1
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Patel EN, Turner LD, Hixon MS, Janda KD. Identification of Slow-Binding Inhibitors of the BoNT/A Protease. ACS Med Chem Lett 2022; 13:742-747. [PMID: 35450355 PMCID: PMC9014515 DOI: 10.1021/acsmedchemlett.2c00028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/04/2022] [Indexed: 12/20/2022] Open
Abstract
Botulinum neurotoxin A (BoNT/A) is a lethal toxin, which causes botulism, and is categorized as a bioterrorism threat, which causes flaccid paralysis and death. Botulinum A neurotoxicity is governed through its light chain (LC), a zinc metalloprotease. Pharmacological investigations aimed at negating BoNT/A's LC have typically looked to inhibitors that have been shown to inhibit the light chain's activity by reversible zinc chelation within its active site. This report outlines the first examples of nonpeptidic inhibitors of the BoNT/A LC that possess slow-binding kinetics, a needed logic to counteract the longevity of BoNT/A. Cyclopropane, alkyl, and alkenyl derivatives of 2,4-dichlorocinamic hydroxamic acid (DCHA) were shown to possess both one-step and two-step slow-binding kinetics. Structure-kinetic relationships (SKRs) were observed and were rationalized with the aid of docking models that predicted improved interactions with residues within a hydrophobic cleft adjacent to the active site.
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Affiliation(s)
- Ealin N. Patel
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Lewis D. Turner
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
- Biosplice Therapeutics, 9360 Towne Centre Drive, San Diego, California 92121, United States
| | - Mark S. Hixon
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kim D. Janda
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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2
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Brown RW, Abdel-Megeed AM, Keller PA, Jones AJ, Sykes ML, Kaiser M, Baell JB, Avery VM, Hyland CJT. Investigation of thiazolyl-benzothiophenamides as potential agents for African sleeping sickness. RSC Med Chem 2020; 11:1413-1422. [PMID: 34095848 PMCID: PMC8126881 DOI: 10.1039/d0md00277a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/10/2020] [Indexed: 11/21/2022] Open
Abstract
African sleeping sickness is a potentially fatal neglected disease affecting sub-Saharan Africa. High-throughput screening identified the thiazolyl-benzothiophenamide 1 to be active against the causative parasite, Trypanosoma brucei. This work establishes structure-activity relationships of 1, guiding the design of second generation derivatives. After screening against the clinically relevant species T. b. rhodesiense, the derivative 16 was identified as a suitable candidate for further investigation.
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Affiliation(s)
- Ronald W Brown
- School of Chemistry and Molecular Bioscience, and Molecular Horizons Research Institute, University of Wollongong Wollongong 2522 NSW Australia
| | - Ashraf M Abdel-Megeed
- School of Chemistry and Molecular Bioscience, and Molecular Horizons Research Institute, University of Wollongong Wollongong 2522 NSW Australia
| | - Paul A Keller
- School of Chemistry and Molecular Bioscience, and Molecular Horizons Research Institute, University of Wollongong Wollongong 2522 NSW Australia
| | - Amy J Jones
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University Brisbane Innovation Park Nathan 4111 Australia
| | - Melissa L Sykes
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University Brisbane Innovation Park Nathan 4111 Australia
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute Basel 4051 Switzerland
- University of Basel 4003 Basel Switzerland
| | - Jonathan B Baell
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University Parkville 3052 Australia
| | - Vicky M Avery
- Discovery Biology, Griffith Institute for Drug Discovery, Griffith University Brisbane Innovation Park Nathan 4111 Australia
| | - Christopher J T Hyland
- School of Chemistry and Molecular Bioscience, and Molecular Horizons Research Institute, University of Wollongong Wollongong 2522 NSW Australia
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3
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Natural Compounds and Their Analogues as Potent Antidotes against the Most Poisonous Bacterial Toxin. Appl Environ Microbiol 2018; 84:AEM.01280-18. [PMID: 30389764 DOI: 10.1128/aem.01280-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/28/2018] [Indexed: 01/30/2023] Open
Abstract
