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Li W, Wang XH, Lau CW, Tang Y, Xie Q, Qiu ZB. Conformational re-analysis of (+)-meptazinol: an opioid with mixed analgesic pharmacophores. Acta Pharmacol Sin 2006; 27:1247-52. [PMID: 16923347 DOI: 10.1111/j.1745-7254.2006.00375.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIM To further investigate the analgesic pharmacophore of (+)-meptazinol. METHODS Two different opioid pharmacophores, Pharm-I and Pharm-II, were established from structures of nine typical opiates and meperidine by using molecular modeling approaches according to their different structure activity relationship properties. They were further validated by a set of conformationally constrained arylpiperidines. Two conformers of (+)-meptazinol (Conformer-I and Conformer-II) detected in solution were then fitted into the pharmacophores, respectively, by Fit Atoms facilities available in SYBYL, a computational modeling tool kit for molecular design and analysis. RESULTS Conformer-I fit Pharm-I from typical opiates well. However, Conformer-II fit none of these pharmacophores. Instead, it was found to be similar to another potent analgesic, benzofuro[2,3-c]pyridin-6-ol, whose pharmacophore was suggested to hold the transitional state between the two established pharmacophores. Unlike typical analgesics derived from 4-aryl piperidine (eg, meperidine) with one conformer absolutely overwhelming, the (+)-meptazinol exists in two conformers with similar amounts in solution. Furthermore, both conformers can not transform to each other freely in ordinary conditions based on our NMR results. CONCLUSION (+)-meptazinol was suggested to be an opioid with mixed analgesic pharmacophores, which may account for the complicated pharmacological properties of meptazinol.
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Affiliation(s)
- Wei Li
- Department of Medicinal Chemistry, Fudan University, Shanghai 200032, China
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2
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Kuz’mina NE, Osipova ES, Kuz’min VS, Sitnikov VB. A general model of the opiate pharmacophore 1. Regions of the opiate pharmacophore responsible for nonselective affinity for the opiate receptor. Russ Chem Bull 2006. [DOI: 10.1007/s11172-006-0450-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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3
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Li W, Tang Y, Xie Q, Sheng W, Qiu ZB. 3D–QSAR studies of orvinol analogs as κ-opioid agonists. J Mol Model 2006; 12:877-84. [PMID: 16552460 DOI: 10.1007/s00894-005-0084-9] [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: 04/14/2005] [Accepted: 11/11/2005] [Indexed: 11/27/2022]
Abstract
Orvinols are potent analgesics that target opioid receptors. However, their analgesic mechanism remains unclear and no significant preference for subtype opioid receptor has been achieved. In order to find new orvinols that target the kappa-receptor, comparative 3D-QSAR studies were performed on 26 orvinol analogs using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The best predictions for the kappa-receptor were obtained with the CoMFA standard model (q2 = 0.686, r2 = 0.947) and CoMSIA model combined steric, electrostatic, hydrophobic, and hydrogen bond donor/acceptor fields (q2 = 0.678, r2 = 0.914). The models built were further validated by a test set made up of seven compounds, leading to predictive r2 values of 0.672 for CoMFA and 0.593 for CoMSIA. The study could be helpful for designing and prepare new category kappa-agonists from orvinols.
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Affiliation(s)
- Wei Li
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China
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Li W, Hao JL, Tang Y, Chen Y, Qiu ZB. Structural comparisons of meptazinol with opioid analgesics. Acta Pharmacol Sin 2005; 26:334-8. [PMID: 15715930 DOI: 10.1111/j.1745-7254.2005.00045.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
AIM To investigate the mechanism of action of a potent analgesic, (+/-)-meptazinol. METHODS The structures of meptazinol enantiomers were compared with opioid pharmacophore and tramadol. RESULTS Neither enantiomer of meptazinol fitted any patterns among the opioid pharmacophore and tramadol, although they did share some structural and pharmacological similarities. However, the structure superpositions implied that both enantiomers of meptazinol might share some similar analgesic mechanisms with typical opiate analgesics. CONCLUSION Meptazinol should have a different mechanism of action to known analgesics, which would be helpful in further investigations of meptazinol in the search for non-addictive analgesics.
