1
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Lee YS. Peptidomimetics and Their Applications for Opioid Peptide Drug Discovery. Biomolecules 2022; 12:biom12091241. [PMID: 36139079 PMCID: PMC9496382 DOI: 10.3390/biom12091241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Despite various advantages, opioid peptides have been limited in their therapeutic uses due to the main drawbacks in metabolic stability, blood-brain barrier permeability, and bioavailability. Therefore, extensive studies have focused on overcoming the problems and optimizing the therapeutic potential. Currently, numerous peptide-based drugs are being marketed thanks to new synthetic strategies for optimizing metabolism and alternative routes of administration. This tutorial review briefly introduces the history and role of natural opioid peptides and highlights the key findings on their structure-activity relationships for the opioid receptors. It discusses details on opioid peptidomimetics applied to develop therapeutic candidates for the treatment of pain from the pharmacological and structural points of view. The main focus is the current status of various mimetic tools and the successful applications summarized in tables and figures.
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Affiliation(s)
- Yeon Sun Lee
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
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2
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Claff T, Yu J, Blais V, Patel N, Martin C, Wu L, Han GW, Holleran BJ, Van der Poorten O, White KL, Hanson MA, Sarret P, Gendron L, Cherezov V, Katritch V, Ballet S, Liu ZJ, Müller CE, Stevens RC. Elucidating the active δ-opioid receptor crystal structure with peptide and small-molecule agonists. SCIENCE ADVANCES 2019; 5:eaax9115. [PMID: 31807708 PMCID: PMC6881160 DOI: 10.1126/sciadv.aax9115] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 09/25/2019] [Indexed: 05/13/2023]
Abstract
Selective activation of the δ-opioid receptor (DOP) has great potential for the treatment of chronic pain, benefitting from ancillary anxiolytic and antidepressant-like effects. Moreover, DOP agonists show reduced adverse effects as compared to μ-opioid receptor (MOP) agonists that are in the spotlight of the current "opioid crisis." Here, we report the first crystal structures of the DOP in an activated state, in complex with two relevant and structurally diverse agonists: the potent opioid agonist peptide KGCHM07 and the small-molecule agonist DPI-287 at 2.8 and 3.3 Å resolution, respectively. Our study identifies key determinants for agonist recognition, receptor activation, and DOP selectivity, revealing crucial differences between both agonist scaffolds. Our findings provide the first investigation into atomic-scale agonist binding at the DOP, supported by site-directed mutagenesis and pharmacological characterization. These structures will underpin the future structure-based development of DOP agonists for an improved pain treatment with fewer adverse effects.
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Affiliation(s)
- Tobias Claff
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Rd, Pudong, Shanghai 201210, China
- PharmaCenter Bonn, University of Bonn, Pharmaceutical Chemistry I, An der Immenburg 4, D-53121 Bonn, Germany
| | - Jing Yu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Rd, Pudong, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Véronique Blais
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Quebec J1H 5N4, Canada
| | - Nilkanth Patel
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Charlotte Martin
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Lijie Wu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Rd, Pudong, Shanghai 201210, China
| | - Gye Won Han
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Brian J. Holleran
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Quebec J1H 5N4, Canada
| | - Olivier Van der Poorten
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Kate L. White
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | | | - Philippe Sarret
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Quebec J1H 5N4, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Quebec J1H 5N4, Canada
| | - Vadim Cherezov
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Vsevolod Katritch
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Steven Ballet
- Research Group of Organic Chemistry, Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Zhi-Jie Liu
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Rd, Pudong, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Christa E. Müller
- PharmaCenter Bonn, University of Bonn, Pharmaceutical Chemistry I, An der Immenburg 4, D-53121 Bonn, Germany
- Corresponding author. (C.E.M.); (R.C.S.)
| | - Raymond C. Stevens
- iHuman Institute, ShanghaiTech University, Ren Building, 393 Middle Huaxia Rd, Pudong, Shanghai 201210, China
- Departments of Biological Sciences and Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
- Corresponding author. (C.E.M.); (R.C.S.)
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3
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Tryptophan-Containing Non-Cationizable Opioid Peptides - a new chemotype with unusual structure and in vivo activity. Future Med Chem 2017; 9:2099-2115. [PMID: 29130348 DOI: 10.4155/fmc-2017-0104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Recently, a new family of opioid peptides containing tryptophan came to the spotlight for the absence of the fundamental protonable tyramine 'message' pharmacophore. Structure-activity relationship investigations led to diverse compounds, characterized by different selectivity profiles and agonist or antagonist effects. Substitution at the indole of Trp clearly impacted peripheral/central antinociceptivity. These peculiarities prompted to gather all the compounds in a new class, and to coin the definition 'Tryptophan-Containing Non-Cationizable Opioid Peptides', in short 'TryCoNCOPs'. Molecular docking analysis suggested that the TryCoNCOPs can still interact with the receptors in an agonist-like fashion. However, most TryCoNCOPs showed significant differences between the in vitro and in vivo activities, suggesting that opioid activity may be elicited also via alternative mechanisms.
