry and Chemical Engineering, Liaoning Normal University , Dalian 116-029, China
| | - Jongmi Park
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University , Seoul 03760, Korea
| | - Hyuk Woo Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea
| | - Pramod K Sahu
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea
| | - Minghua Cui
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University , Seoul 03760, Korea
| | - Steven M Moss
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Eva Hammes
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Eugene Warnick
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Minsoo Noh
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea
| | - Sun Choi
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University , Seoul 03760, Korea
| | - Hee-Chul Ahn
- College of Pharmacy, Dongguk University , Goyang, Gyeonggi-do 410-820, Korea
| | - Jungwon Choi
- Department of Chemistry, The University of Suwon , Hwaseong, Gyeonggi-do 445-743, Korea
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, and Digestive and Kidney Disease, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Lak Shin Jeong
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 151-742, Korea
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Gewirth DT. Paralog Specific Hsp90 Inhibitors - A Brief History and a Bright Future. Curr Top Med Chem 2017; 16:2779-91. [PMID: 27072700 DOI: 10.2174/1568026616666160413141154] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/30/2015] [Accepted: 01/17/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND The high sequence and structural homology among the hsp90 paralogs - Hsp90α, Hsp90β, Grp94, and Trap-1 - has made the development of paralog-specific inhibitors a challenging proposition. OBJECTIVE This review surveys the state of developments in structural analysis, compound screening, and structure-based design that have been brought to bear on this problem. RESULTS First generation compounds that selectively bind to Hsp90, Grp94, or Trap-1 have been identified. CONCLUSION With the proof of principle firmly established, the prospects for further progress are bright.
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Affiliation(s)
- Daniel T Gewirth
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY, 14203, USA.
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4
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Harder M, Schäfer E, Kümin T, Illarionov B, Bacher A, Fischer M, Diederich F, Bernet B. 8-Substituted, syn-Configured Adenosine Derivatives as Potential Inhibitors of the Enzyme IspE from the Non-Mevalonate Pathway of Isoprenoid Biosynthesis. European J Org Chem 2015. [DOI: 10.1002/ejoc.201501150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Moukha-Chafiq O, Reynolds RC. Synthesis and general biological activity of a small adenosine-5'-(carboxamide and sulfanilamide) library. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2015; 33:709-29. [PMID: 25295748 DOI: 10.1080/15257770.2014.931588] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A small library of fifty-five adenosine peptide analogs was synthesized, under the Pilot Scale Library (PSL) Program of the NIH Roadmap initiative, from 2',3'-O-isopropylideneadenosine-5'-carboxylic acid 2. The coupling of amine or sulfanilamide reactants to the free 5'-carboxylic acid moiety of 2, in automated solution-phase fashion, led after acid-mediated hydrolysis to target compounds 3-57 in good yields and high purity. No marked anticancer or antimalarial activity was noted on preliminary cellular testing. Initial screening through the MLPCN program, however, indicates that these analogs may show diverse and interesting biological activities.
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Affiliation(s)
- Omar Moukha-Chafiq
- a Southern Research Institute , Drug Discovery Division , Birmingham , Alabama , USA
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6
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Moukha-Chafiq O, Reynolds RC. Synthesis of novel peptidyl adenosine antibiotic analogs. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2014; 33:53-63. [PMID: 24660880 DOI: 10.1080/15257770.2013.866243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A small library of peptidyl adenosine antibiotic analogs was synthesized, under the Pilot Scale Library Program of the NIH Roadmap initiative, from 2',3'-O-isoproylideneadenosine-5'-carboxylic acid 2 in excellent yield. The coupling of the amino terminus of L-2-aminophenylbutyric methyl ester to a free 5'-carboxylic acid moiety of 2 followed by sodium hydroxide treatment led to carboxylic acid analog 4. Hydrolysis of this latter gave unprotected nucleoside analog 5. Intermediate 4 served as the precursor for the preparation of novel peptidyl adenosine analogs 6-18 in good yields and high purity through peptide coupling reactions to diverse amine derivatives. No marked anticancer and antimalaria activity was noted on preliminary cellular testing; however these analogs should be useful candidates for other types of biological activity.