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Affiliation(s)
- Wei Li
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai 200032, China
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Sakurada C, Sakurada S, Hayashi T, Katsuyama S, Tan-No K, Sakurada T. Degradation of endomorphin-2 at the supraspinal level in mice is initiated by dipeptidyl peptidase IV: an in vitro and in vivo study. Biochem Pharmacol 2003; 66:653-61. [PMID: 12906930 DOI: 10.1016/s0006-2952(03)00391-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Endomorphin-2 (Tyr-Pro-Phe-PheNH(2)) was discovered as an endogenous ligand for the mu-opioid receptor. The physiological function of endomorphin-2 as a neurotransmitter or neuromodulator may cease through the rapid enzymatic process in the synapse of brain, as for other neuropeptides. The present study was conducted to examine the metabolism of endomorphin-2 by synaptic membranes prepared from mouse brain. Major metabolites were free tyrosine, free phenylalanine, Tyr-Pro and PheNH(2). Both the degradation of endomorphin-2 and the accumulation of major metabolites were inhibited by specific inhibitors of dipeptidyl peptidase IV, such as diprotin A and B. On the other hand, the accumulation of Phe-PheNH(2) and Pro-Phe-PheNH(2) was increased in the presence of bestatin, an aminopeptidase inhibitor, whereas that of free phenylalanine and PheNH(2) was decreased. Furthermore, purified dipeptidyl peptidase IV hydrolyzed endomorphin-2 at the cleavage site, Pro(2)-Phe(3) bond. Thus, degradation of endomorphin-2 by brain synaptic membranes seems to take place mainly through the cleavage of Pro(2)-Phe(3) bond by dipeptidyl peptidase IV, followed by release of free phenylalanine and PheNH(2) from the liberated fragment, Phe-PheNH(2) by aminopeptidase. We have also examined that the effect of diprotin A on the antinociception induced by intracerebroventricularly administered endomorphin-2 in the mouse paw withdrawal test. Diprotin A simultaneously injected with endomorphin-2 enhanced endomorphin-2-induced antinociception. These results indicate that dipeptidyl peptidase IV may be an important peptidase responsible for terminating endomorphin-2-induced antinociception at the supraspinal level in mice.
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Affiliation(s)
- Chikai Sakurada
- Department of Biochemistry, Daiichi College of Pharmaceutical Sciences, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
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Szatmári I, Biyashev D, Tömböly C, Tóth G, Mácsai M, Szabó G, Borsodi A, Lengyel I. Influence of degradation on binding properties and biological activity of endomorphin 1. Biochem Biophys Res Commun 2001; 284:771-6. [PMID: 11396969 DOI: 10.1006/bbrc.2001.5056] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recently-isolated endogenous peptide endomorphin 1 has high affinity for the mu opioid receptor and plays an important role in analgesia. Several of its degradation products have been isolated from the central nervous system. Degradation products present structural similarities and may influence the receptor binding properties and biological activity of the parent compound. Therefore, we investigated how degradation of endomorphin 1 might influence ligand binding to the mu opioid receptor, the consequent activation of G proteins and its antinociceptive effect. Both N- and C-terminal truncation of endomorphin 1 resulted in peptides presenting considerably lower opioid receptor binding potency. None of these peptides had an effect on GTP binding, nor was able to produce analgesia, suggesting that degradation destroys the biological activity of endomorphin 1.
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Affiliation(s)
- I Szatmári
- Institute of Biochemistry Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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Rónai AZ, Botyánszki J, Hepp J, Medzihradszky K. A novel opioid structure which accepts protonated as well as non-protonated nitrogen: a family of pure, delta receptor selective antagonists. Life Sci 1992; 50:1371-8. [PMID: 1313941 DOI: 10.1016/0024-3205(92)90288-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Conventional opioids including opioid peptides require an "opioid" nitrogen which exists in protonated state while interacting with the receptor. In the present paper we demonstrate that the Tyr-Pro-Gly-Phe-Leu-Thr hexapeptide sequence accepts N-terminal substituents such as N-t-Boc, N-phenylacetyl and N-diphenylacetyl where the N cannot become protonated, as well as "traditional" substitutions such as N,N-diallyl, where protonation is likely under physiological conditions. The opioid peptides bearing these substituents are pure antagonists of medium affinity (Ke values in the mouse vas deferens bioassay against [Met5]-enkephalin are in the 3 x 10(-7)-4 x 10(-6) M range) with a high delta receptor preference (50-350-fold delta over mu selectivity ratios).
