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Guillory X, Wolter M, Leysen S, Neves JF, Kuusk A, Genet S, Somsen B, Morrow JK, Rivers E, van Beek L, Patel J, Goodnow R, Schoenherr H, Fuller N, Cao Q, Doveston RG, Brunsveld L, Arkin MR, Castaldi P, Boyd H, Landrieu I, Chen H, Ottmann C. Fragment-based Differential Targeting of PPI Stabilizer Interfaces. J Med Chem 2020; 63:6694-6707. [PMID: 32501690 PMCID: PMC7356319 DOI: 10.1021/acs.jmedchem.9b01942] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Stabilization of protein-protein interactions (PPIs) holds great potential for therapeutic agents, as illustrated by the successful drugs rapamycin and lenalidomide. However, how such interface-binding molecules can be created in a rational, bottom-up manner is a largely unanswered question. We report here how a fragment-based approach can be used to identify chemical starting points for the development of small-molecule stabilizers that differentiate between two different PPI interfaces of the adapter protein 14-3-3. The fragments discriminately bind to the interface of 14-3-3 with the recognition motif of either the tumor suppressor protein p53 or the oncogenic transcription factor TAZ. This X-ray crystallography driven study shows that the rim of the interface of individual 14-3-3 complexes can be targeted in a differential manner with fragments that represent promising starting points for the development of specific 14-3-3 PPI stabilizers.
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Affiliation(s)
- Xavier Guillory
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Madita Wolter
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Seppe Leysen
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - João Filipe Neves
- CNRS ERL9002 Integrative Structural Biology F-59000 Lille, France.,Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE, Risk Factors and Molecular Determinants of Aging-Related Diseases, F-59000 Lille, France
| | - Ave Kuusk
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.,Hit Discovery, Discovery Sciences, Biopharmaceutical R&D, AstraZeneca, Gothenburg, 431 50 Mölndal, Sweden
| | - Sylvia Genet
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Bente Somsen
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - John Kenneth Morrow
- Department of Pharmaceutical Chemistry and Small Molecule Discovery Center (SMDC), University of California, San Francisco, California 94143, United States
| | - Emma Rivers
- Hit Discovery, Discovery Sciences, Biopharmaceutical R&D, AstraZeneca, Gothenburg, 431 50 Mölndal, Sweden
| | - Lotte van Beek
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Joe Patel
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Robert Goodnow
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Heike Schoenherr
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Nathan Fuller
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Qing Cao
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Richard G Doveston
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Luc Brunsveld
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
| | - Michelle R Arkin
- Department of Pharmaceutical Chemistry and Small Molecule Discovery Center (SMDC), University of California, San Francisco, California 94143, United States
| | - Paola Castaldi
- Oncology and Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Helen Boyd
- Hit Discovery, Discovery Sciences, Biopharmaceutical R&D, AstraZeneca, Gothenburg, 431 50 Mölndal, Sweden
| | - Isabelle Landrieu
- CNRS ERL9002 Integrative Structural Biology F-59000 Lille, France.,Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167-RID-AGE, Risk Factors and Molecular Determinants of Aging-Related Diseases, F-59000 Lille, France