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Affiliation(s)
- Omar Moukha-Chafiq
- a Southern Research Institute, Drug Discovery Division , Birmingham , AL 35205 , USA
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7
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Moukha-chafiq O, Reynolds RC. Parallel solution-phase synthesis and general biological activity of a uridine antibiotic analog library. ACS COMBINATORIAL SCIENCE 2014; 16:232-7. [PMID: 24661222 PMCID: PMC4025591 DOI: 10.1021/co4001452] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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A small library of ninety four uridine antibiotic analogs was synthesized,
under the Pilot Scale Library (PSL) Program of the NIH Roadmap initiative,
from amine 2 and carboxylic acids 33 and 77 in solution-phase fashion. Diverse aldehyde, sulfonyl chloride,
and carboxylic acid reactant sets were condensed to 2, leading after acid-mediated hydrolysis, to the targeted compounds 3–32 in good yields and high purity. Similarly,
treatment of 33 with diverse amines and sulfonamides
gave 34–75. The coupling of the amino
terminus of d-phenylalanine methyl ester to the free 5′-carboxylic
acid moiety of 33 followed by sodium hydroxide treatment
led to carboxylic acid analog 77. Hydrolysis of this
material gave analog 78. The intermediate 77 served as the precursor for the preparation of novel dipeptidyl
uridine analogs 79–99 through peptide
coupling reactions to diverse amine reactants. None of the described
compounds show significant anticancer or antimalarial acivity. A number
of samples exhibited a variety of promising inhibitory, agonist, antagonist,
or activator properties with enzymes and receptors in primary screens
supplied and reported through the NIH MLPCN program.
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Affiliation(s)
- Omar Moukha-chafiq
- Southern Research Institute, Drug Discovery Division, Birmingham, Alabama 35205, United States
| | - Robert C. Reynolds
- Southern Research Institute, Drug Discovery Division, Birmingham, Alabama 35205, United States
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8
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de Lera Ruiz M, Lim YH, Zheng J. Adenosine A2A Receptor as a Drug Discovery Target. J Med Chem 2013; 57:3623-50. [DOI: 10.1021/jm4011669] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Manuel de Lera Ruiz
- Department
of Chemical Research, Merck Research Laboratories, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Yeon-Hee Lim
- Department
of Chemical Research, Merck Research Laboratories, 126 E. Lincoln Avenue, Rahway, New Jersey 07065, United States
| | - Junying Zheng
- Department
of Chemical Research, Merck Research Laboratories, 126 E. Lincoln Avenue, Rahway, New Jersey 07065, United States
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9
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Tosh DK, Phan K, Gao ZG, Gakh AA, Xu F, Deflorian F, Abagyan R, Stevens RC, Jacobson KA, Katritch V. Optimization of adenosine 5'-carboxamide derivatives as adenosine receptor agonists using structure-based ligand design and fragment screening. J Med Chem 2012; 55:4297-308. [PMID: 22486652 PMCID: PMC3479662 DOI: 10.1021/jm300095s] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Structures of G protein-coupled receptors (GPCRs) have a proven utility in the discovery of new antagonists and inverse agonists modulating signaling of this important family of clinical targets. Applicability of active-state GPCR structures to virtual screening and rational optimization of agonists, however, remains to be assessed. In this study of adenosine 5' derivatives, we evaluated the performance of an agonist-bound A(2A) adenosine receptor (AR) structure in retrieval of known agonists and then employed the structure to screen for new fragments optimally fitting the corresponding subpocket. Biochemical and functional assays demonstrate high affinity of new derivatives that include polar heterocycles. The binding models also explain modest selectivity gain for some substituents toward the closely related A(1)AR subtype and the modified agonist efficacy of some of these ligands. The study suggests further applicability of in silico fragment screening to rational lead optimization in GPCRs.
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Affiliation(s)
- Dilip K. Tosh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Khai Phan
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Andrei A. Gakh
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Fei Xu
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Francesca Deflorian
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Ruben Abagyan
- University of California, San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Raymond C. Stevens
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Vsevolod Katritch
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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10
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Shelton JR, Cutler CE, Oliveira M, Balzarini J, Peterson MA. Synthesis, SAR, and preliminary mechanistic evaluation of novel antiproliferative N6,5′-bis-ureido- and 5′-carbamoyl-N6-ureidoadenosine derivatives. Bioorg Med Chem 2012; 20:1008-19. [DOI: 10.1016/j.bmc.2011.11.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 11/19/2011] [Accepted: 11/19/2011] [Indexed: 01/26/2023]
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11
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Jaakola VP, Lane JR, Lin JY, Katritch V, Ijzerman AP, Stevens RC. Ligand binding and subtype selectivity of the human A(2A) adenosine receptor: identification and characterization of essential amino acid residues. J Biol Chem 2010; 285:13032-44. [PMID: 20147292 DOI: 10.1074/jbc.m109.096974] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The crystal structure of the human A(2A) adenosine receptor bound to the A(2A) receptor-specific antagonist, ZM241385, was recently determined at 2.6-A resolution. Surprisingly, the antagonist binds in an extended conformation, perpendicular to the plane of the membrane, and indicates a number of interactions unidentified before in ZM241385 recognition. To further understand the selectivity of ZM241385 for the human A(2A) adenosine receptor, we examined the effect of mutating amino acid residues within the binding cavity likely to have key interactions and that have not been previously examined. Mutation of Phe-168 to Ala abolishes both agonist and antagonist binding as well as receptor activity, whereas mutation of this residue to Trp or Tyr had only moderate effects. The Met-177 --> Ala mutation impeded antagonist but not agonist binding. Finally, the Leu-249 --> Ala mutant showed neither agonist nor antagonist binding affinity. From our results and previously published mutagenesis data, we conclude that conserved residues Phe-168(5.29), Glu-169(5.30), Asn-253(6.55), and Leu-249(6.51) play a central role in coordinating the bicyclic core present in both agonists and antagonists. By combining the analysis of the mutagenesis data with a comparison of the sequences of different adenosine receptor subtypes from different species, we predict that the interactions that determine subtype selectivity reside in the more divergent "upper" region of the binding cavity while the "lower" part of the binding cavity is conserved across adenosine receptor subtypes.