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4
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Remesic M, Lee YS, Hruby VJ. Cyclic Opioid Peptides. Curr Med Chem 2016; 23:1288-303. [PMID: 27117332 PMCID: PMC5693220 DOI: 10.2174/0929867323666160427123005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/26/2016] [Accepted: 03/18/2016] [Indexed: 11/22/2022]
Abstract
For decades the opioid receptors have been an attractive therapeutic target for the treatment of pain. Since the first discovery of enkephalin, approximately a dozen endogenous opioid peptides have been known to produce opioid activity and analgesia, but their therapeutics have been limited mainly due to low blood brain barrier penetration and poor resistance to proteolytic degradation. One versatile approach to overcome these drawbacks is the cyclization of linear peptides to cyclic peptides with constrained topographical structure. Compared to their linear parents, cyclic analogs exhibit better metabolic stability, lower offtarget toxicity, and improved bioavailability. Extensive structure-activity relationship studies have uncovered promising compounds for the treatment of pain as well as further elucidate structural elements required for selective opioid receptor activity. The benefits that come with employing cyclization can be further enhanced through the generation of polycyclic derivatives. Opioid ligands generally have a short peptide chain and thus the realm of polycyclic peptides has yet to be explored. In this review, a brief history of designing ligands for the opioid receptors, including classic linear and cyclic ligands, is discussed along with recent approaches and successes of cyclic peptide ligands for the receptors. Various scaffolds and approaches to improve bioavailability are elaborated and concluded with a discourse towards polycyclic peptides.
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Affiliation(s)
| | - Yeon Sun Lee
- Department of Chemistry and Biochemistry, 1306 E. University, P.O. Box 210041, University of Arizona, Tucson, Arizona 85721, USA.
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5
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Synthesis and biological evaluations of novel endomorphin analogues containing α-hydroxy-β-phenylalanine (AHPBA) displaying mixed μ/δ opioid receptor agonist and δ opioid receptor antagonist activities. Eur J Med Chem 2015; 92:270-81. [DOI: 10.1016/j.ejmech.2014.12.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 12/28/2014] [Indexed: 12/29/2022]
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6
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De Marco R, Tolomelli A, Spampinato S, Bedini A, Gentilucci L. Opioid activity profiles of oversimplified peptides lacking in the protonable N-terminus. J Med Chem 2012; 55:10292-6. [PMID: 22995061 DOI: 10.1021/jm301213s] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, we described cyclopeptide opioid agonists containing the d-Trp-Phe sequence. To expand the scope of this atypical pharmacophore, we tested the activity profiles of the linear peptides Ac-Xaa-Phe-Yaa (Xaa = l/d-Trp, d-His/Lys/Arg; Yaa = H, GlyNH(2)). Ac-d-Trp-PheNH(2) appeared to be the minimal binding sequence, while Ac-d-Trp-Phe-GlyNH(2) emerged as the first noncationizable short peptide (partial) agonist with high μ-opioid receptor affinity and selectivity. Conformational analysis suggested that 5 adopts in solution a β-turn conformation.
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Affiliation(s)
- Rossella De Marco
- Department of Chemistry "G. Ciamician", University of Bologna, Via Selmi 2, 40126 Bologna, Italy
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7
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Abstract
Developing short peptides into useful probes and therapeutic leads remains a difficult challenge. Structural rigidification is a proven method for improving the properties of short peptides. In this work, we report a strategy for stabilizing peptide macrocycles by introducing side-chain-to-side-chain staples to produce peptide bicycles with higher affinity, selectivity, and resistance to degradation. We have applied this strategy to G1, an 11-residue peptide macrocycle that binds the Src homology 2 (SH2) domain of growth-factor-bound protein 2 (Grb2). Several homodetic peptide bicycles were synthesized entirely on-resin with high yields. Two rounds of iterative design produced peptide bicycle BC1, which is 60 times more potent than G1 and 200 times more selective. Moreover, BC1 is completely intact after 24 hours in buffered human serum, conditions under which G1 is completely degraded. Our peptide-bicycle approach holds promise for the development of selective inhibitors of SH2 domains and other phosophotyrosine (pTyr)-binding proteins, as well as inhibitors of many other protein-protein interactions.
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Affiliation(s)
- Justin S. Quartararo
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Pianpian Wu
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Joshua A. Kritzer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
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8
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9
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Weltrowska G, Chung NN, Lemieux C, Guo J, Lu Y, Wilkes BC, Schiller PW. "Carba"-analogues of fentanyl are opioid receptor agonists. J Med Chem 2010; 53:2875-81. [PMID: 20218625 DOI: 10.1021/jm9019068] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There is evidence to indicate that the Asp residue in the third transmembrane helix (TMH) of opioid receptors forms a salt bridge with the positively charged nitrogen of endogenous and exogenous opioid ligands. To further examine the role of this electrostatic interaction in receptor binding and activation, we synthesized "carba"-analogues of a published fentanyl analogue containing a 3-(guanidinomethyl)-benzyl group in place of the phenyl moiety attached to the ethylamido group (C. Dardonville et al., Bioorg. Med. Chem. 2006, 14, 6570-6580 (1)), in which the piperidine ring nitrogen was replaced with a carbon. As expected, the resulting cis and trans isomers (8a and 8b) showed reduced mu and kappa opioid receptor binding affinities as compared to 1 but, surprisingly, retained opioid full agonist activity with about half the potency of leucine-enkephalin in the guinea pig ileum assay. In conjunction with performed receptor docking studies, these results indicate that the electrostatic interaction of the protonated nitrogen in the piperidine ring of fentanyl analogues with the Asp residue in the third TMH is not a conditio sine qua non for opioid receptor activation.