Botulinum neurotoxins (BoNTs), the most poisonous proteins known to humankind, are a family of seven (serotype A to G) immunologically distinct proteins synthesized primarily by different strains of the anaerobic bacterium Clostridium botulinum Being the causative agents of botulism, the toxins block neurotransmitter release by specifically cleaving one of the three soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins, thereby inducing flaccid paralysis. The development of countermeasures and therapeutics against BoNTs is a high-priority research area for public health because of their extreme toxicity and potential for use as biowarfare agents. Extensive research has focused on designing antagonists that block the catalytic activity of BoNTs. In this study, we screened 300 small natural compounds and their analogues extracted from Indian plants for their activity against BoNT serotype A (BoNT/A) as well as its light chain (LCA) using biochemical and cellular assays. One natural compound, a nitrophenyl psoralen (NPP), was identified to be a specific inhibitor of LCA with an in vitro 50% inhibitory concentration (IC50) value of 4.74 ± 0.03 µM. NPP was able to rescue endogenous synaptosome-associated protein 25 (SNAP-25) from cleavage by BoNT/A in human neuroblastoma cells with an IC50 of 12.2 ± 1.7 µM, as well as to prolong the time to the blocking of neutrally elicited twitch tensions in isolated mouse phrenic nerve-hemidiaphragm preparations.IMPORTANCE The long-lasting endopeptidase activity of BoNT is a critical biological activity inside the nerve cell, as it prompts proteolysis of the SNARE proteins, involved in the exocytosis of the neurotransmitter acetylcholine. Thus, the BoNT endopeptidase activity is an appropriate clinical target for designing new small-molecule antidotes against BoNT with the potential to reverse the paralysis syndrome of botulism. In principle, small-molecule inhibitors (SMIs) can gain entry into BoNT-intoxicated cells if they have a suitable octanol-water partition coefficient (log P) value and other favorable characteristics (P. Leeson, Nature 481:455-456, 2012, https://doi.org/10.1038/481455a). Several efforts have been made in the past to develop SMIs, but inhibitors effective under in vitro conditions have not in general been effective in vivo or in cellular models (L. M. Eubanks, M. S. Hixon, W. Jin, S. Hong, et al., Proc Natl Acad Sci U S A 104:2602-2607, 2007, https://doi.org/10.1073/pnas.0611213104). The difference between the in vitro and cellular efficacy presumably results from difficulties experienced by the compounds in crossing the cell membrane, in conjunction with poor bioavailability and high cytotoxicity. The screened nitrophenyl psoralen (NPP) effectively antagonized BoNT/A in both in vitro and ex vivo assays. Importantly, NPP inhibited the BoNT/A light chain but not other general zinc endopeptidases, such as thermolysin, suggesting high selectivity for its target. Small-molecule (nonpeptidic) inhibitors have better oral bioavailability, better stability, and better tissue and cell permeation than antitoxins or peptide inhibitors.
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4
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Affiliation(s)
- Megan Garland
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Sebastian Loscher
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Matthew Bogyo
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
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5
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Antiproliferative activity of amino substituted benzo[b]thieno[2,3-b]pyrido[1,2-a]benzimidazoles explored by 2D and 3D cell culture system. Eur J Med Chem 2016; 125:722-735. [PMID: 27721156 DOI: 10.1016/j.ejmech.2016.09.084] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/09/2016] [Accepted: 09/25/2016] [Indexed: 11/21/2022]
Abstract
Benzimidazo[1,2-a]quinolines and benzo[b]thieno[2,3-b]pyrido[1,2-a]benzimidazoles with amino chains on the different positions have been evaluated by 2D and 3D assays on the human breast cancer cells. Pentacyclic derivatives were synthesized by microwave assisted amination to study the influence of the thiophene substructure on antitumor activity in comparison to tetracyclic analogues. The results obtained from 2D assay reveals that the antitumor activity is strongly dependent on the nature and position of amino chains. Tetracyclic derivatives displayed selective activity on SK-BR-3 with the 2-amino substituted derivatives as the most active ones while pentacyclic derivatives 6-16 and 21-25 showed more pronounced activity on T-47D. The evaluation of antitumor activity in the 3D assay pointed out that some of the tetracyclic and pentacyclic amino substituted derivatives showed selective activity on the MDA-MB-231 cell line. Influence of physico-chemical properties of the compounds on antiproliferative activity have been investigated by multivariate statistical methods. As a measure of lipophilicity, experimental Chrom LogD values have been determined and number of structural parameters have been calculated for investigated compounds. Main factors contributing to the antiproliferative effect for both 2D and 3D cell cultures are found to be basicity, lipophilicity, molecular weight and number of H-bond donors.