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Affiliation(s)
- Veli-Pekka Jaakola
- Department of Molecular Biology, Scripps Research Institute, La Jolla, California 92037, USA
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12
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Baraldi PG, Tabrizi MA, Fruttarolo F, Romagnoli R, Preti D. Recent improvements in the development of A(2B) adenosine receptor agonists. Purinergic Signal 2009; 5:3-19. [PMID: 19184536 PMCID: PMC2721777 DOI: 10.1007/s11302-009-9140-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 02/27/2008] [Indexed: 11/25/2022] Open
Abstract
Adenosine is known to exert most of its physiological functions by acting as local modulator at four receptor subtypes named A(1), A(2A), A(2B) and A(3) (ARs). Principally as a result of the difficulty in identifying potent and selective agonists, the A(2B) AR is the least extensively characterised of the adenosine receptors family. Despite these limitations, growing understanding of the physiological meaning of this target indicates promising therapeutic perspectives for specific ligands. As A(2B) AR signalling seems to be associated with pre/postconditioning cardioprotective and anti-inflammatory mechanisms, selective agonists may represent a new therapeutic group for patients suffering from coronary artery disease. Herein we present an overview of the recent advancements in identifying potent and selective A(2B) AR agonists reported in scientific and patent literature. These compounds can be classified into adenosine-like and nonadenosine ligands. Nucleoside-based agonists are the result of modifying adenosine by substitution at the N (6)-, C(2)-positions of the purine heterocycle and/or at the 5'-position of the ribose moiety or combinations of these substitutions. Compounds 1-deoxy-1-{6-[N'-(furan-2-carbonyl)-hydrazino]-9H-purin-9-yl}-N-ethyl-beta-D-ribofuranuronamide (19, hA(1) K (i) = 1050 nM, hA(2A) K (i) = 1550 nM, hA(2B) EC(50) = 82 nM, hA(3) K (i) > 5 muM) and its 2-chloro analogue 23 (hA(1) K (i) = 3500 nM, hA(2A) K (i) = 4950 nM, hA(2B) EC(50) = 210 nM, hA(3) K (i) > 5 muM) were confirmed to be potent and selective full agonists in a cyclic adenosine monophosphate (cAMP) functional assay in Chinese hamster ovary (CHO) cells expressing hA(2B) AR. Nonribose ligands are represented by conveniently substituted dicarbonitrilepyridines, among which 2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]pyridin-2-ylsulfanyl]acetamide (BAY-60-6583, hA(1), hA(2A), hA(3) EC(50) > 10 muM; hA(2B) EC(50) = 3 nM) is currently under preclinical-phase investigation for treating coronary artery disorders and atherosclerosis.
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Affiliation(s)
- Pier Giovanni Baraldi
- Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via fossato di Mortara 17-19, 44100, Ferrara, Italy,
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Abstract
The development of potent and selective agonists and antagonists of adenosine receptors (ARs) has been a target of medicinal chemistry research for several decades, and recently the US Food and Drug Administration has approved Lexiscan, an adenosine derivative substituted at the 2 position, for use as a pharmacologic stress agent in radionuclide myocardial perfusion imaging. Currently, some other adenosine A(2A) receptor (A(2A)AR) agonists and antagonists are undergoing preclinical testing and clinical trials. While agonists are potent antiinflammatory agents also showing hypotensive effects, antagonists are being developed for the treatment of Parkinson's disease.However, since there are still major problems in this field, including side effects, low brain penetration (for the targeting of CNS diseases), short half-life, or lack of in vivo effects, the design and development of new AR ligands is a hot research topic.This review presents an update on the medicinal chemistry of A(2A)AR agonists and antagonists, and stresses the strong need for more selective ligands at the human A(2A)AR subtype, in particular in the case of agonists.
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Affiliation(s)
- Gloria Cristalli
- Dipartimento di Scienze Chimiche, Università di Camerino, 62032 Camerino (MC), Italy.
