1
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Feng J, Liu H, Yao Y, Lu CD. Mannich-Type Reaction of α-Sulfanyl N- tert-Butanesulfinylimidates: Diastereoselective Access to α-Mercapto-β-amino Acid Derivatives. J Org Chem 2021; 86:3049-3058. [PMID: 33507079 DOI: 10.1021/acs.joc.0c02583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of α-mercapto-β-amino acid derivatives were synthesized diastereoselectively in good yields through the aza-enolization of α-sulfanyl N-tert-butanesulfinylimidates, followed by their nucleophilic addition to N-tosyl imines via a Mannich-type reaction. The resulting derivatives bearing a β-sulfonylamino sulfide moiety participated in further inter- and intramolecular transformations involving episulfonium ion intermediates generated through neighboring-group participation.
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Affiliation(s)
- Jie Feng
- Key Laboratory of Plant Resources and Chemistry of Arid Zones, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Liu
- Key Laboratory of Plant Resources and Chemistry of Arid Zones, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, Urumqi 830011, China
| | - Yun Yao
- School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Chong-Dao Lu
- School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
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2
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Yang M, Cao T, Xu T, Liao S. Visible-Light-Induced Deaminative Thioesterification of Amino Acid Derived Katritzky Salts via Electron Donor-Acceptor Complex Formation. Org Lett 2019; 21:8673-8678. [PMID: 31638821 DOI: 10.1021/acs.orglett.9b03284] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A visible-light-mediated deaminative thioesterification of amino acid derived Katritzky salts with thiobenzoic acid has been developed, which provides a novel synthetic method for the synthesis of α-mercapto acid derivatives under mild conditions. This photoredox catalyst-free generation of alkyl radicals via C-N bond cleavage is enabled by the formation of an electron-donor-acceptor (EDA) complex between the Katritzky salt and thiobenzoic acid anion, which represents a new entry for EDA complex chemistry.
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Affiliation(s)
- Mingcheng Yang
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry , Fuzhou University , 2 Xueyuan Road , Fuzhou 350116 , P.R. China
| | - Tianpeng Cao
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry , Fuzhou University , 2 Xueyuan Road , Fuzhou 350116 , P.R. China
| | - Tianxiao Xu
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry , Fuzhou University , 2 Xueyuan Road , Fuzhou 350116 , P.R. China
| | - Saihu Liao
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry , Fuzhou University , 2 Xueyuan Road , Fuzhou 350116 , P.R. China.,Beijing National Laboratory for Molecular Sciences (BNLMS) , Fuzhou University , Fuzhou 350116 , P.R. China
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3
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Dai X, Liu M, Huang M, Zhang J, Xu X, Yuan W, Zhang X. Synthesis of Chiral α‐Mercapto‐β‐acylamido Esters via One‐Pot Asymmetric Hydrosilylation−transacylation of α‐Acylthio‐β‐Enamino Esters. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xingjie Dai
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
- University of Chinese Academy of Sciences Beijing China
| | - Min Liu
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
- University of Chinese Academy of Sciences Beijing China
| | - Min Huang
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
- University of Chinese Academy of Sciences Beijing China
| | - Jiayan Zhang
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
- University of Chinese Academy of Sciences Beijing China
| | - Xiaoying Xu
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
| | - Weicheng Yuan
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
| | - Xiaomei Zhang
- Asymmetric Synthesis and Chiraltechnology Key Laboratory of Sichuan Province Chengdu Institute of Organic ChemistryChinese Academy of Sciences Chengdu China
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4
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Pirazzini M, Rossetto O. Challenges in searching for therapeutics against Botulinum Neurotoxins. Expert Opin Drug Discov 2017; 12:497-510. [DOI: 10.1080/17460441.2017.1303476] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Xiao G, Ma C, Xing D, Hu W. Enantioselective Synthesis of α-Mercapto-β-amino Esters via Rh(II)/Chiral Phosphoric Acid-Cocatalyzed Three-Component Reaction of Diazo Compounds, Thiols, and Imines. Org Lett 2016; 18:6086-6089. [DOI: 10.1021/acs.orglett.6b03075] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Guolan Xiao
- Shanghai Engineering
Research
Center of Molecular Therapeutics and New Drug Development, School
of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Chaoqun Ma
- Shanghai Engineering
Research
Center of Molecular Therapeutics and New Drug Development, School
of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Dong Xing
- Shanghai Engineering
Research
Center of Molecular Therapeutics and New Drug Development, School