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Affiliation(s)
- A Z Rónai
- Department of Organic Chemistry, L. Eötvös University, Budapest, Hungary
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9
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Abstract
Peptides can be transported across the blood-brain barrier by saturable transport systems. One system, characterized with radioactively labeled Tyr-MIF-1 (Tyr-Pro-Leu-Gly-amide), is specific for some of the small peptides with an N-terminal tyrosine, including Tyr-MIF-1, the enkephalins, beta-casomorphin, and dynorphin (1-8). Another separate system transports vasopressin-like peptides. The choroid plexus has at least one system distinguishable from those above that is capable of uptake and possibly transport of opiate-like peptides. The possibility of saturable transport of other peptides has been investigated to a varying degree. Specificity, stereo-specificity, saturability, allosteric regulation, modulation by physiologic and pharmacologic manipulations, and noncompetitive inhibition have been demonstrated to occur in peptide transport systems and suggest a role for them in physiology and disease.
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Abstract
Extensive conformational calculations were performed on the potent opiate analgesics etorphine, PET, R30490 and etonitazene to determine all of their many low-energy conformations. The results were used to characterize four possible models for binding of a simple pharmacophore, comprising two phenyl rings plus a protonated nitrogen, to opiate analgesic receptors. These four models may define the necessary three-dimensional features leading to particular opiate actions. The model favoured for mu receptor activity can accommodate a protonated nitrogen, an aromatic ring (which may be substituted with an electronegative group) and a second lipophilic group. These structural features must be presented in a precise three-dimensional arrangement. It appears likely that a hydrophilic substituent in a certain region of the analgesic pharmacophore may also interact with the receptor as a secondary binding group.
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Affiliation(s)
- J Martin
- School of Pharmaceutical Chemistry, Victorian College of Pharmacy Ltd., Parkville, Australia
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11
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Banks WA, Kastin AJ, Fischman AJ, Coy DH, Strauss SL. Carrier-mediated transport of enkephalins and N-Tyr-MIF-1 across blood-brain barrier. THE AMERICAN JOURNAL OF PHYSIOLOGY 1986; 251:E477-82. [PMID: 2876644 DOI: 10.1152/ajpendo.1986.251.4.e477] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The saturable, carrier-mediated system capable of the brain-to-blood transport of small peptides with an N-terminal tyrosine was characterized. The rate of disappearance of intraventricularly injected iodinated peptide in the presence or absence of the inhibitor being tested was determined from formulas based on the residual radioactivity in the brains of mice after decapitation. The injection of 100 nmol/mouse of unlabeled N-Tyr-MIF-1 (TMIF) increased the half-time disappearance of 125I-TMIF (ITMIF) in the central nervous system (CNS) from 14.1 to 88.7 min (P less than 0.00005). Technetium, a substance transported out of the brain by the same system that transports iodine, was used as a control; the half-time disappearance of technetium pertechnetate was unaffected by unlabeled TMIF. With two related but distinct techniques, the maximum transport rate out of the CNS (Vmax) for TMIF was 0.266 nmol X g of brain per min (method 1) and 0.297 nmol X g-1 X min-1 (method 2), while the amount of unlabeled material needed to achieve 50% of Vmax (Km) was 15.2 nmol/g (method 1) and 15.1 nmol/g (method 2). The lack of effect of the tyrosinated fragments of TMIF as inhibitors indicates that TMIF is being transported in intact form. The Vmax for methionine enkephalin determined with labeled and unlabeled methionine enkephalin was 0.630 nmol X g-1 X min-1 and the Km was 24.95 nmol/g. Studies with the metabolic modulators furosemide, acetozolamide, reserpine, ouabain, and theophylline suggest that the system is sodium dependent and probably independent of ATPase.(ABSTRACT TRUNCATED AT 250 WORDS)
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Andrews PR, Lloyd EJ. Common structural features of drugs, transmitters and peptides in the central nervous system. PROGRESS IN MEDICINAL CHEMISTRY 1986; 23:91-119. [PMID: 2889242 DOI: 10.1016/s0079-6468(08)70341-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Ishida T, Kenmotsu M, Mino Y, Inoue M, Fujiwara T, Tomita K, Kimura T, Sakakibara S. X-ray diffraction studies of enkephalins. Crystal structure of [(4'-bromo) Phe4,Leu5]enkephalin. Biochem J 1984; 218:677-89. [PMID: 6721829 PMCID: PMC1153395 DOI: 10.1042/bj2180677] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In order to investigate the structure-activity relationship of [Leu5]- and [Met5]enkephalins, [(4'-bromo)Phe4, Leu5]-, [(4'-bromo)Phe4, Met5]- and [Met5] enkephalins were synthesized and crystallized. The crystal structure of [(4'-bromo) Phe4, Leu5]- enkephalin was determined by X-ray diffraction method using the heavy atom method and refined to R = 0.092 by the least-squares method. The molecule in this crystal took essentially the same type I' beta-turn conformation found in [Leu5]enkephalin [Smith & Griffin (1978) Science 199, 1214-1216). On the other hand, the preliminary three-dimensional Patterson analyses showed that the most probable conformations of [(4'-bromo)Phe4,Met5]- and [Met5]enkephalins are both the dimeric extended forms. Based on these insights, the biologically active conformation of enkephalin was discussed in relation to the mu- and delta-receptors.