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14
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Borowiak T, Dutkiewicz G, Sośnicki JG, Jagodziński TS, Hansen PE. Secondary thioamide group deformations in different surroundings: The case of intramolecular NH···N hydrogen bond – An X-ray study combined with theoretical calculations. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2008.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Baraldi PG, Tabrizi MA, Fruttarolo F, Romagnoli R, Preti D. Recent improvements in the development of A(2B) adenosine receptor agonists. Purinergic Signal 2008; 4:287-303. [PMID: 18443746 PMCID: PMC2583210 DOI: 10.1007/s11302-008-9097-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 02/27/2008] [Indexed: 10/31/2022] Open
Abstract
Adenosine is known to exert most of its physiological functions by acting as local modulator at four receptor subtypes named A(1), A(2A), A(2B) and A(3) (ARs). Principally as a result of the difficulty in identifying potent and selective agonists, the A(2B) AR is the least extensively characterised of the adenosine receptors family. Despite these limitations, growing understanding of the physiological meaning of this target indicates promising therapeutic perspectives for specific ligands. As A(2B) AR signalling seems to be associated with pre/postconditioning cardioprotective and anti-inflammatory mechanisms, selective agonists may represent a new therapeutic group for patients suffering from coronary artery disease. Herein we present an overview of the recent advancements in identifying potent and selective A(2B) AR agonists reported in scientific and patent literature. These compounds can be classified into adenosine-like and nonadenosine ligands. Nucleoside-based agonists are the result of modifying adenosine by substitution at the N (6)-, C(2)-positions of the purine heterocycle and/or at the 5'-position of the ribose moiety or combinations of these substitutions. Compounds 1-deoxy-1-{6-[N'-(furan-2-carbonyl)-hydrazino]-9H-purin-9-yl}-N-ethyl-beta-D-ribofuranuronamide (19, hA(1) K (i) = 1050 nM, hA(2A) K (i) = 1550 nM, hA(2B) EC(50) = 82 nM, hA(3) K (i) > 5 muM) and its 2-chloro analogue 23 (hA(1) K (i) = 3500 nM, hA(2A) K (i) = 4950 nM, hA(2B) EC(50) = 210 nM, hA(3) K (i) > 5 muM) were confirmed to be potent and selective full agonists in a cyclic adenosine monophosphate (cAMP) functional assay in Chinese hamster ovary (CHO) cells expressing hA(2B) AR. Nonribose ligands are represented by conveniently substituted dicarbonitrilepyridines, among which 2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]pyridin-2-ylsulfanyl]acetamide (BAY-60-6583, hA(1), hA(2A), hA(3) EC(50) > 10 muM; hA(2B) EC(50) = 3 nM) is currently under preclinical-phase investigation for treating coronary artery disorders and atherosclerosis.
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Affiliation(s)
- Pier Giovanni Baraldi
- Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via fossato di Mortara 17-19, 44100, Ferrara, Italy,
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16
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Cristalli G, Cacciari B, Dal Ben D, Lambertucci C, Moro S, Spalluto G, Volpini R. Highlights on the development of A(2A) adenosine receptor agonists and antagonists. ChemMedChem 2008; 2:260-81. [PMID: 17177231 DOI: 10.1002/cmdc.200600193] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although significant progress has been made in the past few decades demonstrating that adenosine modulates a variety of physiological and pathophysiological processes through the interaction with four subtypes of a family of cell-surface G-protein-coupled receptors, clinical evaluation of some adenosine receptor ligands has been discontinued. Major problems include side effects due to the wide distribution of adenosine receptors, low brain penetration (which is important for the targeting of CNS diseases), short half-life of compounds, or a lack of effects, in some cases perhaps due to receptor desensitization or to low receptor density in the targeted tissue. Currently, three A(2A) adenosine receptor agonists have begun phase III studies. Two of them are therapeutically evaluated as pharmacologic stress agents and the third proved to be effective in the treatment of acute spinal cord injury (SCI), while avoiding the adverse effects of steroid agents. On the other hand, the great interest in the field of A(2A) adenosine receptor antagonists is related to their application in neurodegenerative disorders, in particular, Parkinson's disease, and some of them are currently in various stages of evaluation. This review presents an update of medicinal chemistry and molecular recognition of A(2A) adenosine receptor agonists and antagonists, and stresses the strong need for more selective ligands at the A(2A) human subtype.
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Affiliation(s)
- Gloria Cristalli
- Dipartimento di Scienze Chimiche, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy.
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Ivanov AA, Palyulin VA, Zefirov NS. Computer aided comparative analysis of the binding modes of the adenosine receptor agonists for all known subtypes of adenosine receptors. J Mol Graph Model 2007; 25:740-54. [PMID: 17095272 DOI: 10.1016/j.jmgm.2006.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 06/20/2006] [Accepted: 06/21/2006] [Indexed: 12/01/2022]
Abstract
Molecular models of all known subtypes (A1, A2A, A2B, and A3) of the human adenosine receptors were built in homology with bovine rhodopsin. These models include the transmembrane domain as well as all extracellular and intracellular hydrophilic loops and terminal domains. The molecular docking of adenosine and 46 selected derivatives was performed for each receptor subtype. A binding mode common for all studied agonists was proposed, and possible explanations for differences in the ligand activities were suggested.
