1
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Investigating the effects of different natural molecules on the structure and oligomerization propensity of hen egg-white lysozyme. Int J Biol Macromol 2019; 134:189-201. [DOI: 10.1016/j.ijbiomac.2019.05.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/25/2019] [Accepted: 05/07/2019] [Indexed: 12/17/2022]
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2
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Xie Y, Dahlin JL, Oakley AJ, Casarotto MG, Board PG, Baell JB. Reviewing Hit Discovery Literature for Difficult Targets: Glutathione Transferase Omega-1 as an Example. J Med Chem 2018; 61:7448-7470. [PMID: 29652143 DOI: 10.1021/acs.jmedchem.8b00318] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Early stage drug discovery reporting on relatively new or difficult targets is often associated with insufficient hit triage. Literature reviews of such targets seldom delve into the detail required to critically analyze the associated screening hits reported. Here we take the enzyme glutathione transferase omega-1 (GSTO1-1) as an example of a relatively difficult target and review the associated literature involving small-molecule inhibitors. As part of this process we deliberately pay closer-than-usual attention to assay interference and hit quality aspects. We believe this Perspective will be a useful guide for future development of GSTO1-1 inhibitors, as well serving as a template for future review formats of new or difficult targets.
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Affiliation(s)
- Yiyue Xie
- Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , Victoria 3052 , Australia
| | - Jayme L Dahlin
- Department of Pathology , Brigham and Women's Hospital , Boston , Massachusetts 02135 , United States
| | - Aaron J Oakley
- School of Chemistry , University of Wollongong , Wollongong , NSW 2522 , Australia
| | - Marco G Casarotto
- John Curtin School of Medical Research , Australian National University , Canberra , ACT 2600 , Australia
| | - Philip G Board
- John Curtin School of Medical Research , Australian National University , Canberra , ACT 2600 , Australia
| | - Jonathan B Baell
- Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , Victoria 3052 , Australia.,School of Pharmaceutical Sciences , Nanjing Tech University , Nanjing , 211816 , People's Republic of China
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3
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Hilt S, Rojalin T, Viitala T, Koivuniemi A, Bunker A, Hogiu SW, Kálai T, Hideg K, Yliperttula M, Voss JC. Oligomerization Alters Binding Affinity Between Amyloid Beta and a Modulator of Peptide Aggregation. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:23974-23987. [PMID: 30214656 PMCID: PMC6130836 DOI: 10.1021/acs.jpcc.7b06164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The soluble oligomeric form of the amyloid beta (Aβ) peptide is the major causative agent in the molecular pathogenesis of Alzheimer's disease (AD). We have previously developed a pyrroline-nitroxyl fluorene compound (SLF) that blocks the toxicity of Aβ. Here we introduce the multi-parametric surface plasmon resonance (MP-SPR) approach to quantify SLF binding and effect on the self-association of the peptide via a label-free, real-time approach. Kinetic analysis of SLF binding to Aβ and measurements of layer thickness alterations inform on the mechanism underlying the ability of SLF to inhibit Aβ toxicity and its progression towards larger oligomeric assemblies. Depending on the oligomeric state of Aβ, distinct binding affinities for SLF are revealed. The Aβ monomer and dimer uniquely possess sub-nanomolar affinity for SLF via a non-specific mode of binding. SLF binding is weaker in oligomeric Aβ, which displays an affinity for SLF on the order of 100 μM. To complement these experiments we carried out molecular docking and molecular dynamics simulations to explore how SLF interacts with the Aβ peptide. The MP-SPR results together with in silico modeling provide affinity data for the SLF-Aβ interaction and allow us to develop a new general method for examining protein aggregation.