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Affiliation(s)
- Grazyna Weltrowska
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec, Canada H2W 1R7
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10
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Nascent structure–activity relationship study of a diastereomeric series of kappa opioid receptor antagonists derived from CJ-15,208. Bioorg Med Chem Lett 2009; 19:3647-50. [DOI: 10.1016/j.bmcl.2009.04.105] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 04/21/2009] [Accepted: 04/22/2009] [Indexed: 01/17/2023]
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11
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Gentilucci L, Squassabia F, Demarco R, Artali R, Cardillo G, Tolomelli A, Spampinato S, Bedini A. Investigation of the interaction between the atypical agonist c[YpwFG] and MOR. FEBS J 2008; 275:2315-37. [DOI: 10.1111/j.1742-4658.2008.06386.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Dolle RE, Michaut M, Martinez-Teipel B, Belanger S, Graczyk TM, DeHaven RN. Further studies of tyrosine surrogates in opioid receptor peptide ligands. Bioorg Med Chem Lett 2007; 17:2656-60. [PMID: 17350835 DOI: 10.1016/j.bmcl.2007.01.092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 01/29/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
A series of opioid peptide ligands containing modified N-terminal tyrosine (Tyr) residues was prepared and evaluated against cloned human mu, delta, and kappa opioid receptors. This work extends the recent discovery that (S)-4-carboxamidophenylalanine (Cpa) is an effective tyrosine bioisostere. Amino acids containing negatively charged functional groups in place of tyrosine's phenolic hydroxyl lacked receptor affinity, while exchange of Tyr for (S)-4-aminophenylalanine was modestly successful. Peptides containing the new amino acids, (S)-4-carboxamido-2,6-dimethylphenylalanine (Cdp) and (S)-beta-(2-aminobenzo[d]thiazol-6-yl)alanine (Aba), displayed binding (K(i)) and functional (EC(50)) profiles comparable to the parent ligands at the three receptors. Cdp represents the best performing Tyr surrogate in terms of overall activity, while Cpa and Aba show a subtle proclivity toward the delta receptor.
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MESH Headings
- Chemistry, Pharmaceutical/methods
- Cloning, Molecular
- Drug Design
- Humans
- Hydrogen Bonding
- Kinetics
- Ligands
- Models, Chemical
- Molecular Conformation
- Peptides/chemistry
- Receptors, Opioid/chemistry
- Receptors, Opioid, delta/chemistry
- Receptors, Opioid, kappa/chemistry
- Receptors, Opioid, mu/chemistry
- Tyrosine/chemistry
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Affiliation(s)
- Roland E Dolle
- Department of Chemistry, Adolor Corporation, 700 Pennsylvania Drive, Exton, PA 19341, USA.
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13
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Zhang Q, Keenan SM, Peng Y, Nair AC, Yu SJ, Howells RD, Welsh WJ. Discovery of novel triazole-based opioid receptor antagonists. J Med Chem 2006; 49:4044-7. [PMID: 16821764 PMCID: PMC2693423 DOI: 10.1021/jm0601250] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We report the computer-aided design, chemical synthesis, and biological evaluation of a novel family of delta opioid receptor (DOR) antagonists containing a 1,2,4-triazole core structure that are structurally distinct from other known opioid receptor active ligands. Among those delta antagonists sharing this core structure, 8 exhibited strong binding affinity (K(i) = 50 nM) for the DOR and appreciable selectivity for delta over mu and kappa opioid receptors (delta/mu = 80; delta/kappa > 200).
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Affiliation(s)
| | | | | | | | | | | | - William J. Welsh
- To whom correspondence should be addressed. Phone: 732−235−3234. Fax: 732−235−3475. E-mail:
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14
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Lu Y, Lum TK, Leow Augustine YW, Weltrowska G, Nguyen TMD, Lemieux C, Chung NN, Schiller PW. Replacement of the N-terminal Tyrosine Residue in Opioid Peptides with 3-(2,6-Dimethyl-4-carbamoylphenyl)propanoic Acid (Dcp) Results in Novel Opioid Antagonists. J Med Chem 2006; 49:5382-5. [PMID: 16913729 DOI: 10.1021/jm060369k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
3-(2,6-Dimethyl-4-carbamoylphenyl)propanoic acid (Dcp), a 2',6'-dimethyltyrosine analogue containing a carbamoyl group in place of the hydroxyl function and lacking the amino group, was synthesized. The replacement of Tyr1 in an enkephalin analogue and in dynorphin A(1-11)-NH2 with Dcp resulted in the first opioid peptide-derived antagonists that do not contain a phenolic hydroxyl group at the 1-position residue. The cyclic peptide Dcp-c[D-Cys-Gly-Phe(pNO2)-D-Cys]NH2 represents a novel, potent mu opioid antagonist.