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Affiliation(s)
- Andrei A Ivanov
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119992 Moscow, Russian Federation
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18
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Triazoloquinazolines as Human A3 Adenosine Receptor Antagonists: A QSAR Study. Int J Mol Sci 2006. [DOI: 10.3390/i7110485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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19
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Cordeaux Y, IJzerman AP, Hill SJ. Coupling of the human A1 adenosine receptor to different heterotrimeric G proteins: evidence for agonist-specific G protein activation. Br J Pharmacol 2004; 143:705-14. [PMID: 15302686 PMCID: PMC1575922 DOI: 10.1038/sj.bjp.0705925] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The present study investigates the effect of varying ligand structure on the ability of agonists to activate guanine nucleotide-binding proteins of the Gi, Gs and Gq families via the A(1) adenosine receptor. In CHO cells expressing this receptor, inhibition or potentiation of forskolin-stimulated cAMP accumulation was used as an end point to measure the activation of Gi and, in Pertussis toxin (PTX)-treated cells, Gs, respectively. Stimulation of inositol phosphate accumulation in PTX-treated cells was used as an index of Gq activation. CPA (N(6)-cyclopentyladenosine), NECA (5'-N-ethyl-carboxyamidoadenosine) and eight analogues of these ligands presented a range of guanine nucleotide-binding protein (G-protein)-activating profiles. Some ligands could only activate Gi (e.g. 2'deoxyCPA), some primarily Gi and Gs (and only weakly Gq) (e.g. 3'deoxyCPA), highlighting the importance of the ribose hydroxyls in agonist activation of multiple G proteins. CHA (N(6)-cyclohexyladenosine) activated Gi, Gs and Gq, but was more efficacious than CPA in activating Gs. The NECA analogues 5'-N-cyclopropyl-carboxamidoadenosine, 5'-N-cyclobutyl-carboxamidoadenosine and 5'-N-cyclopentyl-carboxamidoadenosine (CPeCA) also activated all three G proteins, although their ability to activate Gs and Gq (relative to CPA) was reduced with increasing substituent size, such that CPeCA produced only a small stimulation (at 100 microM) at Gq, but was a full agonist, relative to CPA, at Gi and Gs. This study suggests that the A(1) adenosine receptor can adopt agonist-specific conformations, arising from small changes in ligand structure, which lead to the differential activation of Gi, Gs and Gq.
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Affiliation(s)
- Yolande Cordeaux
- Institute of Cell Signalling, Medical School, University of Nottingham, Nottingham NG7 2UH
| | - Adriaan P IJzerman
- Leiden/Amsterdam Centre for Drug research, Division of Medicinal Chemistry, Leiden, Netherlands
| | - Stephen J Hill
- Institute of Cell Signalling, Medical School, University of Nottingham, Nottingham NG7 2UH
- Author for correspondence:
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20
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Gutiérrez-de-Terán H, Pastor M, Centeno NB, Aqvist J, Sanz F. Comparative Analysis of Putative Agonist-Binding Modes in the Human A1 Adenosine Receptor. Chembiochem 2004; 5:841-9. [PMID: 15174168 DOI: 10.1002/cbic.200300817] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A recent study reported a model of the human A(1) adenosine receptor and its agonist binding site, proposing two putative binding modes in the same binding site for the natural agonist, adenosine. The present work investigates the flexibility of this binding site by exhaustive exploration with the natural agonist and with three other adenosine derivatives: N6-cyclopentyladenosine (CPA), 2-chloro-N6-cyclopentyladenosine (CCPA), and 5'-N-ethylcarboxamidoadenosine (NECA). Our aim was to find a common binding mode for agonists that would explain the role in the binding process of the different substitutions allowed at the 2, N6, and 5' positions of adenosine. This problem was addressed through docking simulations, molecular dynamics studies, and estimations of the ligand-binding free energy with both the AUTODOCK scoring function and the linear interaction energy (LIE) approach. The results point to a single receptor-binding position that explains the effects of the different chemical modifications on the adenosine derivatives considered here.