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Affiliation(s)
- Silvia Hilt
- Department of Biochemistry & Molecular Medicine, University of California, Davis, CA 95616, USA
| | - Tatu Rojalin
- Department of Pathology and Laboratory Medicine, and Center for Biophotonics, University of California Davis, USA
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Finland
| | - Tapani Viitala
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Finland
| | - Artturi Koivuniemi
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Finland
| | - Alex Bunker
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Finland
| | - Sebastian Wachsmann Hogiu
- Department of Pathology and Laboratory Medicine, and Center for Biophotonics, University of California Davis, USA
- Intellectual Ventures/Global Good, Bellevue, WA, USA
| | - Tamás Kálai
- Institute of Organic and Medicinal Chemistry, University of Pécs, H 7624 Pécs, Szigeti st. 12. Pécs, Hungary
| | - Kálmán Hideg
- Institute of Organic and Medicinal Chemistry, University of Pécs, H 7624 Pécs, Szigeti st. 12. Pécs, Hungary
| | - Marjo Yliperttula
- Centre for Drug Research, Division of Pharmaceutical Biosciences, University of Helsinki, Finland
- Department of Pharmaceutical Sciences, University of Padova, Italy
| | - John C. Voss
- Department of Biochemistry & Molecular Medicine, University of California, Davis, CA 95616, USA
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4
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Pihlasalo S, Deguchi T, Virtamo M, Jacobino J, Chary K, López-Picón FR, Brunhofer-Bolzer G, Huttunen R, Fallarero A, Vuorela P, Härmä H. Luminometric Nanoparticle-Based Assay for High Sensitivity Detection of β-Amyloid Aggregation. Anal Chem 2017; 89:2398-2404. [PMID: 28219250 DOI: 10.1021/acs.analchem.6b04266] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A nanoparticle-based assay utilizing time-resolved luminescence resonance energy transfer (TR-LRET) was developed for the detection of β-amyloid aggregation. The assay is based on the competitive adsorption of the sample and the acceptor-labeled protein to donor europium(III) polystyrene nanoparticles. The performance of the assay was demonstrated by following the fibrillization of β-amyloid peptide 1-42 (Aβ42) as a function of time and by comparing to the reference methods atomic force microscopy (AFM) and thioflavin T (ThT) assay. The fibrillization leads to reduced adsorption of Aβ42 to the nanoparticles increasing the TR-LRET signal. The investigated methods detected fibril formation with equal sensitivities. Eight potential fibrillization inhibitor compounds reported in the literature were tested and the results obtained with each method were compared. It was shown with AFM imaging that the inhibition of fibril formation was not complete with any of the compounds. The developed TR-LRET nanoparticle assay gave corresponding results with the AFM imaging. However, the ThT assay led to contradictory results, as low fluorescence signal was measured in the presence of all tested compounds suggesting inhibition of fibrillization. Our results suggest that the developed TR-LRET nanoparticle assay can be exploited for screening of potential β-amyloid aggregation inhibitors, whereas some of the tested compounds may be measured as false positive inhibitors with the much-utilized ThT assay.
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Affiliation(s)
- Sari Pihlasalo
- Laboratory of Materials Chemistry and Chemical Analysis, Department of Chemistry, University of Turku , Vatselankatu 2, FI-20500 Turku, Finland.,Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Takahiro Deguchi
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Maria Virtamo
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Jenna Jacobino
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Karthik Chary
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Francisco R López-Picón
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku , Itäinen Pitkäkatu 4B, FI-20520 Turku, Finland
| | - Gerda Brunhofer-Bolzer
- Department of Medicinal Chemistry, University of Vienna , Althanstrasse 14, A-1090 Vienna, Austria
| | - Roope Huttunen
- Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
| | - Adyary Fallarero
- Pharmaceutical Design and Discovery Group (PharmDD), Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , Viikinkaari 5E, FI-00014 Helsinki, Finland
| | - Pia Vuorela
- Pharmaceutical Design and Discovery Group (PharmDD), Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , Viikinkaari 5E, FI-00014 Helsinki, Finland
| | - Harri Härmä
- Laboratory of Materials Chemistry and Chemical Analysis, Department of Chemistry, University of Turku , Vatselankatu 2, FI-20500 Turku, Finland.,Laboratory of Biophysics, Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku , Tykistökatu 6A, FI-20520 Turku, Finland
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5
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Jameson LP, Smith NW, Dzyuba SV. Dye-binding assays for evaluation of the effects of small molecule inhibitors on amyloid (aβ) self-assembly. ACS Chem Neurosci 2012; 3:807-19. [PMID: 23173064 DOI: 10.1021/cn300076x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 08/06/2012] [Indexed: 01/07/2023] Open
Abstract
Dye-binding assays, such as those utilizing Congo red and thioflavin T, are among the most widely used tools to probe the aggregation of amyloidogenic biomolecules and for the evaluation of small molecule inhibitors of amyloid aggregation and fibrillization. A number of recent reports have indicated that these dye-binding assays could be prone to false positive effects when assessing inhibitors' potential toward Aβ peptides, species involved in Alzheimer's disease. Specifically, this review focuses on the application of thioflavin T for determining the efficiency of small molecule inhibitors of Aβ aggregation and addresses potential reasons that might be associated with the false positive effects in an effort to increase reliability of dye-binding assays.