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Affiliation(s)
- Yixin Lu
- Department of Chemistry and Medicinal Chemistry Program, Office of Life Sciences, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
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15
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Weltrowska G, Lu Y, Lemieux C, Chung NN, Schiller PW. A novel cyclic enkephalin analogue with potent opioid antagonist activity. Bioorg Med Chem Lett 2005; 14:4731-3. [PMID: 15324897 DOI: 10.1016/j.bmcl.2004.06.077] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Accepted: 06/23/2004] [Indexed: 11/27/2022]
Abstract
2',6'-Dimethyl substitution of the Tyr(1) residue in opioid agonist peptides and deletion of the N-terminal amino group, as achieved by replacement of Tyr(1) with 3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid (Dhp), have been shown to produce opioid antagonists. To examine the effect of beta-methylation of Dhp(1) in opioid peptides on the activity profile, stereoselective syntheses of (3S)- and (3R)-3-methyl-3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid [(3S)- and (3R)-Mdp] were carried out. In comparison with the cyclic parent antagonist peptide Dhp-c[D-Cys-Gly-Phe(pNO(2))-D-Cys]NH(2), the methylated analogue (3S)-Mdp-c[D-Cys-Gly-Phe(pNO(2))-D-Cys]NH(2) showed higher micro, delta and kappa antagonist potencies in functional assays and higher binding affinities for micro, delta and kappa opioid receptors (K(i)(micro)=2.03 nM; K(i)(delta)=2.34 nM; K(i)(kappa)=49.5 nM), whereas the corresponding (3R)-Mdp(1)-analogue was less potent by 1-2 orders of magnitude.
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MESH Headings
- Animals
- Enkephalins/chemical synthesis
- Enkephalins/chemistry
- Enkephalins/pharmacology
- In Vitro Techniques
- Male
- Methylation
- Mice
- Narcotic Antagonists/chemical synthesis
- Narcotic Antagonists/chemistry
- Narcotic Antagonists/pharmacology
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
- Structure-Activity Relationship
- Vas Deferens/drug effects
- Vas Deferens/metabolism
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Affiliation(s)
- Grazyna Weltrowska
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec, Canada H2W 1R7
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16
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Li T, Fujita Y, Tsuda Y, Miyazaki A, Ambo A, Sasaki Y, Jinsmaa Y, Bryant SD, Lazarus LH, Okada Y. Development of Potent μ-Opioid Receptor Ligands Using Unique Tyrosine Analogues of Endomorphin-2. J Med Chem 2005; 48:586-92. [PMID: 15658871 DOI: 10.1021/jm049384k] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Six analogues of tyrosine, which contained alkyl groups at positions 2', 3', and 6', either singly or in combination on the tyramine ring, were investigated for their effect on the opioid activity of [Xaa(1)]endomorphin-2 (EM-2). The opioid analogues displayed the following characteristics: (i) high mu-opioid receptor affinity [K(i)(mu) = 0.063-2.29 nM] with selectivity [K(i)(delta)/K(i)(mu)] ranging from 46 to 5347; (ii) potent functional mu-opioid agonism [GPI assay (IC(50) = 0.623-0.924 nM)] and with a correlation between delta-opioid receptor affinities and functional bioactivity using MVD; (iii) intracerebroventricular administration of [Dmt(1)]- (14) and [Det(1)]EM-2 (10) produced a dose-response antinociception in mice, with the former analogue more active than the latter; and (iv) a marked shift occurred from the trans-orientation at the Tyr(1)-Pro(2) bond to a cis-conformer compared to that observed previously with [Dmt(1)]EM-2 (14) (Okada et al. Bioorg. Med. Chem. 2003, 11, 1983-1984) except [Mmt(1)]EM-2 (7). The active profile of the [Xaa(1)]EM-2 analogues indicated that significant modifications on the tyramine ring are possible while high biological activity is maintained.
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MESH Headings
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/pharmacology
- Animals
- Binding, Competitive
- Brain/metabolism
- Guinea Pigs
- Ileum/drug effects
- Ileum/innervation
- Ileum/physiology
- In Vitro Techniques
- Ligands
- Male
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/innervation
- Muscle, Smooth/physiology
- Oligopeptides/chemical synthesis
- Oligopeptides/chemistry
- Oligopeptides/pharmacology
- Radioligand Assay
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, mu/agonists
- Stereoisomerism
- Structure-Activity Relationship
- Tyrosine/analogs & derivatives
- Tyrosine/chemical synthesis
- Tyrosine/chemistry
- Tyrosine/pharmacology
- Vas Deferens/drug effects
- Vas Deferens/physiology
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Affiliation(s)
- Tingyou Li
- The Graduate School of Food and Medicinal Sciences, Faculty of Pharmaceutical Sciences, and High Technology Research Center, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan
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17
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Cardillo G, Gentilucci L, Tolomelli A, Spinosa R, Calienni M, Qasem AR, Spampinato S. Synthesis and evaluation of the affinity toward mu-opioid receptors of atypical, lipophilic ligands based on the sequence c[-Tyr-Pro-Trp-Phe-Gly-]. J Med Chem 2004; 47:5198-203. [PMID: 15456262 DOI: 10.1021/jm0498811] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An ultimate and general model describing the interaction between opioid ligands and mu-opioid receptors is not available yet, so the mode of action of atypical peptide analogues or peptidomimetics is worthy of investigation. In this context, the peptide c[-Tyr-d-Pro-d-Trp-Phe-Gly-] was observed to act as an agonist toward mu-opioid receptors with appreciable potency, albeit deprived of a protonable nitrogen. This compound was synthesized as a member of a library of diastereo- or enantiomeric cyclic peptides based on the sequence of endomorphin-1, aiming to obtain lipophilic peptide ligands active at the mu-opioid receptors, having good performances in terms of resistance to enzymatic degradation and permeation of biological barriers.
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Affiliation(s)
- Giuliana Cardillo
- Dipartimento di Chimica G. Ciamician and CSFM, via Selmi 2, Università di Bologna, 40126 Bologna, Italy.