| | - Hongming Chen
- Hit Discovery, Discovery Sciences, Biopharmaceutical R&D, AstraZeneca, Gothenburg, 431 50 Mölndal, Sweden
| | - Christian Ottmann
- Laboratory of Chemical Biology, Department of Biomedical Engineering and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.,Department of Organic Chemistry, University of Duisburg-Essen, 47057 Duisburg, Germany
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Satz AL, Cai J, Chen Y, Goodnow R, Gruber F, Kowalczyk A, Petersen A, Naderi-Oboodi G, Orzechowski L, Strebel Q. Correction to DNA Compatible Multistep Synthesis and Applications to DNA Encoded Libraries. Bioconjug Chem 2016; 27:2580. [DOI: 10.1021/acs.bioconjchem.6b00185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Satz AL, Cai J, Chen Y, Goodnow R, Gruber F, Kowalczyk A, Petersen A, Naderi-Oboodi G, Orzechowski L, Strebel Q. DNA Compatible Multistep Synthesis and Applications to DNA Encoded Libraries. Bioconjug Chem 2015; 26:1623-32. [DOI: 10.1021/acs.bioconjchem.5b00239] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Jianping Cai
- Roche Innovation Center, Basel 4070, Switzerland
| | - Yi Chen
- Hoffmann-La Roche, Inc., Nutley, New Jersey 07110, United States
| | - Robert Goodnow
- Hoffmann-La Roche, Inc., Nutley, New Jersey 07110, United States
| | - Felix Gruber
- Roche Innovation Center, Basel 4070, Switzerland
| | | | - Ann Petersen
- Roche Innovation Center, Basel 4070, Switzerland
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Hicks A, Goodnow R, Cavallo G, Tannu SA, Ventre JD, Lavelle D, Lora JM, Satjawatcharaphong J, Brovarney M, Dabbagh K, Tare NS, Oh H, Lamb M, Sidduri A, Dominique R, Qiao Q, Lou JP, Gillespie P, Fotouhi N, Kowalczyk A, Kurylko G, Hamid R, Wright MB, Pamidimukkala A, Egan T, Gubler U, Hoffman AF, Wei X, Li YL, O'Neil J, Marcano R, Pozzani K, Molinaro T, Santiago J, Singer L, Hargaden M, Moore D, Catala AR, Chao LCF, Benson J, March T, Venkat R, Mancebo H, Renzetti LM. Effects of LTB4 receptor antagonism on pulmonary inflammation in rodents and non-human primates. Prostaglandins Other Lipid Mediat 2010; 92:33-43. [PMID: 20214997 DOI: 10.1016/j.prostaglandins.2010.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/24/2010] [Accepted: 02/27/2010] [Indexed: 01/15/2023]
Abstract
Asthma, chronic obstructive pulmonary disease (COPD) and acute lung injury/acute respiratory distress syndrome (ALI/ARDS) are characterized by neutrophilic inflammation and elevated levels of leukotriene B4 (LTB4). However, the exact role of LTB4 pathways in mediating pulmonary neutrophilia and the potential therapeutic application of LTB4 receptor antagonists in these diseases remains controversial. Here we show that a novel dual BLT1 and BLT2 receptor antagonist, RO5101576, potently inhibited LTB4-evoked calcium mobilization in HL-60 cells and chemotaxis of human neutrophils. RO5101576 significantly attenuated LTB4-evoked pulmonary eosinophilia in guinea pigs. In non-human primates, RO5101576 inhibited allergen and ozone-evoked pulmonary neutrophilia, with comparable efficacy to budesonide (allergic responses). RO5101576 had no effects on LPS-evoked neutrophilia in guinea pigs and cigarette smoke-evoked neutrophilia in mice and rats. In toxicology studies RO5101576 was well-tolerated. Theses studies show differential effects of LTB4 receptor antagonism on neutrophil responses in vivo and suggest RO5101576 may represent a potential new treatment for pulmonary neutrophilia in asthma.
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Affiliation(s)
- Alexandra Hicks
- Department of RNA Therapeutics, Roche, 340 Kingsland Street, Nutley, NJ 07110, USA.