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Affiliation(s)
- Laramie P. Jameson
- Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129, United States
| | - Nicholas W. Smith
- Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129, United States
| | - Sergei V. Dzyuba
- Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129, United States
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6
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Zhao T, Zeng Y, Kermode AR. A plant cell-based system that predicts aβ42 misfolding: potential as a drug discovery tool for Alzheimer's disease. Mol Genet Metab 2012; 107:571-9. [PMID: 22944366 DOI: 10.1016/j.ymgme.2012.08.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 08/09/2012] [Accepted: 08/09/2012] [Indexed: 01/02/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid β (Aβ) peptides and the failure of mechanisms to clear toxic aggregates. The Aβ42 peptide is considered to be a causative factor that underlies the pathophysiology of AD, in part due to its propensity for misfolding and aggregation; the small oligomers that result represent toxic species. Thus agents that prevent Aβ42 misfolding/aggregation or, alternatively improve Aβ42 oligomer clearance, may have significant therapeutic value. We have developed the basis for a drug screening system based on transgenic plant cells that express Aβ42 fusion proteins to serve as the reliable indicators of the general conformational status of Aβ42. Within cells of transgenic tobacco and Nicotiana benthamiana, misfolding of Aβ42 causes the misfolding of a GFP fusion partner, and consequently there is a loss of fluorescence associated with the native GFP protein. In a similar fusion consisting of Aβ42 linked to hygromycin phosphotransferase II (Hpt II), a hygromycin-resistance marker, misfolding of Aβ42 leads to a misfolded Hpt II, and consequently the transgenic cells are unable to grow on media containing hygromycin. Importantly, substitution of the 'aggregation-prone' Aβ42 with a missense mutant of Aβ42 (F19S/L34F) that is not prone to misfolding/aggregation, 'rescues' both fusion partners. Several 'positive control' chemicals that represent inhibitors of Aβ42 aggregation, including curcumin, epigallocatechin-3-gallate (EGCG), and resveratrol show efficacy in preventing the Aβ42-fusion proteins from misfolding/aggregating in the transgenic plant cells. We discuss the potential of the two fusion protein systems to serve as the basis for an inexpensive, selective, and efficient screening system in which a plant cell can fluoresce or survive only in the presence of drug candidates that are able to prevent Aβ42 misfolding/aggregation.
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Affiliation(s)
- Tiehan Zhao
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr, Burnaby, BC, Canada V5A 1S6.
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7
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Jameson LP, Dzyuba SV. Spectroscopic studies on tetracycline in room-temperature ionic liquids. JOURNAL OF NATURAL PRODUCTS 2011; 74:310-313. [PMID: 21268600 DOI: 10.1021/np100743m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Circular dichroism and steady-state fluorescence of tetracycline (1) were investigated in a series of 1-butyl-3-methylimidazolium room-temperature ionic liquids. The identity of the anion of the ionic liquids was found to modulate the conformation as well as the emission intensity of tetracycline over a wide range.
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Affiliation(s)
- Laramie P Jameson
- Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129, United States
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8
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Ouberai M, Dolphin GT, Dumy P, Garcia J. Amyloidogenesis highlighted by designed peptides forming supramolecular self-assemblies. Chem Sci 2011. [DOI: 10.1039/c1sc00016k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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9
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Ouberai M, Brannstrom K, Vestling M, Olofsson A, Dumy P, Chierici S, Garcia J. Clicked tacrine conjugates as acetylcholinesterase and β-amyloid directed compounds. Org Biomol Chem 2011; 9:1140-7. [DOI: 10.1039/c0ob00393j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Maheshwari M, Roberts JK, DeSutter B, Duong K, Tingling J, Fawver JN, Schall HE, Kahle M, Murray IV. Hydralazine modifies Aβ fibril formation and prevents modification by lipids in vitro. Biochemistry 2010; 49:10371-80. [PMID: 21058733 PMCID: PMC3033120 DOI: 10.1021/bi101249p] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipid oxidative damage and amyloid β (Aβ) misfolding contribute to Alzheimer's disease (AD) pathology. Thus, the prevention of oxidative damage and Aβ misfolding are attractive targets for drug discovery. At present, no AD drugs approved by the Food and Drug Administration (FDA) prevent or halt disease progression. Hydralazine, a smooth muscle relaxant, is a potential drug candidate for AD drug therapy as it reduces Aβ production and prevents oxidative damage via its antioxidant hydrazide group. We evaluated the efficacy of hydralazine, and related hydrazides, in reducing (1) Aβ misfolding and (2) Aβ protein modification by the reactive lipid 4-hydroxy-2-nonenal (HNE) using transmission electron microscopy and Western blotting. While hydralazine did not prevent Aβ aggregation as measured using the protease protection assay, there were more oligomeric species observed by electron microscopy. Hydralazine prevented lipid modification of Aβ, and Aβ was used as a proxy for classes of proteins which either misfold or are modified by HNE. All of the other hydrazides prevented lipid modification of Aβ and also did not prevent Aβ aggregation. Surprisingly, a few of the compounds, carbazochrome and niclosamide, appeared to augment Aβ formation. Thus, hydrazides reduced lipid oxidative damage, and hydralazine additionally reduced Aβ misfolding. While hydralazine would require specific chemical modifications for use as an AD therapeutic itself (to improve blood brain barrier permeability, reduce vasoactive side effects, and optimization for amyloid inhibition), this study suggests its potential merit for further AD drug development.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Ian V.J. Murray
- To whom correspondence should be addressed: Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, 142E Reynolds Medical Building, College Station Texas. 77843-1114. Telephone: (979) 458-4355. Fax: 979 845-0790.