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18
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Kocsis L, Orosz G, Magyar A, Al-Khrasani M, Kató E, Rónai AZ, Bes B, Meunier JC, Gündüz O, Tóth G, Borsodi A, Benyhe S. Nociceptin antagonism: probing the receptor by N-acetyl oligopeptides. ACTA ACUST UNITED AC 2004; 122:199-207. [PMID: 15491792 DOI: 10.1016/j.regpep.2004.06.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Revised: 06/07/2004] [Accepted: 06/17/2004] [Indexed: 11/26/2022]
Abstract
In search for effective antagonist structures for the nociceptin (NOP) receptor, a number of N-acylated oligopeptides, including N-acyl tetra- and pentapeptides selective for the kappa-opioid receptor, as well as N-acyl hexapeptides bearing the Ac-Arg-Tyr-Tyr-Arg-Ile-Lys (Ac-RYYRIK) core sequence originally isolated from combinatorial chemical libraries, were synthesized and studied in radioreceptor binding assays, [(35)S]GTPgammaS functional tests and in mouse vas deferens (MVD) bioassays. The properties of the novel antagonist candidates were compared to known antagonists. A new antagonist structure with a reduced, primer alcohol C-terminus, Ac-Arg-Tyr-Tyr-Arg-Ile-lysinol (Ac-RYYRIK-ol) was described in the mouse vas deferens tests, showing an equilibrium inhibitory constant value (K(e)) of 2.44 nM, and no agonist effect at 10 microM ligand concentration. Schild-analysis indicated a clearly competitive interaction at the NOP receptor, whereas the peptide did not affect the action of the delta-opioid receptor agonist [D-Ala(2),D-Leu(5)]enkephalin. Ac-RYYRIK-ol also exhibited a high affinity in [(3)H]nociceptin-NH(2) binding competition assays using rat brain membranes. Agonist-induced G-protein activation via NOP receptors was studied in [(35)S]GTPgammaS binding stimulation assays by the use of both native brain tissue preparations and membranes from cultured CHO cells expressing recombinant nociceptin receptors. Ac-RYYRIK-ol displayed only weak intrinsic agonist activity, whereas it effectively inhibited the stimulation generated by nociceptin. The results support the high potency and antagonist nature of Ac-RYYRIK-ol and reveal important roles for both the N- and the C-terminal region of the molecule.
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Affiliation(s)
- László Kocsis
- Research Group for Peptide Chemistry, Hungarian Academy of Sciences and Department of Organic Chemistry, Eötvös University, P.O. Box 32, Budapest H-1518, Hungary
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19
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Lamb ML, Bradley EK, Beaton G, Bondy SS, Castellino AJ, Gibbons PA, Suto MJ, Grootenhuis PDJ. Design of a gene family screening library targeting G-protein coupled receptors. J Mol Graph Model 2004; 23:15-21. [PMID: 15331050 DOI: 10.1016/j.jmgm.2004.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Revised: 12/15/2003] [Accepted: 03/03/2004] [Indexed: 11/19/2022]
Abstract
An iterative process for the design of a G-protein coupled receptor (GPCR) gene family screening library has been developed. A key element of this process is the computational generation of pharmacophore descriptors of known GPCR ligands. Subsequent iterative analysis allows prioritization of scaffolds and sub-libraries for inclusion in the library. The final library, which consisted of 13,769 compounds, displayed a 2.6% hit rate when screened against the micro-opioid receptor.
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Affiliation(s)
- Michelle L Lamb
- Deltagen Research Laboratories, 740 Bay Rd., Redwood City, CA 94063, USA.
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20
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Abstract
A model for the human delta opioid receptor has been generated via sequence alignment, structure building using the crystal structure of bovine rhodopsin as a template, and refinement by molecular dynamics simulation. The model building suggested that, in addition to the previously postulated interaction between D128 and Y308, an internal salt bridge also exists between residues D128 and R192, both of which are conserved in all the opioid receptors. The model and salt bridge were then shown to be stable during a 20-nsec simulation in a lipid bilayer. It is therefore proposed that both of these interactions play a role in stabilizing the inactive state of the receptor. The model is also used in an effort to rationalize many of the mutational studies performed on delta opioid receptors, and to suggest a plausible explanation for the differences between known delta opioid agonists and antagonists.
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Affiliation(s)
- Mahalaxmi Aburi
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506-3701, USA
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21
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Dolle RE, Machaut M, Martinez-Teipel B, Belanger S, Cassel JA, Stabley GJ, Graczyk TM, DeHaven RN. (4-Carboxamido)phenylalanine is a surrogate for tyrosine in opioid receptor peptide ligands. Bioorg Med Chem Lett 2004; 14:3545-8. [PMID: 15177470 DOI: 10.1016/j.bmcl.2004.04.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2004] [Revised: 04/12/2004] [Accepted: 04/12/2004] [Indexed: 11/20/2022]
Abstract
(S)-4-(Carboxamido)phenylalanine (Cpa) is examined as a bioisosteric replacement for the terminal tyrosine (Tyr) residue in a variety of known peptide ligands for the mu, delta and kappa opioid receptors. The Cpa-containing peptides, assayed against cloned human opioid receptors, display comparable binding affinity (Ki), and agonist potency (EC50) to the parent ligands at the three receptors. Cpa analogs of delta selective peptides show an increase in delta selectivity relative to the mu receptor. Cpa is the first example of an amino acid that acts as a surrogate for Tyr in opioid peptide ligands, challenging the long-standing belief that a phenolic residue is required for high affinity binding.