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6
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Bompiani KM, Caglič D, Krutein MC, Benoni G, Hrones M, Lairson LL, Bian H, Smith GR, Dickerson TJ. High-Throughput Screening Uncovers Novel Botulinum Neurotoxin Inhibitor Chemotypes. ACS COMBINATORIAL SCIENCE 2016; 18:461-74. [PMID: 27314875 DOI: 10.1021/acscombsci.6b00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Botulism is caused by potent and specific bacterial neurotoxins that infect host neurons and block neurotransmitter release. Treatment for botulism is limited to administration of an antitoxin within a short time window, before the toxin enters neurons. Alternatively, current botulism drug development targets the toxin light chain, which is a zinc-dependent metalloprotease that is delivered into neurons and mediates long-term pathology. Several groups have identified inhibitory small molecules, peptides, or aptamers, although no molecule has advanced to the clinic due to a lack of efficacy in advanced models. Here we used a homogeneous high-throughput enzyme assay to screen three libraries of drug-like small molecules for new chemotypes that modulate recombinant botulinum neurotoxin light chain activity. High-throughput screening of 97088 compounds identified numerous small molecules that activate or inhibit metalloprotease activity. We describe four major classes of inhibitory compounds identified, detail their structure-activity relationships, and assess their relative inhibitory potency. A previously unreported chemotype in any context of enzyme inhibition is described with potent submicromolar inhibition (Ki = 200-300 nM). Additional detailed kinetic analyses and cellular cytotoxicity assays indicate the best compound from this series is a competitive inhibitor with cytotoxicity values around 4-5 μM. Given the potency and drug-like character of these lead compounds, further studies, including cellular activity assays and DMPK analysis, are justified.
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Affiliation(s)
- Kristin M. Bompiani
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Dejan Caglič
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Michelle C. Krutein
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Galit Benoni
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Morgan Hrones
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Luke L. Lairson
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Haiyan Bian
- Fox Chase Chemical Diversity Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Garry R. Smith
- Fox Chase Chemical Diversity Center, 3805 Old Easton Road, Doylestown, Pennsylvania 18902, United States
| | - Tobin J. Dickerson
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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7
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Kiris E, Burnett JC, Nuss JE, Wanner LM, Peyser BD, Du HT, Gomba GY, Kota KP, Panchal RG, Gussio R, Kane CD, Tessarollo L, Bavari S. SRC family kinase inhibitors antagonize the toxicity of multiple serotypes of botulinum neurotoxin in human embryonic stem cell-derived motor neurons. Neurotox Res 2015; 27:384-98. [PMID: 25782580 PMCID: PMC4455898 DOI: 10.1007/s12640-015-9526-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/05/2015] [Indexed: 02/07/2023]
Abstract
Botulinum neurotoxins (BoNTs), the causative agents of botulism, are potent inhibitors of neurotransmitter release from motor neurons. There are currently no drugs to treat BoNT intoxication after the onset of the disease symptoms. In this study, we explored how modulation of key host pathways affects the process of BoNT intoxication in human motor neurons, focusing on Src family kinase (SFK) signaling. Motor neurons derived from human embryonic stem (hES) cells were treated with a panel of SFK inhibitors and intoxicated with BoNT serotypes A, B, or E (which are responsible for >95 % of human botulism cases). Subsequently, it was found that bosutinib, dasatinib, KX2-391, PP1, PP2, Src inhibitor-1, and SU6656 significantly antagonized all three of the serotypes. Furthermore, the data indicated that the treatment of hES-derived motor neurons with multiple SFK inhibitors increased the antagonistic effect synergistically. Mechanistically, the small molecules appear to inhibit BoNTs by targeting host pathways necessary for intoxication and not by directly inhibiting the toxins' proteolytic activity. Importantly, the identified inhibitors are all well-studied with some in clinical trials while others are FDA-approved drugs. Overall, this study emphasizes the importance of targeting host neuronal pathways, rather than the toxin's enzymatic components, to antagonize multiple BoNT serotypes in motor neurons.