of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
| | - Wenhao Hu
- Shanghai Engineering
Research
Center of Molecular Therapeutics and New Drug Development, School
of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China
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6
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Kano T, Sakamoto R, Maruoka K. Remote chirality control based on the organocatalytic asymmetric Mannich reaction of α-thio acetaldehydes. Chem Commun (Camb) 2014; 50:942-4. [DOI: 10.1039/c3cc47827k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Microbial and fungal protease inhibitors--current and potential applications. Appl Microbiol Biotechnol 2012; 93:1351-75. [PMID: 22218770 PMCID: PMC7080157 DOI: 10.1007/s00253-011-3834-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 12/07/2011] [Accepted: 12/09/2011] [Indexed: 01/18/2023]
Abstract
Proteolytic enzymes play essential metabolic and regulatory functions in many biological processes and also offer a wide range of biotechnological applications. Because of their essential roles, their proteolytic activity needs to be tightly regulated. Therefore, small molecules and proteins that inhibit proteases can be versatile tools in the fields of medicine, agriculture and biotechnology. In medicine, protease inhibitors can be used as diagnostic or therapeutic agents for viral, bacterial, fungal and parasitic diseases as well as for treating cancer and immunological, neurodegenerative and cardiovascular diseases. They can be involved in crop protection against plant pathogens and herbivorous pests as well as against abiotic stress such as drought. Furthermore, protease inhibitors are indispensable in protein purification procedures to prevent undesired proteolysis during heterologous expression or protein extraction. They are also valuable tools for simple and effective purification of proteases, using affinity chromatography. Because there are such a large number and diversity of proteases in prokaryotes, yeasts, filamentous fungi and mushrooms, we can expect them to be a rich source of protease inhibitors as well.
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8
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Thanongsaksrikul J, Chaicumpa W. Botulinum neurotoxins and botulism: a novel therapeutic approach. Toxins (Basel) 2011; 3:469-88. [PMID: 22069720 PMCID: PMC3202833 DOI: 10.3390/toxins3050469] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 04/22/2011] [Accepted: 04/28/2011] [Indexed: 01/01/2023] Open
Abstract
Specific treatment is not available for human botulism. Current remedial mainstay is the passive administration of polyclonal antibody to botulinum neurotoxin (BoNT) derived from heterologous species (immunized animal or mouse hybridoma) together with supportive and symptomatic management. The antibody works extracellularly, probably by blocking the binding of receptor binding (R) domain to the neuronal receptors; thus inhibiting cellular entry of the holo-BoNT. The antibody cannot neutralize the intracellular toxin. Moreover, a conventional antibody with relatively large molecular size (150 kDa) is not accessible to the enzymatic groove and, thus, cannot directly inhibit the BoNT zinc metalloprotease activity. Recently, a 15-20 kDa single domain antibody (V(H)H) that binds specifically to light chain of BoNT serotype A was produced from a humanized-camel VH/V(H)H phage display library. The V(H)H has high sequence homology (>80%) to the human VH and could block the enzymatic activity of the BoNT. Molecular docking revealed not only the interface binding between the V(H)H and the toxin but also an insertion of the V(H)H CDR3 into the toxin enzymatic pocket. It is envisaged that, by molecular linking the V(H)H to a cell penetrating peptide (CPP), the CPP-V(H)H fusion protein would be able to traverse the hydrophobic cell membrane into the cytoplasm and inhibit the intracellular BoNT. This presents a novel and safe immunotherapeutic strategy for botulism by using a cell penetrating, humanized-single domain antibody that inhibits the BoNT by means of a direct blockade of the groove of the menace enzyme.
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Affiliation(s)
- Jeeraphong Thanongsaksrikul
- Laboratory for Research and Technology Development, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkok-noi, Bangkok 10700, Thailand.
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9
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Salzameda NT, Eubanks LM, Zakhari JS, Tsuchikama K, DeNunzio NJ, Allen KN, Hixon MS, Janda KD. A cross-over inhibitor of the botulinum neurotoxin light chain B: a natural product implicating an exosite mechanism of action. Chem Commun (Camb) 2011; 47:1713-5. [PMID: 21203627 DOI: 10.1039/c0cc04078a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Clostridium botulinum produces the most lethal toxins known to man, as such they are high risk terrorist threats, and alarmingly there is no approved therapeutic. We report the first cross-over small molecule inhibitor of these neurotoxins and propose a mechanism by which it may impart its inhibitory activity.