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14
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Andrews PR, Lloyd EJ. Molecular conformation and biological activity of central nervous system active drugs. Med Res Rev 1982; 2:355-93. [PMID: 6129361 DOI: 10.1002/med.2610020404] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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15
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Shaw JS, Miller L, Turnbull MJ, Gormley JJ, Morley JS. Selective antagonists at the opiate delta-receptor. Life Sci 1982; 31:1259-62. [PMID: 6128652 DOI: 10.1016/0024-3205(82)90356-3] [Citation(s) in RCA: 148] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Lipkowski AW, Konecka AM, Sroczyńska I. Double-enkephalins--synthesis, activity on guinea-pig ileum, and analgesic effect. Peptides 1982; 3:697-700. [PMID: 7134034 DOI: 10.1016/0196-9781(82)90173-5] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We have synthesized enkephalin analogues in which C-terminal methionine or leucine residues are replaced by a second active fragment of the enkephalin analogue. Synthesis of two compounds is described: in one, two fragments of a D-Ala2-enkephalin analogue are connected by a -NH-NH-bridge, and in the other, three methylene groups are incorporated between the amino groups. The first compound is a very potent inhibitor of electrically induced contractions of guinea-pig ileum and produces a strong analgesia when administered intraperitoneally in mice. The second compound is less active on the ileum and fails to produce analgesia after systemic injection. The double-enkephalins may interact with mu-receptors.
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Maigret B, Premilat S, Fournie-Zaluski MC, Roques BP. Proposals for conformation of enkephalins related to opiate mu-pharmacophore. Biochem Biophys Res Commun 1981; 99:267-74. [PMID: 6263272 DOI: 10.1016/0006-291x(81)91741-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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18
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Ezhov VV, Potashnikov PF, Sokol'skii GA. Bioactivity as a function of structure. Pharm Chem J 1980. [DOI: 10.1007/bf00765662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nakamura H, Ishii D, Yokoyama Y, Motoyoshi S, Natsuka K, Shimizu M. Analgesic and other pharmacological activities of a new narcotic antagonist analgesic (-)-1-(3-methyl-2-butenyl)-4-[2-(3-hydroxyphenyl)-1-phenylethyl]-piperazine and its enantiomorph in experimental animals. J Pharm Pharmacol 1980; 32:635-42. [PMID: 6107365 DOI: 10.1111/j.2042-7158.1980.tb13020.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Of 1-chclohexyl-4-[2-(3-hydroxyphenyl)-1-phenylethyl]piperazine (I) and its 1-(3-methyl-2-butenyl) derivative (II), the S(+)-isomers were analgesically more active than either their +(-)-isomers or their racemates, having 15 to 44 times the potency of morphine in mice and rats. R(-)-I had comparable analgesic activity to morphine R(-)-II to pentazocine in mice, rats and dogs and they were nearly equipotent with pentazocine in reversing some actions of morphine. The S(+)-isomers and racemates lacked this action. R(-)-II required about 10 times more naloxone to reverse its analgesic activity than was needed to antagonise the S(+)-isomers, morphine and pentazocine. The S(+)-isomers and racemates produce a typical Straub tail reaction and increased spontaneous locomotor activity in mice, but the R(-)-isomers did not. R(-)-II had no significant physical dependence liability in mice, rats and monkeys. From these results, it is suggested that the compounds show an uncommon steroselectivity in comparison with morphine and its surrogates, and that R(-)-II is worth investigating further as a narcotic antagonist analgesic.