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Hicks A, Monkarsh SP, Hoffman AF, Goodnow R. Leukotriene B4 receptor antagonists as therapeutics for inflammatory disease: preclinical and clinical developments. Expert Opin Investig Drugs 2008; 16:1909-20. [PMID: 18042000 DOI: 10.1517/13543784.16.12.1909] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Leukotriene B(4) (LTB(4)) is a lipid inflammatory mediator derived from membrane phospholipids by the sequential actions of cytosolic phospholipase A2 (PLA2), 5-lipoxygenase (5-LO) and leukotriene A(4) (LTA(4)) hydrolase. Several inflammatory diseases, including asthma, chronic obstructive pulmonary disease, arthritis and inflammatory bowel disease, have been associated with elevated levels of LTB(4). As a result, pharmacological strategies to modulate the synthesis of LTB(4) (inhibition of PLA2, 5-LO or LTA(4) hydrolase) or the effects of LTB(4) itself (antagonism of LTB(4) receptors) are being developed by several companies. Two G-protein-coupled receptors mediate the effects of LTB(4), namely BLT1 and BLT2. The pharmacology, expression and function of these two receptors were last reviewed by Tager and Luster in 2004. Since then, there has been an increased understanding of the function of these receptors, in particular for the lesser understood of the two receptors, BLT2. Furthermore, since last reviewed in 1996, there have been several clinical developments in the use of BLT receptor antagonists for inflammatory diseases. This review summarizes the latest preclinical and clinical developments in BLT antagonism for inflammatory diseases and discusses potential future developments.
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Affiliation(s)
- Alexandra Hicks
- Department of Inflammation Discovery, 340 Kingsland Street, Nutley, New Jersey, NJ 07110, USA.
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Wang Z, Li S, Ferguson S, Goodnow R, Ho CT. Validated reversed phase LC method for quantitative analysis of polymethoxyflavones in citrus peel extracts. J Sep Sci 2008; 31:30-7. [DOI: 10.1002/jssc.200700331] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hermann G, Annis M, Edwards P, Corrales M, Díaz L, Goodnow R. An Efficient Synthetic Route to Novel 3-Alkyl- and 3-Aryl-4-iodophenols. SYNTHESIS-STUTTGART 2008. [DOI: 10.1055/s-2007-1000860] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wang Z, Jonca M, Lambros T, Ferguson S, Goodnow R. Exploration of liquid and supercritical fluid chromatographic chiral separation and purification of Nutlin-3—A small molecule antagonist of MDM2. J Pharm Biomed Anal 2007; 45:720-9. [PMID: 17897804 DOI: 10.1016/j.jpba.2007.08.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 08/06/2007] [Accepted: 08/09/2007] [Indexed: 01/12/2023]
Abstract
Inhibition of the MDM2-p53 interaction can stabilize the p53 protein and offer a novel strategy for cancer therapy. The imidazoline compound (Nutlin-3) is a promising small molecule antagonist of the MDM2-p53 interaction. This compound was synthesized as a racemic mixture, and one enantiomer is 100-200-fold more active than the other enantiomer. In this study, various enantiomeric separation approaches were explored to resolve the Nutlin-3 enantiomers using chiral supercritical fluid chromatography (SFC) as well as chiral liquid chromatography (LC) under normal phase mode, reversed phase mode and polar organic phase mode. The chiral SFC method based on Chiralcel OD column showed superior separation in terms of selectivity and efficiency. Optimization of the chiral separation method enabled high throughput preparative scale purification. Ultimately, 5 g of racemic mixture were purified on Prep-SFC in 75 min with the recovery rate above 92%.
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Affiliation(s)
- Zhenyu Wang
- Discovery Chemistry, Hoffmann-La Roche Inc., Nutley, NJ 07110, USA.
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Li S, Lambros T, Wang Z, Goodnow R, Ho CT. Efficient and scalable method in isolation of polymethoxyflavones from orange peel extract by supercritical fluid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 846:291-7. [PMID: 17035106 DOI: 10.1016/j.jchromb.2006.09.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 08/30/2006] [Accepted: 09/08/2006] [Indexed: 11/26/2022]
Abstract
Polymethoxyflavones (PMFs) from citrus genus are of particular interest because of their broad spectrum of biological activities, such as anti-inflammatory, anti-carcinogenic, and anti-atherogenic properties. Recently, the exploration into the beneficial health properties of PMFs in citrus fruits has dramatically increased. However, the supply of pure PMFs in the in vivo study is a limiting factor due to the difficulties in large-scale isolation of the interested PMFs. Therefore, the development of an efficient and a scalable separation method of PMFs is necessary and significant. In this paper, we report a newly developed method for efficient and relatively large-scale isolation of four PMFs from sweet orange (Citrus sinensis) peel by employing supercritical chromatography (SFC): nobiletin, tangeretin, 3,5,6,7,8,3',4'-heptamethoxyflavone and 5,6,7,4'-tetramethoxyflavone.