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Affiliation(s)
- Nicholas T Salzameda
- Department of Chemistry, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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10
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Ramanjaneyulu GS, Darshan DV, Mahendar K, Kantam ML, Prabhakar S. Differentiation of diasteromeric α-sulfanyl-β-amino acid derivatives by electrospray ionization tandem mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2011; 17:265-275. [PMID: 21828420 DOI: 10.1255/ejms.1119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A set of diastereomeric α-sulfanyl-β-amino acid derivatives, which are important building blocks for pharmaceuticals with potent biological activity, are studied by electrospray ionization tandem mass spectrometry. The collision induced dissociation (CID) spectra of [M+H](+), [M+NH(4)](+), [M+Na](+) and [M+Li](+) of the diastereomers were studied, among them the CID of [M+Na](+) and [M+Li](+) showed consistent differences in the relative abundance of characteristic ions that enabled distinction of the anti isomers from syn isomers. The decomposition pathways for the diagnostic ions were arrived at based on high-resolution mass spectrometry data, multiple mass spectrometry data, deuterium labeling experiments and the mass shift in accordance with the substituents located at different places. Loss of (R(1)-C(6)H(4)-CH=NH) and (Cat-NH-SO(2)R(2)) from [M+Cat](+), where Cat=Na and Li, and the product ions as a results of McLafferty rearrangement involving either >S=O or >C=O group were found to be diagnostic. The McLafferty rearrangement product ions involving >S=O group were more abundant in syn isomers while those involving >C=O group were more abundant in anti isomer. The selectivity observed in the decomposition of [M+Li](+) ions was found to be similar to that of [M+Na](+) ions, but in few cases the differences are marginal in the decomposition [M+Li](+) ions.
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Affiliation(s)
- Gundimeda S Ramanjaneyulu
- National Centre for Mass Spectrometry, Indian Institute of Chemical Technology, Hyderabad 500 007, India
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11
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Synthesis of novel tetrahydroisoquinoline bronchodilators. Bioorg Med Chem Lett 2010; 20:4999-5003. [DOI: 10.1016/j.bmcl.2010.07.057] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 07/13/2010] [Accepted: 07/14/2010] [Indexed: 11/19/2022]
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12
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Kantam ML, Mahendar K, Sreedhar B, Choudary BM, Bhargava SK, Priver SH. Synthesis of α-sulfanyl-β-amino acid derivatives by using nanocrystalline magnesium oxide. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Potent new small-molecule inhibitor of botulinum neurotoxin serotype A endopeptidase developed by synthesis-based computer-aided molecular design. PLoS One 2009; 4:e7730. [PMID: 19901994 PMCID: PMC2771286 DOI: 10.1371/journal.pone.0007730] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 10/13/2009] [Indexed: 11/19/2022] Open
Abstract
Botulinum neurotoxin serotype A (BoNTA) causes a life-threatening neuroparalytic disease known as botulism. Current treatment for post exposure of BoNTA uses antibodies that are effective in neutralizing the extracellular toxin to prevent further intoxication but generally cannot rescue already intoxicated neurons. Effective small-molecule inhibitors of BoNTA endopeptidase (BoNTAe) are desirable because such inhibitors potentially can neutralize the intracellular BoNTA and offer complementary treatment for botulism. Previously we reported a serotype-selective, small-molecule BoNTAe inhibitor with a Kiapp value of 3.8±0.8 µM. This inhibitor was developed by lead identification using virtual screening followed by computer-aided optimization of a lead with an IC50 value of 100 µM. However, it was difficult to further improve the lead from micromolar to even high nanomolar potency due to the unusually large enzyme-substrate interface of BoNTAe. The enzyme-substrate interface area of 4,840 Å2 for BoNTAe is about four times larger than the typical protein-protein interface area of 750–1,500 Å2. Inhibitors must carry several functional groups to block the unusually large interface of BoNTAe, and syntheses of such inhibitors are therefore time-consuming and expensive. Herein we report the development of a serotype-selective, small-molecule, and competitive inhibitor of BoNTAe with a Ki value of 760±170 nM using synthesis-based computer-aided molecular design (SBCAMD). This new approach accounts the practicality and efficiency of inhibitor synthesis in addition to binding affinity and selectivity. We also report a three-dimensional model of BoNTAe in complex with the new inhibitor and the dynamics of the complex predicted by multiple molecular dynamics simulations, and discuss further structural optimization to achieve better in vivo efficacy in neutralizing BoNTA than those of our early micromolar leads. This work provides new insight into structural modification of known small-molecule BoNTAe inhibitors. It also demonstrates that SBCAMD is capable of improving potency of an inhibitor lead by nearly one order of magnitude, even for BoNTAe as one of the most challenging protein targets. The results are insightful for developing effective small-molecule inhibitors of protein targets with large active sites.