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Horn AS, Rodgers JR. 2-amino-6,7-dihydroxytetrahydronaphthalene and the receptor-site preferred conformation of dopamine--a commentary. J Pharm Pharmacol 1980; 32:521-4. [PMID: 6105198 DOI: 10.1111/j.2042-7158.1980.tb12987.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Beddell CR, Lowe LA, Wilkinson S. Endogenous opioid peptides--the enkephalins and endorphins. PROGRESS IN MEDICINAL CHEMISTRY 1980; 17:1-39. [PMID: 6273969 DOI: 10.1016/s0079-6468(08)70156-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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22
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Rónai AZ, Székely JI, Berzétei I, Miglécz E, Bajusz S. Tetrapeptide-amide analogues of enkephalin: the role of C-terminus in determining the character of opioid activity. Biochem Biophys Res Commun 1979; 91:1239-49. [PMID: 526300 DOI: 10.1016/0006-291x(79)91200-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Quinn MJ, Laska FJ, Fennessy MR. Structure-activity relationships of met5- and leu5-enkephalin analogues. Clin Exp Pharmacol Physiol 1979; 6:535-40. [PMID: 498593 DOI: 10.1111/j.1440-1681.1979.tb00036.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
1. The effect of various analogues of met5- and leu5-enkephalin were determined on the reduction in twitch height of the electrically-stimulated longitudinal muscle preparation of the guinea-pig ileum and of the isolated mouse vas deferens. 2. In the guinea-pig ileum, D-alanine2-met5-enkephalin was the most potent whereas leu5-enkephalin was the most potent in the mouse vas deferens. 3. The met5-enkephalin analogues were more effective in reducing the twitch height of the ileum than they were in depressing that of the vas deferens preparation. The leu5-enkephalin analogues were more potent in their effects on the mouse vas deferens than they were on the guinea-pig ileum. 4. When a peptide bond is replaced by a glycol bond as in glycol2-3-leu5-enkephalin there is a marked reduction in opiate-like activity. 5. Substitution of a D-alanine residue for the glycine2 residue, as in D-alanine2-met5-enkephalin, increases the duration and potency of opiate-like activity. 6. These results confirm that modification of either met5- or leu5-enkephalin can alter the opiate-like potency of the resulting analogues. It appears that an intact tyrosyl residue of leu5-enkephalin is essential for such activity and that substitution of a D-alanine2 residue for the glycine2 residue confers resistance to enzymatic degradation on the met5-enkephalin peptide. In addition, the glycine2-3 peptide bond is essential for opiate-like activity.
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Childers SR, Creese I, Snowman AM, Synder SH. Opiate receptor binding affected differentially by opiates and opioid peptides. Eur J Pharmacol 1979; 55:11-8. [PMID: 220062 DOI: 10.1016/0014-2999(79)90142-0] [Citation(s) in RCA: 138] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The potencies of various opiates in displacing several 3H-opiate ligands' binding to rat membranes vary depending on the nature of the ligand. Whereas opiate antagonists, as well as the opioid peptides and some agonists (etorphine, levorphanol and phenazocine) display similar affinities in displacing either 3H-opiate or 3H-methionine enkephalin binding, other agonists (such as morphine and oxymorphone) are considerably (20-50 times) weaker in displacing 3H-enkephalin than 3H-dihydromorphine binding. These agonists also compete for 3H-enkephalin binding with shallow displacement curves, and are greatly weakened in displacing 3H-naloxone binding in the presence of sodium. These agonists differ from the other opiate classes by possessing a relatively hydrophilic component in their C-ring moieties which may provide a basis for the differential interactions of drugs with the opiate receptor.