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MESH Headings
- Amino Acids, Aromatic/chemical synthesis
- Amino Acids, Aromatic/pharmacology
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/pharmacology
- Binding Sites
- Cell Line
- Humans
- Ligands
- Molecular Structure
- Opioid Peptides/metabolism
- Phenol/chemistry
- Phenylalanine/analogs & derivatives
- Phenylalanine/chemical synthesis
- Phenylalanine/pharmacology
- Receptors, Opioid, delta/drug effects
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/metabolism
- Tyrosine/pharmacology
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Affiliation(s)
- Roland E Dolle
- Department of Chemistry, Adolor Corporation, 700 Pennsylvania Drive, Exton, PA 19341, USA.
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22
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Bryant SD, Jinsmaa Y, Salvadori S, Okada Y, Lazarus LH. Dmt and opioid peptides: a potent alliance. Biopolymers 2004; 71:86-102. [PMID: 12767112 DOI: 10.1002/bip.10399] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The introduction of the Dmt (2',6'-dimethyl-L-tyrosine)-Tic pharmacophore into the design of opioid ligands produced an extraordinary family of potent delta-opioid receptor antagonists and heralded a new phase in opioid research. First reviewed extensively in 1998, the incorporation of Dmt into a diverse group of opioid molecules stimulated the opioid field leading to the development of unique analogues with remarkable properties. This overview will document the crucial role played by this residue in the proliferation of opioid peptides with high receptor affinity (K(i) equal to or less than 1 nM) and potent bioactivity. The discussion will include the metamorphosis between delta-opioid receptor antagonists to delta-agonists based solely on subtle structural changes at the C-terminal region of the Dmt-Tic pharmacophore as well as their behavior in vivo. Dmt may be considered promiscuous due to the acquisition of potent mu-agonism by dermorphin and endomorphin derivatives as well as by a unique class of opioidmimetics containing two Dmt residues separated by alkyl or pyrazinone linkers. Structural studies on the Dmt-Tic compounds were enhanced tremendously by x-ray diffraction data for three potent and biologically diverse Dmt-Tic opioidmimetics that led to the development of pharmacophores for both delta-opioid receptor agonists and antagonists. Molecular modeling studies of other unique Dmt opioid analogues illuminated structural differences between delta- and mu-receptor ligand interactions. The future of these compounds as therapeutic applications for various medical syndromes including the control of cancer-associated pain is only a matter of time and perseverance.
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Affiliation(s)
- Sharon D Bryant
- Peptide Neurochemistry, LCBRA, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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23
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Belofsky G, French AN, Wallace DR, Dodson SL. New geranyl stilbenes from Dalea purpurea with in vitro opioid receptor affinity. JOURNAL OF NATURAL PRODUCTS 2004; 67:26-30. [PMID: 14738380 DOI: 10.1021/np030258d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Three new geranyl stilbenes, pawhuskins A, B, and C (1, 2, and 3), were isolated from organic extracts of Dalea purpurea. The structures of the three compounds were determined by NMR and HRMS methods. The activities of these compounds, along with that of the known compound petalostemumol (4), were evaluated in an opioid receptor assay in vitro. Pawhuskin A (1) exhibited the strongest activity of the four compounds with a K(i) value of 0.29 +/- 0.11 microM.
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Affiliation(s)
- Gil Belofsky
- Department of Chemistry and Biochemistry, The University of Tulsa, Tulsa, OK 74101, USA.
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24
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Horton DA, Bourne GT, Smythe ML. Exploring privileged structures: the combinatorial synthesis of cyclic peptides. Mol Divers 2003; 5:289-304. [PMID: 12549678 DOI: 10.1023/a:1021365402751] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Head-to-tail cyclic peptides have been reported to bind to multiple, unrelated classes of receptor with high affinity. They may therefore be considered to be privileged structures. This review outlines the strategies by which both macrocyclic cyclic peptides and cyclic dipeptides or diketopiperazines have been synthesised in combinatorial libraries. It also briefly outlines some of the biological applications of these molecules, thereby justifying their inclusion as privileged structures.
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Affiliation(s)
- Douglas A Horton
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, 4072, Qld., Australia
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25
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Hanessian S, Parthasarathy S, Mauduit M, Payza K. The power of visual imagery in drug design. Isopavines as a new class of morphinomimetics and their human opioid receptor binding activity. J Med Chem 2003; 46:34-48. [PMID: 12502358 DOI: 10.1021/jm020164l] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The importance of visual imagery and relational thinking manifests itself in a heuristic approach to the design and synthesis of potential morphinomimetics as agonists of the human mu receptor. The well-known class of alkaloids represented by the isopavine nucleus has a topological resemblance to the morphine skeleton, especially when viewed in a particular way. Enantiopure isopavines can be readily obtained from a 1,2 Stevens rearrangement of 13-substituted dihydromethanodibenzoazocines, prepared in four steps from d- and l-amino acids. Consideration of the topology and the expected orientation of the nitrogen lone pair for a better overlap with morphine necessitates the utilization of d-amino acids. By variation of the substituents on the aromatic rings and a judicious choice of ring substituents, it is possible to obtain low nanomolar binding to the human mu receptor while maintaining good to excellent mu/delta selectivity. Agonist-like activity is indicated in a functional assay for one of the analogues originally derived from d-alanine as a precursor. X-ray crystal structures of several compounds corroborate stereochemistries and overall topologies.