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Affiliation(s)
- Hugo Gutiérrez-de-Terán
- Research Group on Biomedical Informatics (GRIB), Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Carrer Dr. Aiguader 80, 08003 Barcelona, Spain
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21
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Beukers MW, van Oppenraaij J, van der Hoorn PPW, Blad CC, den Dulk H, Brouwer J, IJzerman AP. Random mutagenesis of the human adenosine A2B receptor followed by growth selection in yeast. Identification of constitutively active and gain of function mutations. Mol Pharmacol 2004; 65:702-10. [PMID: 14978249 DOI: 10.1124/mol.65.3.702] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To gain insight in spontaneous as well as agonist-induced activation of the human adenosine A2B receptor, we applied a random mutagenesis approach in yeast to create a large number of receptor mutants and selected mutants of interest with a robust screening assay based on growth. The amino acid sequence of 14 mutated receptors was determined. All these mutated receptors displayed constitutive activity. In particular, single-point mutations at T42A, V54L, and F84S and a triple-point mutation at N36S, T42A, and T66A resulted in high constitutive activity. In addition, a C-terminally truncated (after Lys269) mutant, Q214L I230N V240M V250M N254Y T257S K269stop, was highly constitutively active. The T42A, V54L, and F84S mutants showed a considerable decrease, 4.9- to 6.9-fold, in the EC50 value of 5'-N-ethylcarboxamidoadenosine (NECA), an adenosine analog. Combined mutation of I242T, K269R, V284A, and H302Q, as well as F84L together with S95G, resulted in an even greater potency of NECA of 10- and 18-fold, respectively. In fact, all constitutively active mutants had an increased potency for NECA. This suggests that the wild-type (wt) human A2B receptor itself is rather silent, which may explain the low affinity of agonists for this receptor. To verify the ability of the mutant receptors to activate mammalian second messenger systems, cAMP experiments were performed in CHO cells stably expressing the wt and T42A receptors. These experiments confirmed the increased sensitivity of T42A for NECA, because the EC50 values of T42A and the wt receptor were 0.15 +/- 0.04 and 1.3 +/- 0.4 microM, respectively.
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Affiliation(s)
- Margot W Beukers
- Division of Medicinal Chemistry, LACDR, Gorlaeus Laboratories, Leiden, The Netherlands.
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22
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van Muijlwijk-Koezen JE, Timmerman H, Ijzerman AP. The adenosine A3 receptor and its ligands. PROGRESS IN MEDICINAL CHEMISTRY 2002; 38:61-113. [PMID: 11774799 DOI: 10.1016/s0079-6468(08)70092-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Affiliation(s)
- J E van Muijlwijk-Koezen
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Department of Pharmacochemistry, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
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23
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van Tilburg EW, von Frijtag Drabbe Kunzel J, de Groote M, IJzerman AP. 2,5'-Disubstituted adenosine derivatives: evaluation of selectivity and efficacy for the adenosine A(1), A(2A), and A(3) receptor. J Med Chem 2002; 45:420-9. [PMID: 11784146 DOI: 10.1021/jm010952v] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Novel 2,5'-disubstituted adenosine derivatives were synthesized in good overall yields starting from commercially available guanosine. Binding affinities were determined for rat adenosine A(1) and A(2A) receptors and human A(3) receptors. E(max) values were determined for the stimulation or inhibition of cAMP production in CHO cells expressing human adenosine A(2A) (EC(50) values as well) or A(3) receptors, respectively. The compounds displayed affinities in the nanomolar range for both the adenosine A(2A) and A(3) receptor, without substantial preference for either receptor. The derivatives with a 2-(1-hexynyl) group had the highest affinities for both receptors; compound 4 (2-(1-hexynyl)adenosine) had the highest affinity for the adenosine A(2A) receptor with a K(i) value of 6 nM (A(3)/A(2A) selectivity ratio of approximately 3), whereas compound 37 (2-(1-hexynyl)-5'-S-methyl-5'-thioadenosine) had the highest affinity for the adenosine A(3) receptor with a K(i) value of 15 nM (A(2A)/A(3) selectivity ratio of 4). In general, compounds with a relatively small 5'-S-alkyl-5'-thio substituent (methyl-5'-thio) displayed the highest affinities for both the adenosine A(2A) and A(3) receptor; the larger ones (n- or i-propyl-5'-thio) increased the selectivity for the adenosine A(3) receptor. The novel compounds were also evaluated in cAMP assays for their (partial) agonistic behavior. Overall, the disubstituted derivatives behaved as partial agonists for both the adenosine A(2A) and A(3) receptor. The compounds showed somewhat higher intrinsic activities on the adenosine A(2A) receptor than on the A(3) receptor. Compounds 37, 40 and 45, 48, with either a 5'-S-methyl-5'-thio or a 5'-S-i-propyl-5'-thio substituent had the lowest intrinsic activities on the adenosine A(2A) receptor. For the A(3) receptor, compounds 34, 35, 38, 39, and 46, 47, with a 5'-S-ethyl-5'-thio or a 5'-S-n-propyl-5'-thio substituent had the lowest intrinsic activities.