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Pless J, Bauer W, Cardinaux F, Closse A, Hauser D, Huguenin R, Roemer D, Buescher HH, Hill RC. Synthesis, Opiate Receptor Binding and Analgesic Activity of Enkephalin Analogues. Helv Chim Acta 1979. [DOI: 10.1002/hlca.19790620206] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Gacel G, Fournié-Zaluski MC, Fellion E, Roques BP, Senault B, Lecomte JM, Malfroy B, Swerts JP, Schwartz JC. Conformation and biological activities of hexapeptides related to enkephalins: respective roles of the ammonium and hydroxyl groups of tyrosine. Life Sci 1979; 24:725-31. [PMID: 440018 DOI: 10.1016/0024-3205(79)90354-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Huang JT, Lajtha A. The accumulation of (3H) enkephalinamide (2-D-alanine-5-methioninamide) in rat brain tissues. Neuropharmacology 1978; 17:1075-9. [PMID: 745697 DOI: 10.1016/0028-3908(78)90044-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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28
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Kamikawa Y, Shimo Y. Antagonistic effect of compound 48/80 on the inhibitory actions of morphine and methionine-enkephalin on electrically-induced contractions of the guinea-pig ileum. Br J Pharmacol 1978; 64:511-8. [PMID: 728680 PMCID: PMC1668447 DOI: 10.1111/j.1476-5381.1978.tb17312.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
1 The effect of compound 48/80 was studied on the twitch-like contractions of the longitudinal muscle of guinea-pig ileum induced by electrical stimulation of intramural cholinergic nerves. 2 Compound 48/80 alone, at concentrations up to 30 microgram/ml, had no effect on the twitch contractions. The contraction to exogenously applied acetylcholine was slightly depressed by the compound. 3 At 100 microgram/ml, compound 48/80 caused a weak but long-lasting increase in tone and irregular contractile activity in the ileum, part of which was reduced but not completely abolished by pretreatment with chlorpheniramine (1 muM) or by repeated applications of compound 48/80. 4 The inhibitory effects of morphine and methionine-enkephalin on the twitches were antagonized by the presence of compound 48/80 (3 to 30 microgram/ml), possibly in a competitive manner. The antagonism was not affected by pretreatment with the antihistaminics, chlorpheniramine and/or metiamide. 5 The inhibitory effects of noradrenaline and adrenaline on the twitches were slightly but significantly increased by the presence of compound 48/80 (10 or 30 microgram/ml), whereas that of ATP was not modified. 6 Thesese results indicate that compound 48/80 acts as a selective and competitive antagonist at opiate receptors located in the intramural cholinergic nerves of guinea-pig ileum.
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Maryanoff BE, Zelesko MJ. Stereochemical considerations in structural comparison of enkephalins and endorphins with exogenous opiate agents. J Pharm Sci 1978; 67:590-1. [PMID: 641783 DOI: 10.1002/jps.2600670448] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Balodis YY, Nikiforovich GV, Grinsteine IV, Vegner RE, Chipens GI. Enkephalin: structure--function relationships. FEBS Lett 1978; 86:239-42. [PMID: 203486 DOI: 10.1016/0014-5793(78)80570-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Casy AF. Analgesics and their antagonists: recent developments. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 1978; 22:149-227. [PMID: 360283 DOI: 10.1007/978-3-0348-7102-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Britton DR, Fertel R, Coy DH, Kastin AJ. Effect of enkephalin and endorphin analogs on receptors in the mouse vas deferens. Biochem Pharmacol 1978; 27:2275-7. [PMID: 215153 DOI: 10.1016/0006-2952(78)90088-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Marshall GR, Gorin FA, Moore ML. Chapter 24. Peptide Conformation and Biological Activity. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 1978. [DOI: 10.1016/s0065-7743(08)60627-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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Gorin FA, Balasubramanian TM, Barry CD, Marshall GR. Elucidation of the receptor-bound conformation of the enkephalins. JOURNAL OF SUPRAMOLECULAR STRUCTURE 1978; 9:27-39. [PMID: 743340 DOI: 10.1002/jss.400090104] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The biologically relevant conformers of enkephalin predicted by solid state, solution state, and theoretical energy studies have been compared with the published structure-activity data on these compounds. No conformational technique proposes a model consistent with all the pharmacological data; the shortcomings of each approach are evaluated. An alternative approach, which correlates the structure-activity data of opiate compounds with that of the enkephalins, is described and shown to produce a model consistent with the available structure-activity data.
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