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MESH Headings
- Azocines/chemical synthesis
- Azocines/chemistry
- Azocines/pharmacology
- Cell Line
- Crystallography, X-Ray
- Drug Design
- Humans
- Molecular Conformation
- Molecular Mimicry
- Morphine Derivatives/chemistry
- Radioligand Assay
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
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Affiliation(s)
- Stephen Hanessian
- Department of Chemistry, Université de Montréal, Succersale Centre-Ville, Montréal, Québec, Canada.
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26
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Horton DA, Bourne GT, Smythe ML. Exploring privileged structures: the combinatorial synthesis of cyclic peptides. J Comput Aided Mol Des 2002; 16:415-30. [PMID: 12489688 DOI: 10.1023/a:1020863921840] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Head-to-tail cyclic peptides have been reported to bind to multiple, unrelated classes of receptor with high affinity. They may therefore be considered to be privileged structures. This review outlines the strategies by which both macrocyclic cyclic peptides and cyclic dipeptides or diketopiperazines have been synthesised in combinatorial libraries. It also briefly outlines some of the biological applications of these molecules, thereby justifying their inclusion as privileged structures.
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Affiliation(s)
- Douglas A Horton
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, 4072, Qld., Australia
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27
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Eguchi M, Shen RYW, Shea JP, Lee MS, Kahn M. Design, synthesis, and evaluation of opioid analogues with non-peptidic beta-turn scaffold: enkephalin and endomorphin mimetics. J Med Chem 2002; 45:1395-8. [PMID: 11906279 DOI: 10.1021/jm0155897] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have identified a mu-selective opioid receptor agonist without a cationic amino group in the molecule from libraries of bicyclic beta-turn peptidomimetics. The biologically active conformation of the lead is proposed to mimic an endomorphin type III 4 --> 1 beta-turn conformation.
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28
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Abstract
Peptide recognition by G-protein coupled receptors (GPCRs) is reviewed with an emphasis on the indirect approach used to determine the receptor-bound conformation of peptide ligands. This approach was developed in response to the lack of detailed structural information available for these receptors. Recent advances in the structural determination of rhodopsin (the GPCR of the visual system) by crystallography have provided a scaffold for homology modeling of the inactive state of a wide variety of GPCRs that interact with peptide messages. Additionally, the ability to mutate GPCRs and assay compounds of similar chemical structure to test a common binding site on the receptor provides a firm experimental basis for structure-activity studies. Recognition motifs, common in other well-studied systems such as proteolytic enzymes and major histocompatibility class receptors (MHC) are reviewed briefly to provide a basis of comparison. Finally, the development of true peptidomimetics is contrasted with nonpeptide ligands, discovered through combinatorial chemistry. In many systems, the evidence suggests that the peptide ligands bind at the interface between the transmembrane segments and the extracellular loops, while nonpeptide antagonists bind within the transmembrane segments. Plausible models of GPCRs and the mechanism by which they activate G-proteins on binding peptides are beginning to emerge.
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Affiliation(s)
- G R Marshall
- Center for Computational Biology, 700 S. Euclid Avenue, Washington University, St. Louis, MO 63110, USA.
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29
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Balboni G, Guerrini R, Salvadori S, Bianchi C, Rizzi D, Bryant SD, Lazarus LH. Evaluation of the Dmt-Tic pharmacophore: conversion of a potent delta-opioid receptor antagonist into a potent delta agonist and ligands with mixed properties. J Med Chem 2002; 45:713-20. [PMID: 11806723 DOI: 10.1021/jm010449i] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analogues of the 2',6'-dimethyl-L-tyrosine (Dmt)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) pharmacophore were prepared to test the hypothesis that a "spacer" and a third aromatic center in opioid peptides are required to convert a delta-antagonist into ligands with delta-agonist or with mixed delta-antagonist/mu-agonist properties. Potent delta-agonists and bifunctional compounds with high delta- and mu-opioid receptor affinities were obtained by varying the spacer length [none, NH-CH(2), NH-CH(2)-CH(2), Gly-NH-CH(2)] and C-terminal aromatic nucleus [1H-benzimidazole-2-yl, phenyl (Ph) and benzyl groups]. C-terminal modification primarily affected mu-opioid receptor affinities, which increased maximally 1700-fold relative to the prototype delta-antagonist H-Dmt-Tic-NH(2) and differentially modified bioactivity. In the absence of a spacer (1), the analogue exhibited dual delta-agonism (pEC(50), 7.28) and delta-antagonism (pA(2), 7.90). H-Dmt-Tic-NH-CH(2)-1H-benzimidazole-2-yl (Bid) (2) became a highly potent delta-agonist (pEC(50), 9.90), slightly greater than deltorphin C (pEC(50), 9.56), with mu-agonism (pE(50), 7.57), while H-Dmt-Tic-Gly-NH-CH(2)-Bid (4) retained potent delta-antagonism (pA(2), 9.0) but with an order of magnitude less mu-agonism. Similarly, H-Dmt-Tic-Gly-NH-Ph (5) had nearly equivalent high delta-agonism (pEC(50), 8.52) and mu-agonism (pEC(50), 8.59), while H-Dmt-Tic-Gly-NH-CH(2)-Ph (6) whose spacer was longer by a single methylene group exhibited potent delta-antagonism (pA(2), 9.25) and very high mu-agonism (pEC(50), 8.57). These data confirm that the distance between the Dmt-Tic pharmacophore and a third aromatic nucleus is an important criterion in converting Dmt-Tic from a highly potent delta-antagonist into a potent delta-agonist or into ligands with mixed delta- and mu-opioid properties.