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Affiliation(s)
- Erica W van Tilburg
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
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24
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Da Settimo F, Primofiore G, Taliani S, Marini AM, La Motta C, Novellino E, Greco G, Lavecchia A, Trincavelli L, Martini C. 3-Aryl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-ones: a new class of selective A1 adenosine receptor antagonists. J Med Chem 2001; 44:316-27. [PMID: 11462973 DOI: 10.1021/jm001054m] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Radioligand binding assays using bovine cortical membrane preparations and biochemical in vitro studies revealed that various 3-aryl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-one (ATBI) derivatives, previously reported by us as ligands of the central benzodiazepine receptor (BzR) (Primofiore, G.; et al. J. Med. Chem. 2000, 43, 96-102), behaved as antagonists at the A1 adenosine receptor (A1AR). Alkylation of the nitrogen at position 10 of the triazinobenzimidazole nucleus conferred selectivity for the A1AR vs the BzR. The most potent ligand of the ATBI series (10-methyl-3-phenyl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-one 12) displayed a Ki value of 63 nM at the A1AR without binding appreciably to the adenosine A2A and A3 nor to the benzodiazepine receptor. Pharmacophore-based modeling studies in which 12 was compared against a set of well-established A1AR antagonists suggested that three hydrogen bonding sites (HB1 acceptor, HB2 and HB3 donors) and three lipophilic pockets (L1, L2, and L3) might be available to antagonists within the A1AR binding cleft. According to the proposed pharmacophore scheme, the lead compound 12 engages interactions with the HB2 site (via the N2 nitrogen) as well as with the L2 and L3 sites (through the pendant and the fused benzene rings). The results of these studies prompted the replacement of the methyl with more lipophilic groups at the 10-position (to fill the putative L1 lipophilic pocket) as a strategy to improve A1AR affinity. Among the new compounds synthesized and tested, the 3,10-diphenyl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-one (23) was characterized by a Ki value of 18 nM which represents a 3.5-fold gain of A1AR affinity compared with the lead 12. A rhodopsin-based model of the bovine adenosine A1AR was built to highlight the binding mode of 23 and two well-known A1AR antagonists (III and VII) and to guide future lead optimization projects. In our docking simulations, 23 receives a hydrogen bond (via the N1 nitrogen) from the side chain of Asn247 (corresponding to the HB1 and HB2 sites) and fills the L1, L2, and L3 lipophilic pockets with the 10-phenyl, 3-phenyl, and fused benzene rings, respectively.
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Affiliation(s)
- F Da Settimo
- Dipartimento di Scienze Farmaceutiche, Università di Pisa, Italy.
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25
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Umino T, Yoshioka K, Saitoh Y, Minakawa N, Nakata H, Matsuda A. Nucleosides and nucleotides. 200. Reinvestigation of 5'-N-ethylcarboxamidoadenosine derivatives: structure-activity relationships for P(3) purinoceptor-like proteins. J Med Chem 2001; 44:208-14. [PMID: 11170630 DOI: 10.1021/jm000150k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The non-P(1) and non-P(2) muscle relaxant effect of ATP in rabbit thoracic aorta has recently been attributed to a putative P(3) purinoceptor, which is activated by either adenosine or ATP. Since the physiological roles of this putative P(3) purinoceptor and of a new [(3)H]-5'-N-ethylcarboxamidoadenosine (NECA)-binding protein from rat brain membranes called P(3) purinoceptor-like protein (P(3)LP), due to its ligand specificity, have not been fully elucidated, we needed a specific ligand to obtain further information about the receptor. We examined the structure-activity relationship (SAR) of various 5'-N-substituted-carboxamidoadenosine derivatives toward P(3)LP and discovered a hydrophobic binding region near the 5'-N-substituted-carboxamide group. From the linear alkyl N-substituted derivatives, the N-n-pentyl derivative 10 was found to be the most potent ligand with a K(i) value of 12 nM. In the series of the N-cycloalkyl derivatives, the N-cyclohexyl derivative 27 was the strongest ligand with a K(i) value of 18 nM. On the other hand, the N-substituents having branched alkyl side chains and bulky cycloalkyl groups did not show any potent affinities for P(3)LP. Therefore, the hydrophobic pocket accommodates approximately a 10-carbon-atom-long linear alkyl side chain, while a considerably stronger hydrophobic binding region of about a 5-carbon-atom-long depth exists near the nitrogen atom of the amide group. This pocket also allows substitution with bulky hydrophobic groups since the 5'-N-cycloalkyl derivatives have high affinities. We also examined the receptor selectivity for the selected nucleosides 10 and 27 with 1 [9-(6,7-dideoxy-beta-D-allo-hept-5-ynofuranosyl)adenine, HAK2701] and NECA versus P(1) purinoceptor subtypes, such as adenosine A(1), A(2A), A(2B), and A(3) receptors, and found that 27 is the most selective ligand for P(3)LP.