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14
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Yu R, Wang S, Yu YZ, Du WS, Yang F, Yu WY, Sun ZW. Neutralizing antibodies of botulinum neurotoxin serotype A screened from a fully synthetic human antibody phage display library. ACTA ACUST UNITED AC 2009; 14:991-8. [PMID: 19726786 DOI: 10.1177/1087057109343206] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The botulinum neurotoxins (BoNTs) produced by Clostridium botulinum are the most poisonous protein substances known. The neutralizing antibodies against botulinum neurotoxin can effectively prevent and cure the toxicosis. Using purified Hc fragments of botulinum neurotoxin serotype A (BoNT/A-Hc) as antigen, 2 specific neutralizing antibodies mapping different epitopes were selected from a fully synthetic human antibody library. The 2 antibodies can effectively inhibit the binding between BoNT/A-Hc and differentiated PC-12 cells in vitro, and the neutralization was evaluated in vivo. Although no single mAb completely protected mice from toxin, they both could prolong time to death when challenged with 20 LD(50)s (50% lethal doses) of BoNT/A. When used together, the mAbs completely neutralized 1000 LD(50)s/mg Ab, suggesting their high neutralizing potency in vivo. The results would lead to further production of neutralizing antibody drugs against BoNT/A. It also proved that it was a quick method to obtain human therapeutic antibodies by selecting from the fully synthetic human antibody phage display library.
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Affiliation(s)
- Rui Yu
- Beijing Institute of Biotechnology, Beijing, China
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15
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Salzameda NT, Barbieri JT, Janda KD. Synthetic substrate for application in both high and low throughput assays for botulinum neurotoxin B protease inhibitors. Bioorg Med Chem Lett 2009; 19:5848-50. [PMID: 19747823 DOI: 10.1016/j.bmcl.2009.08.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 08/20/2009] [Accepted: 08/24/2009] [Indexed: 10/20/2022]
Abstract
A FRET peptide substrate was synthesized and evaluated for enzymatic cleavage by the BoNT/B light chain protease. The FRET substrate was found to be useful in both a high throughput assay to uncover initial 'hits' and a low throughput HPLC assay to determine kinetic parameters and modes of inhibition.
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Affiliation(s)
- Nicholas T Salzameda
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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16
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Capková K, Salzameda NT, Janda KD. Investigations into small molecule non-peptidic inhibitors of the botulinum neurotoxins. Toxicon 2009; 54:575-82. [PMID: 19327377 DOI: 10.1016/j.toxicon.2009.03.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 03/03/2009] [Accepted: 03/03/2009] [Indexed: 11/18/2022]
Abstract
Botulinum neurotoxins (BoNTs), proteins secreted by the bacteria genus Clostridium, represent a group of extremely lethal toxins and a potential bioterrorism threat. As the current therapeutic options are of a predominantly prophylactic nature and cannot be used en masse, new strategies and ultimately potential treatments are desperately needed to combat any widespread release of these neurotoxins. In these regards, our laboratory has been working on developing new alternatives to treat botulinum intoxication through the development of inhibitors of the light chain proteases, the etiological agent which causes BoNT intoxication. Such a strategy has required the construction of two high-throughput screens and small molecule non-peptidic libraries; excitingly, inhibitors of the BoNT/A protease have been uncovered and are being optimized via structure activity relationship studies.
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Affiliation(s)
- Katerina Capková
- Departments of Chemistry and Immunology, and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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17
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Willis B, Eubanks LM, Dickerson TJ, Janda KD. The strange case of the botulinum neurotoxin: using chemistry and biology to modulate the most deadly poison. Angew Chem Int Ed Engl 2008; 47:8360-79. [PMID: 18844202 DOI: 10.1002/anie.200705531] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the classic novella "The Strange Case of Dr. Jekyll and Mr. Hyde", Robert Louis Stevenson paints a stark picture of the duality of good and evil within a single man. Botulinum neurotoxin (BoNT), the most potent known toxin, possesses an analogous dichotomous nature: It shows a pronounced morbidity and mortality, but it is used with great effect in much lower doses in a wide range of clinical scenarios. Recently, tremendous strides have been made in the basic understanding of the structure and function of BoNT, which have translated into widespread efforts towards the discovery of biomacromolecules and small molecules that specifically modulate BoNT activity. Particular emphasis has been placed on the identification of inhibitors that can counteract BoNT exposure in the event of a bioterrorist attack. This Review summarizes the current advances in the development of therapeutics, including vaccines, peptides, and small-molecule inhibitors, for the prevention and treatment of botulism.