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Affiliation(s)
- Erkan Kiris
- Geneva Foundation, Tacoma, WA, USA
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
- Neural Development Section, Mouse Cancer Genetics Program, Center for Cancer Research, NCI, Frederick, MD 21702, USA
| | - James C. Burnett
- Leidos Biomedical Research, Inc., Computational Drug Development Group (CDDG), NCI, Frederick, MD 21702, USA
- CDDG, Developmental Therapeutics Program, NCI, Frederick, MD 21702, USA
| | - Jonathan E. Nuss
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Laura M. Wanner
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Brian D. Peyser
- CDDG, Developmental Therapeutics Program, NCI, Frederick, MD 21702, USA
| | - Hao T. Du
- Neural Development Section, Mouse Cancer Genetics Program, Center for Cancer Research, NCI, Frederick, MD 21702, USA
| | - Glenn Y. Gomba
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Krishna P. Kota
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Rekha G. Panchal
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
| | - Rick Gussio
- CDDG, Developmental Therapeutics Program, NCI, Frederick, MD 21702, USA
| | - Christopher D. Kane
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
- Henry M. Jackson Foundation, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute (BHSAI), Telemedicine and Advanced Technology Research Center (TATRC), US Army Medical Research and Materiel Command (USAMRMC), Frederick, MD 2170, USA
| | - Lino Tessarollo
- Neural Development Section, Mouse Cancer Genetics Program, Center for Cancer Research, NCI, Frederick, MD 21702, USA
| | - Sina Bavari
- Department of Molecular and Translational Sciences, US Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Fort Detrick, Frederick, MD 21702, USA
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8
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Farrow B, Wong M, Malette J, Lai B, Deyle KM, Das S, Nag A, Agnew HD, Heath JR. Epitope Targeting of Tertiary Protein Structure Enables Target-Guided Synthesis of a Potent In-Cell Inhibitor of Botulinum Neurotoxin. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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9
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Farrow B, Wong M, Malette J, Lai B, Deyle KM, Das S, Nag A, Agnew HD, Heath JR. Epitope targeting of tertiary protein structure enables target-guided synthesis of a potent in-cell inhibitor of botulinum neurotoxin. Angew Chem Int Ed Engl 2015; 54:7114-9. [PMID: 25925721 DOI: 10.1002/anie.201502451] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/09/2015] [Indexed: 12/14/2022]
Abstract
Botulinum neurotoxin (BoNT) serotype A is the most lethal known toxin and has an occluded structure, which prevents direct inhibition of its active site before it enters the cytosol. Target-guided synthesis by in situ click chemistry is combined with synthetic epitope targeting to exploit the tertiary structure of the BoNT protein as a landscape for assembling a competitive inhibitor. A substrate-mimicking peptide macrocycle is used as a direct inhibitor of BoNT. An epitope-targeting in situ click screen is utilized to identify a second peptide macrocycle ligand that binds to an epitope that, in the folded BoNT structure, is active-site-adjacent. A second in situ click screen identifies a molecular bridge between the two macrocycles. The resulting divalent inhibitor exhibits an in vitro inhibition constant of 165 pM against the BoNT/A catalytic chain. The inhibitor is carried into cells by the intact holotoxin, and demonstrates protection and rescue of BoNT intoxication in a human neuron model.
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Affiliation(s)
- Blake Farrow
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA).,Department of Applied Physics and Materials Science, California Institute of Technology (USA)
| | - Michelle Wong
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Jacquie Malette
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Bert Lai
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Kaycie M Deyle
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Samir Das
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Arundhati Nag
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Heather D Agnew
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - James R Heath
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA).
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10
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Tso SC, Gui WJ, Wu CY, Chuang JL, Qi X, Skvora KJ, Dork K, Wallace AL, Morlock LK, Lee BH, Hutson SM, Strom SC, Williams NS, Tambar UK, Wynn RM, Chuang DT. Benzothiophene carboxylate derivatives as novel allosteric inhibitors of branched-chain α-ketoacid dehydrogenase kinase. J Biol Chem 2015; 289:20583-93. [PMID: 24895126 DOI: 10.1074/jbc.m114.569251] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The mitochondrial branched-chain α-ketoacid dehydrogenase complex (BCKDC) is negatively regulated by reversible phosphorylation.BCKDC kinase (BDK) inhibitors that augment BCKDC flux have been shown to reduce branched-chain amino acid (BCAA) concentrations in vivo. In the present study, we employed high-throughput screens to identify compound 3,6- dichlorobenzo[b]thiophene-2-carboxylic acid (BT2) as a novel BDK inhibitor (IC(50) = 3.19 μM). BT2 binds to the same site in BDK as other known allosteric BDK inhibitors, including (S)-α-cholorophenylproprionate ((S)-CPP). BT2 binding to BDK triggers helix movements in the N-terminal domain, resulting in the dissociation of BDK from the BCKDC accompanied by accelerated degradation of the released kinase in vivo. BT2 shows excellent pharmacokinetics (terminal T(1⁄2) = 730 min) and metabolic stability (no degradation in 240 min), which are significantly better than those of (S)-CPP. BT2, its analog 3-chloro-6-fluorobenzo[ b]thiophene-2-carboxylic acid (BT2F), and a prodrug of BT2 (i.e. N-(4-acetamido-1,2,5-oxadiazol-3-yl)-3,6-dichlorobenzo[ b]thiophene-2-carboxamide (BT3)) significantly increase residual BCKDC activity in cultured cells and primary hepatocytes from patients and a mouse model of maple syrup urine disease. Administration of BT2 at 20 mg/kg/day to wild-type mice for 1 week leads to nearly complete dephosphorylation and maximal activation of BCKDC in heart, muscle, kidneys, and liver with reduction in plasma BCAA concentrations. The availability of benzothiophene carboxylate derivatives as stable BDK inhibitors may prove useful for the treatment of metabolic disease caused by elevated BCAA concentrations.