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Affiliation(s)
- Gianfranco Balboni
- Department of Toxicology, University of Cagliary, I09126 Cagliary, Italy
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30
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Burden JE, Davis P, Porreca F, Spatola AF. Synthesis and biological activities of YkFA analogues: effects of position 4 substitutions and altered ring size on in vitro opioid activity. Bioorg Med Chem Lett 2002; 12:213-6. [PMID: 11755357 DOI: 10.1016/s0960-894x(01)00706-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Substitution in position 4 of the potent opioid peptide YkFA with aliphatic hydrophobic residues resulted in compounds that retained low nanomolar activities at both mu and delta opioid receptors, while ring contraction by incorporation of diaminobutyric acid in position 2 resulted in a more pronounced decrease in potency at both receptors for the psi[CH(2)NH] pseudopeptide as compared to the all amide parent.
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Affiliation(s)
- John E Burden
- Department of Chemistry, University of Louisville, Louisville, KY 40292, USA
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31
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Lu Y, Nguyen TM, Weltrowska G, Berezowska I, Lemieux C, Chung NN, Schiller PW. [2',6'-Dimethyltyrosine]dynorphin A(1-11)-NH2 analogues lacking an N-terminal amino group: potent and selective kappa opioid antagonists. J Med Chem 2001; 44:3048-53. [PMID: 11543672 DOI: 10.1021/jm0101186] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent studies showed that dermorphin and enkephalin analogues containing two methyl groups at the 2',6'-positions of the Tyr(1) aromatic ring and lacking an N-terminal amino group were moderately potent delta and mu opioid antagonists. These results indicate that a positively charged N-terminal amino group may be essential for signal transduction but not for receptor binding and suggested that its deletion in agonist opioid peptides containing an N-terminal 2',6'-dimethyltyrosine (Dmt) residue may represent a general way to convert them into antagonists. In an attempt to develop dynorphin A (Dyn A)-derived kappa opioid antagonists, we prepared analogues of [Dmt(1)]Dyn A(1-11)-NH2 (1), in which the N-terminal amino group was either omitted or replaced with a methyl group. This was achieved by replacement of Tyr(1) with 3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid (Dhp) or (2S)-2-methyl-3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid [(2S)-Mdp]. Compounds were tested in the guinea pig ileum and mouse vas deferens bioassays and in rat and guinea pig brain membrane receptor binding assays. All analogues turned out to be potent kappa antagonists against Dyn A(1-13) and the non-peptide agonist U50,488 and showed only weak mu and delta antagonist activity. The most potent and most selective kappa antagonist of the series was [(2S)-Mdp(1)]Dyn A(1-11)-NH2 (5, dynantin), which showed subnanomolar kappa antagonist potency against Dyn A(1-13) and very high kappa selectivity both in terms of its K(e) values determined against kappa, mu, and delta agonists and in terms of its ratios of kappa, mu, and delta receptor binding affinity constants. Dynantin is the first potent and selective Dyn A-derived kappa antagonist known and may complement the non-peptide kappa antagonists norbinaltorphimine and GNTI as a pharmacological tool in opioid research.
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Affiliation(s)
- Y Lu
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec, H2W 1R7, Canada
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32
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Lu Y, Weltrowska G, Lemieux C, Chung NN, Schiller PW. Stereospecific synthesis of (2S)-2-methyl-3-(2',6'-dimethyl-4'-hydroxyphenyl)-propionic acid (Mdp) and its incorporation into an opioid peptide. Bioorg Med Chem Lett 2001; 11:323-5. [PMID: 11212101 DOI: 10.1016/s0960-894x(00)00660-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To examine the effect of replacing the N-terminal amino group in opioid peptides with a methyl group on biological activity, a stereospecific synthesis of the tyrosine analogue (2S)-2-methyl-3-(2',6'-dimethyl-4'-hydroxyphenyl)-propionic acid (Mdp) was performed. The enkephalin analogue (2S)-Mdp-D-Ala-Gly-Phe-Leu-NH2 turned out to be a quite potent delta opioid antagonist and a somewhat less potent mu antagonist, indicating that a positively charged N-terminal amino group is not a conditio sine qua non for the binding of opioid peptides to delta and mu receptors but may be required for signal transduction.
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Affiliation(s)
- Y Lu
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, Quebec, Canada
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33
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34
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Abstract
Previously 2,4-dipyridine substituted 3,7-diazabicyclo[3.3.1]nonanone diesters were found to have a high affinity and selectivity towards the kappa-opioid receptor. The purpose of this study was to check the influence of substituents at position N3 on the affinity to the mu-, delta-, and kappa-receptors. Whereas a phenylethyl group is able to create affinity to the mu-receptor, small substituents such as a hydrogen or a methyl group are responsible for a high affinity to the kappa-receptor. In addition, a dimeric compound was found to have affinity to the kappa-receptor. Although all compounds will bear at least one positive charge under physiological conditions they show a considerable lipophilicity, indicating the possibility of passing the blood-brain barrier.
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Affiliation(s)
- U Kuhl
- Institut für Pharmazie und Lebensmittelchemie, Universität Würzburg, Germany
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