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Affiliation(s)
- Shiming Li
- Department of Drug Discovery, Hoffmann-La Roche Inc., Nutley, NJ 07110, USA.
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Wang Z, Li S, Jonca M, Lambros T, Ferguson S, Goodnow R, Ho CT. Comparison of supercritical fluid chromatography and liquid chromatography for the separation of urinary metabolites of nobiletin with chiral and non-chiral stationary phases. Biomed Chromatogr 2006; 20:1206-15. [PMID: 16799930 DOI: 10.1002/bmc.686] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Nobiletin (NOB), a polymethoxylated flavone found in sweet orange (Citrus sinensis) peel, is currently recognized as a promising anti-inflammatory and anti-tumor agent. It is believed that, by undergoing metabolic biotransformation in vivo, nobiletin is demethylated by hepatic P450 enzymes, yielding multiple hydroxylated metabolites. However, it has not been possible to date to separate the two demethylated nobiletin metabolites, 3'-demethyl-NOB and 4'-demethyl-NOB (regio-isomers) on reversed-phase liquid chromatography (RPLC). Additionally, both display similar mass spectrometric fragmentation, resulting in difficulties to identify the dominant metabolite. A successful separation method was developed by utilizing supercritical fluid chromatography (SFC) with chiral stationary phase. The separation was also attempted with normal-phase liquid chromatography (NPLC) in both chiral and non-chiral modes. Chromatographic separation for the two nobiletin metabolites was superior by SFC than by LC, especially using chiral stationary phase. By comparing the SFC profile of the synthesized standards, the major nobiletin metabolite in mouse urine was identified as 4'-demethyl-NOB, with the concentration of 28.9 microg/mL.
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Affiliation(s)
- Zhenyu Wang
- Discovery Chemistry, Hoffmann-La Roche Inc. 340 Kingsland Street, Nutley, NJ 07110, USA.
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Roche O, Schneider P, Zuegge J, Guba W, Kansy M, Alanine A, Bleicher K, Danel F, Gutknecht EM, Rogers-Evans M, Neidhart W, Stalder H, Dillon M, Sjögren E, Fotouhi N, Gillespie P, Goodnow R, Harris W, Jones P, Taniguchi M, Tsujii S, von der Saal W, Zimmermann G, Schneider G. Development of a virtual screening method for identification of "frequent hitters" in compound libraries. J Med Chem 2002; 45:137-42. [PMID: 11754585 DOI: 10.1021/jm010934d] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A computer-based method was developed for rapid and automatic identification of potential "frequent hitters". These compounds show up as hits in many different biological assays covering a wide range of targets. A scoring scheme was elaborated from substructure analysis, multivariate linear and nonlinear statistical methods applied to several sets of one and two-dimensional molecular descriptors. The final model is based on a three-layered neural network, yielding a predictive Matthews correlation coefficient of 0.81. This system was able to correctly classify 90% of the test set molecules in a 10-times cross-validation study. The method was applied to database filtering, yielding between 8% (compilation of trade drugs) and 35% (Available Chemicals Directory) potential frequent hitters. This filter will be a valuable tool for the prioritization of compounds from large databases, for compound purchase and biological testing, and for building new virtual libraries.