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11
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Ai T, Xu Y, Qiu L, Geraghty RJ, Chen L. Hydroxamic Acids Block Replication of Hepatitis C Virus. J Med Chem 2014; 58:785-800. [DOI: 10.1021/jm501330g] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Teng Ai
- Center for Drug Design, Academic
Health Center, University of Minnesota, 516 Delaware Street S.E., Minneapolis, Minnesota 55455, United States
| | - Yanli Xu
- Center for Drug Design, Academic
Health Center, University of Minnesota, 516 Delaware Street S.E., Minneapolis, Minnesota 55455, United States
| | - Li Qiu
- Center for Drug Design, Academic
Health Center, University of Minnesota, 516 Delaware Street S.E., Minneapolis, Minnesota 55455, United States
| | - Robert J. Geraghty
- Center for Drug Design, Academic
Health Center, University of Minnesota, 516 Delaware Street S.E., Minneapolis, Minnesota 55455, United States
| | - Liqiang Chen
- Center for Drug Design, Academic
Health Center, University of Minnesota, 516 Delaware Street S.E., Minneapolis, Minnesota 55455, United States
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12
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Videnović M, Opsenica DM, Burnett J, Gomba L, Nuss JE, Selaković Ž, Konstantinović J, Krstić M, Šegan S, Zlatović M, Sciotti RJ, Bavari S, Šolaja BA. Second generation steroidal 4-aminoquinolines are potent, dual-target inhibitors of the botulinum neurotoxin serotype A metalloprotease and P. falciparum malaria. J Med Chem 2014; 57:4134-53. [PMID: 24742203 PMCID: PMC4032193 DOI: 10.1021/jm500033r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 01/25/2023]
Abstract
Significantly more potent second generation 4-amino-7-chloroquinoline (4,7-ACQ) based inhibitors of the botulinum neurotoxin serotype A (BoNT/A) light chain were synthesized. Introducing an amino group at the C(3) position of the cholate component markedly increased potency (IC50 values for such derivatives ranged from 0.81 to 2.27 μM). Two additional subclasses were prepared: bis(steroidal)-4,7-ACQ derivatives and bis(4,7-ACQ)cholate derivatives; both classes provided inhibitors with nanomolar-range potencies (e.g., the Ki of compound 67 is 0.10 μM). During BoNT/A challenge using primary neurons, select derivatives protected SNAP-25 by up to 89%. Docking simulations were performed to rationalize the compounds' in vitro potencies. In addition to specific residue contacts, coordination of the enzyme's catalytic zinc and expulsion of the enzyme's catalytic water were a consistent theme. With respect to antimalarial activity, the compounds provided better IC90 activities against chloroquine resistant (CQR) malaria than CQ, and seven compounds were more active than mefloquine against CQR strain W2.
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Affiliation(s)
- Milica Videnović
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Dejan M. Opsenica
- Institute
of Chemistry, Technology, and Metallurgy, University of Belgrade, Njegoseva 12, 11000 Belgrade, Serbia
| | - James
C. Burnett
- Computational
Drug Development Group, Leidos Biomedical
Research, Inc., FNLCR at Frederick, P.O.