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11
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Chen J, Armstrong AH, Koehler AN, Hecht MH. Small molecule microarrays enable the discovery of compounds that bind the Alzheimer's Aβ peptide and reduce its cytotoxicity. J Am Chem Soc 2010; 132:17015-22. [PMID: 21062056 DOI: 10.1021/ja107552s] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The amyloid-β (Aβ) aggregation pathway is a key target in efforts to discover therapeutics that prevent or delay the onset of Alzheimer's disease. Efforts at rational drug design, however, are hampered by uncertainties about the precise nature of the toxic aggregate. In contrast, high-throughput screening of compound libraries does not require a detailed understanding of the structure of the toxic species, and can provide an unbiased method for the discovery of small molecules that may lead to effective therapeutics. Here, we show that small molecule microarrays (SMMs) represent a particularly promising tool for identifying compounds that bind the Aβ peptide. Microarray slides with thousands of compounds immobilized on their surface were screened for binding to fluorescently labeled Aβ. Seventy-nine compounds were identified by the SMM screen, and then assayed for their ability to inhibit the Aβ-induced killing of PC12 cells. Further experiments focused on exploring the mechanism of rescue for one of these compounds: Electron microscopy and Congo red binding showed that the compound enhances fibril formation, and suggest that it may rescue cells by accelerating Aβ aggregation past an early toxic oligomer. These findings demonstrate that the SMM screen for binding to Aβ is effective at identifying compounds that reduce Aβ toxicity, and can reveal potential therapeutic leads without the biases inherent in methods that focus on inhibitors of aggregation.
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Affiliation(s)
- Jermont Chen
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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12
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Zovo K, Helk E, Karafin A, Tõugu V, Palumaa P. Label-Free High-Throughput Screening Assay for Inhibitors of Alzheimer’s Amyloid-β Peptide Aggregation Based on MALDI MS. Anal Chem 2010; 82:8558-65. [DOI: 10.1021/ac101583q] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Kairit Zovo
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Eneken Helk
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Ann Karafin
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Vello Tõugu
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Peep Palumaa
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
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13
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Ouberai M, Dumy P, Chierici S, Garcia J. Synthesis and Biological Evaluation of Clicked Curcumin and Clicked KLVFFA Conjugates as Inhibitors of β-Amyloid Fibril Formation. Bioconjug Chem 2009; 20:2123-32. [DOI: 10.1021/bc900281b] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Myriam Ouberai
- Département de Chimie Moléculaire (DCM), UMR 5250, ICMG-FR, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
| | - Pascal Dumy
- Département de Chimie Moléculaire (DCM), UMR 5250, ICMG-FR, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
| | - Sabine Chierici
- Département de Chimie Moléculaire (DCM), UMR 5250, ICMG-FR, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
| | - Julian Garcia
- Département de Chimie Moléculaire (DCM), UMR 5250, ICMG-FR, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
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14
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Yazdanparast R, Shaykhalishahi H. Protective effect of a triazine-derivative (AA3E2) on beta-amyloid-induced damages in SK-N-MC cells. Toxicol In Vitro 2009; 23:1277-83. [PMID: 19631265 DOI: 10.1016/j.tiv.2009.07.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 06/24/2009] [Accepted: 07/17/2009] [Indexed: 01/29/2023]
Abstract
The role of beta-amyloid (A beta) in the pathogenesis of Alzheimer's disease (AD) is frequently reported in the literature. Though the exact mode of action is not known, it is suggested that A beta induces cell death through induction of oxidative stress possibly through hydrogen peroxide generation. In that case, antioxidants should be capable of attenuating the A beta-induced cytotoxicities. In that regard, we evaluated the effect(s) of a triazine-derivative, AA3E2, with established antioxidant activity. Pretreatment of SK-N-MC neuroblastoma cells with AA3E2, followed by exposure to A beta(1-42) showed 28.3% higher viability relative to the control cells which has not been treated with AA3E2. In addition, AA3E2 inhibited caspase-3 activation caused by A beta(1-42) and it attenuated A beta(1-42)-induced intracellular ROS (reactive oxygen species) accumulation. The lower level of intracellular free radicals was further confirmed by higher and lower activities of intracellular catalase and superoxide dismutase, respectively. These observations, parallel to the literature data, reconfirm the oxidative stress disrupting role of A beta(1-42) peptide. Thus, sequestration of this role by potential antioxidants such as AA3E2 might happen to be a suitable strategy for future treatments of AD.