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Abstract
Chromomycin A3 (CRA3) is a glycosylated antitumor antibiotic that binds as a dimer to the minor groove of DNA, with a Mg2+ cation (or another divalent cation with a radius less than 0.85 A) forming the center of the dimer. It has been shown that the chromose sugars are necessary for DNA binding [Kaziro & Kamiyama (1967) J. Biochem. (Tokyo) 62, 424-429; Kamiyama (1968) J. Biochem. (Tokyo) 63, 566-572], although the reason for this has not been addressed. We have investigated the role that the chromose sugars play in metal complexation in solution (methanol) by comparing the optical behavior of CRA3 and its aglycon, CRN, in the presence of various divalent metals (Mg2+, Ni2+, and Ca2+). The results show that CRA3 forms a dimeric complex [i.e., (CRA3)2M, where M is a metal ion] in the presence of 1 mol equiv of either Ni2+ or Mg2+ but a 1:1 complex in the presence of the much larger Ca2+. In contrast, CRN forms a 1:1 complex (CRN.M)+ with all three metals under identical conditions (1:1 mole ratio of drug to metal). Thus, for the smaller metal ions the sugars stabilize the 2:1 CRA3-metal complex in solution. NMR data on the 2:1 CRA3-Mg2+ complex show that the trisaccharide of one CRA3 molecule lies in close proximity to the chromophore of the other CRA3 molecule. This interaction, which is also present in the Mg(2+)-CRA3-DNA complex [Gao & Patel (1989) Biochemistry 28, 751-762], appears to be related to the stability of the dimer in solution.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D J Silva
- Department of Chemistry, Princeton University, New Jersey 08544
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Brundell P, Goodnow R, Kerry CJ, Nakanishi K, Sudan HL, Usherwood PN. Quisqualate-sensitive glutamate receptors of the locust Schistocerca gregaria are antagonised by intracellularly applied philanthotoxin and spermine. Neurosci Lett 1991; 131:196-200. [PMID: 1722296 DOI: 10.1016/0304-3940(91)90612-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of intracellularly and extracellularly applied synthetic analogues of delta-philanthotoxin (PhTX-433) and the polyamine spermine on the excitatory postsynaptic current (EPSC) of glutamatergic synapses and single channel currents gated by quisqualate-sensitive glutamate receptors (QUIS-R) on locust leg muscle have been compared. When applied extracellularly all 3 compounds reversibly antagonised the EPSC and the single channel currents. Antagonism was voltage independent, but use (agonist) dependent. Antagonism also occurred when they were injected into muscle fibres, but in this case it was not use dependent. It is proposed that spermine and the two toxins bind to the closed and open channel conformations of QUIS-R at a site near the intracellular opening of the channel gated by this receptor.
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Affiliation(s)
- P Brundell
- Department of Life Science, University of Nottingham, U.K
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Anis N, Sherby S, Goodnow R, Niwa M, Konno K, Kallimopoulos T, Bukownik R, Nakanishi K, Usherwood P, Eldefrawi A. Structure-activity relationships of philanthotoxin analogs and polyamines on N-methyl-D-aspartate and nicotinic acetylcholine receptors. J Pharmacol Exp Ther 1990; 254:764-73. [PMID: 2168484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The effects of varying the structure of philanthotoxin (PhTX) were investigated on binding of the channel blockers: [3H]perhydrohistrionicotoxin (H12-HTX) to the nicotinic acetylcholine receptor (nACh-R) of Torpedo electric organ and [3H]MK-801 [( 3H]-5-methyl-10,11-dihydro-5H-dibenzocyclo-hepten-5,10-imine maleate) to the N-methyl-D-aspartate receptor (NMDA-R) of rat brain cortex. The four moieties of PhTX (tyrosine, butyrate, spermine and the terminal amino group) were modified or conjugated resulting in 36 compounds. Although the potencies of the PhTX analogs on both receptors were higher with increasing lipophilicity and the polyamine chain length, there was considerable divergence between the two receptors' channels in the structural activity requirements for blockade by PhTX analogs. A major difference was the more critical role of the amine terminal for inhibition of the nACh-R than the NMDA-R, whereas the reverse might be true for the tyrosine moiety. The potency range of PhTX analogs on [3H]H12-HTX binding was 1070, but only 21 on [3H]MK-801 binding. Adding a lysine or arginine onto the spermine moiety increased the compound's potency on the nACh-R with little effect on the NMDA-R. Because spermine is a component of PhTX, the effects of five polyamines were also studied. Spermine and spermidine potentiated [3H]MK-801 binding, whereas putrescine, cadeverine and agmatine inhibited it. In presence of glutamate, higher concentrations of all polyamines inhibited [3H]MK-801 binding. On the nACh-R, spermine, spermidine and agmatine inhibited [125I]alpha-bungarotoxin and also [3H]H12-HTX binding in presence of carbamylcholine. The complex nature of PhTX interactions with the two receptors suggests that PhTX may bind to two sites: an external polyamine binding site and a channel binding site.