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Affiliation(s)
- T Umino
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
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26
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Beukers MW, den Dulk H, van Tilburg EW, Brouwer J, Ijzerman AP. Why are A(2B) receptors low-affinity adenosine receptors? Mutation of Asn273 to Tyr increases affinity of human A(2B) receptor for 2-(1-Hexynyl)adenosine. Mol Pharmacol 2000; 58:1349-56. [PMID: 11093773 DOI: 10.1124/mol.58.6.1349] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenosine A(2B) receptors are known as low-affinity receptors due to their modest-to-negligible affinity for adenosine and prototypic agonists. Despite numerous synthetic efforts, 5'-N-ethylcarboxamidoadenosine (NECA) still is the reference agonist, albeit nonselective for this receptor. In our search for higher affinity agonists, we developed decision schemes to select amino acids for mutation to the corresponding residues in the most homologous, higher affinity, human A(2A) receptor. One scheme exploited knowledge on sequence alignments and modeling data and yielded three residues, V11, L58, and F59, mutation of which did not affect agonist affinity. The second scheme combined knowledge on sequence alignments and mutation data and pointed to Ala12 and Asn273. Mutation of Ala12 to threonine did not affect the affinity for NECA, (R)-N(6)-(phenylisopropyl)adenosine (R-PIA), and 2Cl Ado. The affinity of the N273Y mutant for NECA and R-PIA and for the antagonists xanthine amine congener (XAC), ZM241385, and SCH58261 was also unaltered. However, this mutant had a slightly increased affinity for a 2-substituted adenosine derivative, CGS21680. This prompted us to investigate other 2-substituted adenosines, with selectivity and high affinity for A(2A) receptors. All four compounds tested had improved affinity for the N273Y receptor. Of these, 2-(1-hexynyl)adenosine had submicromolar affinity for the N273Y receptor, 0.18 +/- 0.10 microM, with a 61-fold affinity gain over the wt receptor. In addition, the non-NECA analog (S)-PHP adenosine had an affinity of 1.7 +/- 0.5 microM for the wt receptor. The high affinity of (S)-PHP adenosine for the wt receptor suggests that further modifications at the 2-position may yield agonists with even higher affinity for A(2B) receptors.
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Affiliation(s)
- M W Beukers
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
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27
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Sak K, Uri A, Enkvist E, Raidaru G, Subbi J, Kelve M, Järv J. Adenosine-derived non-phosphate antagonists for P2Y(1) purinoceptors. Biochem Biophys Res Commun 2000; 272:327-31. [PMID: 10833413 DOI: 10.1006/bbrc.2000.2775] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Novel type antagonists for P2Y(1) adenine nucleotide receptors were synthesized by coupling of adenosine 5'-OH group with oligo-aspartate chain via a carbonyl linker. All these conjugates (AdoOC(O)Asp(n), n = 1-4) inhibited the 2MeSADP-stimulated synthesis of inositol phosphates in 1321N1 human astrocytoma cells stably expressing human P2Y(1) receptors. This inhibitory effect followed the rank order AdoOC(O)Asp(2)> AdoOC(O)Asp(3)> AdoOC(O)Asp(1)> AdoOC(O)Asp(4) with antagonistic constant pA(2) = 5.4 for AdoOC(O)Asp(2). Potency of this non-phosphate inhibitor was comparable with the previously known adenosine 3',5'- and 2', 5'-bisphosphates. Chemical and biological stabilities of these novel adenosine derived antagonists of the nucleotide receptor provide perspectives of their pharmacological implication.
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Affiliation(s)
- K Sak
- Institute of Chemical Physics, University of Tartu, Estonia
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28
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Baraldi PG, Cacciari B, Romagnoli R, Merighi S, Varani K, Borea PA, Spalluto G. A(3) adenosine receptor ligands: history and perspectives. Med Res Rev 2000; 20:103-28. [PMID: 10723024 DOI: 10.1002/(sici)1098-1128(200003)20:2<103::aid-med1>3.0.co;2-x] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Adenosine regulates many physiological functions through specific cell membrane receptors. On the basis of pharmacological studies and molecular cloning, four different adenosine receptors have been identified and classified as A(1), A(2A), A(2B), and A(3). These adenosine receptors are members of the G-protein-coupled receptor family. While adenosine A(1) and A(2A) receptor subtypes have been pharmacologically characterized through the use of selective ligands, the A(3) adenosine receptor subtype is presently under study in order to better understand its physio-pathological functions. Activation of adenosine A(3) receptors has been shown to stimulate phospholipase C and D and to inhibit adenylate cyclase. Activation of A(3) adenosine receptors also causes the release of inflammatory mediators such as histamine from mast cells. These mediators are responsible for processes such as inflammation and hypotension. It has also been suggested that the A(3) receptor plays an important role in brain ischemia, immunosuppression, and bronchospasm in several animal models. Based on these results, highly selective A(3) adenosine receptor agonists and/or antagonists have been indicated as potential drugs for the treatment of asthma and inflammation, while highly selective agonists have been shown to possess cardioprotective effects. The updated material related to this field of research has been rationalized and arranged in order to offer an overview of the topic.
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Affiliation(s)
- P G Baraldi
- Dipartimento di Scienze Farmaceutiche, Universitá di Ferrara, Via Fossato di Mortara 17-19, I-44100 Ferrara, Italy.
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29
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de Zwart M, de Groote M, van der Klein PA, van Dun S, Bronsing R, von Frijtag Drabbe K�nzel JK, Ijzerman AP. Phenyl-substituted N6-phenyladenosines and N6-phenyl-5?-N-ethylcarboxamidoadenosines with high activity at human adenosine A2B receptors. Drug Dev Res 2000. [DOI: 10.1002/(sici)1098-2299(200002)49:2<85::aid-ddr2>3.0.co;2-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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