Box B, Frederick, Maryland 21701, United States
| | - Laura Gomba
- Department
of Bacteriology, United States Army Medical
Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Jonathan E. Nuss
- Department
of Bacteriology, United States Army Medical
Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Života Selaković
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Jelena Konstantinović
- Faculty
of Chemistry Innovative Centre, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Maja Krstić
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Sandra Šegan
- Institute
of Chemistry, Technology, and Metallurgy, University of Belgrade, Njegoseva 12, 11000 Belgrade, Serbia
| | - Mario Zlatović
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
| | - Richard J. Sciotti
- Division
of Experimental Therapeutics, Walter Reed
Army Institute of Research, Silver
Spring, Maryland 20910, United States
| | - Sina Bavari
- Target
Discovery and Experimental Microbiology, United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, Maryland 21702, United States
| | - Bogdan A. Šolaja
- Faculty
of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, 11158, Belgrade, Serbia
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Caglič D, Krutein MC, Bompiani KM, Barlow DJ, Benoni G, Pelletier JC, Reitz AB, Lairson LL, Houseknecht KL, Smith GR, Dickerson TJ. Identification of clinically viable quinolinol inhibitors of botulinum neurotoxin A light chain. J Med Chem 2014; 57:669-76. [PMID: 24387280 PMCID: PMC3983388 DOI: 10.1021/jm4012164] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Botulinum neurotoxins (BoNT) are the most potent toxins known and a significant bioterrorist threat. Few small molecule compounds have been identified that are active in cell-based or animal models, potentially due to toxin enzyme plasticity. Here we screened commercially available quinolinols, as well as synthesized hydroxyquinolines. Seventy-two compounds had IC50 values below 10 μM, with the best compound exhibiting submicromolar inhibition (IC50 = 0.8 μM). Structure-activity relationship trends showed that the enzyme tolerates various substitutions at R1 but has a clear preference for bulky aryl amide groups at R2, while methylation at R3 increased inhibitor potency. Evaluation of the most potent compounds in an ADME panel showed that these compounds possess poor solubility at pH 6.8, but display excellent solubility at low pH, suggesting that oral dosing may be possible. Our data show the potential of quinolinol compounds as BoNT therapeutics due to their good in vitro potencies and favorable ADME properties.
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Affiliation(s)
- Dejan Caglič
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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Caglič D, Bompiani KM, Krutein MC, Čapek P, Dickerson TJ. A high-throughput-compatible FRET-based platform for identification and characterization of botulinum neurotoxin light chain modulators. J Vis Exp 2013:50908. [PMID: 24430674 DOI: 10.3791/50908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is a potent and potentially lethal bacterial toxin that binds to host motor neurons, is internalized into the cell, and cleaves intracellular proteins that are essential for neurotransmitter release. BoNT is comprised of a heavy chain (HC), which mediates host cell binding and internalization, and a light chain (LC), which cleaves intracellular host proteins essential for acetylcholine release. While therapies that inhibit toxin binding/internalization have a small time window of administration, compounds that target intracellular LC activity have a much larger time window of administrations, particularly relevant given the extremely long half-life of the toxin. In recent years, small molecules have been heavily analyzed as potential LC inhibitors based on their increased cellular permeability relative to larger therapeutics (peptides, aptamers, etc.). Lead identification often involves high-throughput screening (HTS), where large libraries of small molecules are screened based on their ability to modulate therapeutic target function. Here we describe a FRET-based assay with a commercial BoNT/A LC substrate and recombinant LC that can be automated for HTS of potential BoNT inhibitors. Moreover, we describe a manual technique that can be used for follow-up secondary screening, or for comparing the potency of several candidate compounds.
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Affiliation(s)
- Dejan Caglič
- Department of Chemistry, The Scripps Research Institute
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Smith GR, Caglič D, Capek P, Zhang Y, Godbole S, Reitz AB, Dickerson TJ. Reexamining hydroxamate inhibitors of botulinum neurotoxin serotype A: extending towards the β-exosite. Bioorg Med Chem Lett 2012; 22:3754-7. [PMID: 22542019 DOI: 10.1016/j.bmcl.2012.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic proteins known to man, exposure to which results in flaccid paralysis. Given their extreme potency, these proteins have become studied as possible weapons of bioterrorism; however, effective treatments that function after intoxication have not progressed to the clinic. Here, we have reexamined one of the most effective inhibitors, 2,4-dichlorocinnamyl hydroxamate, in the context of the known plasticity of the BoNT/A light chain metalloprotease. Our studies have shown that modifications of this compound are tolerated and result in improved inhibitors, with the best compound having an IC(50) of 0.23 μM. Given the inconsistency of structure-activity relationship trends observed across similar compounds, this data argues for caution in extrapolating across structural series.
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Affiliation(s)
- Garry R Smith
- Fox Chase Chemical Diversity Center, Doylestown, PA 18902, USA
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