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Affiliation(s)
- N Anis
- Department of Pharmacology & Experimental Therapeutics, University of Maryland School of Medicine, Baltimore
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Brackley P, Goodnow R, Nakanishi K, Sudan HL, Usherwood PN. Spermine and philanthotoxin potentiate excitatory amino acid responses of Xenopus oocytes injected with rat and chick brain RNA. Neurosci Lett 1990; 114:51-6. [PMID: 1696366 DOI: 10.1016/0304-3940(90)90427-b] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effects of spermine and a synthetic analogue (PhTX-343) of the polyamine amide toxin, delta-philanthotoxin, on the responses of Xenopus oocytes to application of amino acids were examined using voltage clamp. The oocytes were injected with either total rat brain RNA or chick cerebrum, poly(A+)RNA. The responses to N-methyl-D-aspartate and L-kainate were potentiated by low concentrations (10(-11)-10(-7) M) of PhTX-343 and by 10(-5)-10(-4) M spermine. There was variability between oocytes in terms of their responsiveness to these compounds and recovery from their effects was slow and often incomplete. Prolonged or repeated applications of PhTX-343 and spermine eventually resulted in inhibition. Higher concentrations of these compounds always inhibited the responses to acidic amino acids. Low concentrations of PhTX-343 and spermine also potentiated the responses to nicotine and gamma-aminobutyric acid. These results are discussed in terms of the postulated polyamine binding site on the N-methyl-D-aspartate receptor.
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Affiliation(s)
- P Brackley
- Department of Zoology, University of Nottingham, U.K
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Bruce M, Bukownik R, Eldefrawi AT, Eldefrawi ME, Goodnow R, Kallimopoulos T, Konno K, Nakanishi K, Niwa M, Usherwood PN. Structure-activity relationships of analogues of the wasp toxin philanthotoxin: non-competitive antagonists of quisqualate receptors. Toxicon 1990; 28:1333-46. [PMID: 1965063 DOI: 10.1016/0041-0101(90)90098-r] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fifty-two analogues of the wasp toxin, philanthotoxin-433, have been synthesized and tested on a glutamatergic, nerve-muscle preparation from locust leg. Reduction in amplitude of the neurally-evoked muscle twitch was used to construct dose-inhibition relationships from which IC50S were estimated. The most active analogues were characterized by one or more of the following: increased hydrophobicity of aromatic and tyrosyl regions; an increased number of protonated groups in the polyamine region; a guanidinium instead of a spermine terminal amino moiety. The incorporation of a butyl side-group in the polyamine also enhanced potency. These results are explained on the basis of the known non-competitive antagonistic blockage by philanthotoxin-433 of the channel gated by postjunctional glutamate receptors when the channel is open.
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Affiliation(s)
- M Bruce
- Department of Zoology, School of Biological Sciences, University of Nottingham, U.K
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Durban E, Goodnow R, Grecz N. Changes in resistance to radiation and heat during sporulation and germination of Clostridium botulinum 33A. J Bacteriol 1970; 102:590-2. [PMID: 4911549 PMCID: PMC247591 DOI: 10.1128/jb.102.2.590-592.1970] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
During sporulation, Clostridium botulinum 33A developed resistance to ultraviolet and gamma rays about 2 hr prior to its development of heat resistance. During germination, loss of resistance to heat, ultraviolet radiation, and gamma radiation occurred essentially simultaneously.
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