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Affiliation(s)
- Razieh Yazdanparast
- Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran.
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15
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Dolphin GT, Renaudet O, Ouberai M, Dumy P, Garcia J, Reymond JL. Phenolic Oxime Oligomers Inhibit Alzheimer's Amyloid Fibril Formation and Disaggregate Fibrils In Vitro. Chembiochem 2009; 10:1325-9. [DOI: 10.1002/cbic.200900044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Chopra N, Gan W, Schreiber H, Kurutz JW, Meredith SC. Versatile cyclic templates for assembly of axially oriented ligands. Bioconjug Chem 2009; 20:231-40. [PMID: 19159293 DOI: 10.1021/bc800312x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this paper, we describe two novel types of planar cyclic peptide templates for the facile addition of ligands that extend axially from the plane of the template ring. The first uses beta-amino acids of alternating D- and L-chirality, since the insertion of the additional methylene group in the peptide backbone was predicted and subsequently shown by NMR and molecular modeling, to reorient ligands attached to amino acid side chain axially with respect to the template ring. A second contains alternating D- and L-amino acids with an achiral Gly residue interposed between each chiral amino acid. The inserted Gly residues also tend to reorient side chains axially rather than radially, as was demonstrated by NMR and molecular modeling. The axial orientation of attached ligands is intended to foster or allow interactions among attached ligands in situations in which this is desired. Two such situations that we consider are (1) development of immunological reagents with avidity effects and (2) modeling of oligomers in fibril-forming peptides. Toward the first of these goals, we demonstrated that these templates are suitable for attaching macromolecules, by incorporating two types of protein, neutravidin and trypsinogen. Toward the second goal, we demonstrate the attachment of two different fibril-forming peptides to the template. The templates described herein thus have many of the desirable traits of such molecules, i.e., (1) multivalency for the attachment of multiple ligands, (2) suitable chemical functions for facile attachment of ligands, (3) versatility as to the number and spacing of ligand attachment sites, (4) sufficient rigidity so that the attached ligands can be similarly oriented with respect to the template, and (5) sufficient flexibility to allow even large ligands, such as proteins, to attach and interact.
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Affiliation(s)
- Neeraj Chopra
- Department of Pathology, The University of Chicago, Chicago, Illinois 60637, USA
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17
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Dolphin GT, Chierici S, Ouberai M, Dumy P, Garcia J. A multimeric quinacrine conjugate as a potential inhibitor of Alzheimer's beta-amyloid fibril formation. Chembiochem 2008; 9:952-63. [PMID: 18330854 DOI: 10.1002/cbic.200700602] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Amyloid formation and accumulation of the amyloid beta-peptide (Abeta) in the brain is associated with Alzheimer's disease (AD) pathogenesis. Therefore, among the therapeutic approaches in development to fight the disease, the direct inhibition of the Abeta self-assembly process is currently widely investigated and is one of the most promising approaches. In this study we investigated the potential of a multimeric display of quinacrine derivatives, as compared to the monomer quinacrine, as a design principal for a novel class of inhibitors against Abeta fibril formation. The presented multimeric conjugate exhibits a cluster of four quinacrine derivatives on a rigid cyclopeptidic scaffold. Herein is reported the synthesis of the conjugate, together with the in vitro inhibitory evaluation of Abeta(1-40) fibrils using the thioflavin T fluorescence assay, and imaging with atomic force microscopy. Our data show that the multimeric compound inhibits Abeta(1-40) fibril formation with an IC(50) value of 20+/-10 microM, which contrasts with the nonactive monomeric analogue. This work suggests that assembling multiple copies of acridine moieties to a central scaffold, for multiple interactions, is a promising strategy for the engineering of inhibitors against Abeta fibril formation.
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Affiliation(s)
- Gunnar T Dolphin
- Département de Chimie Moléculaire, UMR 5250, ICMG FR-2607, CNRS, Université Joseph Fourier, B.P. 53, 38041 Grenoble Cedex 9, France
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