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Affiliation(s)
- Bert Willis
- Department of Chemistry, Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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18
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Willis B, Eubanks L, Dickerson T, Janda K. Der seltsame Fall des Botulinum-Neurotoxins: chemische und biologische Modulierung des tödlichsten aller Gifte. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200705531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Agarwal R, Swaminathan S. SNAP-25 substrate peptide (residues 180-183) binds to but bypasses cleavage by catalytically active Clostridium botulinum neurotoxin E. J Biol Chem 2008; 283:25944-51. [PMID: 18658150 DOI: 10.1074/jbc.m803756200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clostridium botulinum neurotoxins are the most potent toxins to humans. The recognition and cleavage of SNAREs are prime evente in exhibiting their toxicity. We report here the crystal structure of the catalytically active full-length botulinum serotype E catalytic domain (BoNT E) in complex with SNAP-25 (a SNARE protein) substrate peptide Arg(180)-Ile(181)-Met(182)-Glu(183) (P1-P3'). It is remarkable that the peptide spanning the scissile bond binds to but bypasses cleavage by the enzyme and inhibits the catalysis fairly with K(i) approximately 69 microm. The inhibitory peptide occupies the active site of BoNT E and shows well defined electron density. The catalytic zinc and the conserved key residue Tyr(350) of the enzyme facilitate the docking of Arg(180) (P1) by interacting with its carbonyl oxygen that displaces the nucleophilic water. The general base Glu(212) side chain interacts with the main chain amino group of P1 and P1'. Conserved Arg(347) of BoNT E stabilizes the proper docking of the Ile(181) (P1') main chain, whereas the hydrophobic pockets stabilize the side chains of Ile(181) (P1') and Met(182) (P2'), and the 250 loop stabilizes Glu(183) (P3'). Structural and functional analysis revealed an important role for the P1' residue and S1' pocket in driving substrate recognition and docking at the active site. This study is the first of its kind and rationalizes the substrate cleavage strategy of BoNT E. Also, our complex structure opens up an excellent opportunity of structure-based drug design for this fast acting and extremely toxic high priority BoNT E.
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Affiliation(s)
- Rakhi Agarwal
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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20
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Ring-opening of oxazolines derived from l-serine: a short and efficient stereoselective synthesis of all four diastereomers of 3-mercaptoaspartic acid derivatives. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.08.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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21
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Silvaggi NR, Boldt GE, Hixon MS, Kennedy JP, Tzipori S, Janda KD, Allen KN. Structures of Clostridium botulinum Neurotoxin Serotype A Light Chain complexed with small-molecule inhibitors highlight active-site flexibility. ACTA ACUST UNITED AC 2007; 14:533-42. [PMID: 17524984 DOI: 10.1016/j.chembiol.2007.03.014] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 02/07/2007] [Accepted: 03/14/2007] [Indexed: 11/19/2022]
Abstract
The potential for the use of Clostridial neurotoxins as bioweapons makes the development of small-molecule inhibitors of these deadly toxins a top priority. Recently, screening of a random hydroxamate library identified a small-molecule inhibitor of C. botulinum Neurotoxin Serotype A Light Chain (BoNT/A-LC), 4-chlorocinnamic hydroxamate, a derivative of which has been shown to have in vivo efficacy in mice and no toxicity. We describe the X-ray crystal structures of BoNT/A-LC in complexes with two potent small-molecule inhibitors. The structures of the enzyme with 4-chlorocinnamic hydroxamate or 2,4-dichlorocinnamic hydroxamate bound are compared to the structure of the enzyme complexed with L-arginine hydroxamate, an inhibitor with modest affinity. Taken together, this suite of structures provides surprising insights into the BoNT/A-LC active site, including unexpected conformational flexibility at the S1' site that changes the electrostatic environment of the binding pocket. Information gained from these structures will inform the design and optimization of more effective small-molecule inhibitors of BoNT/A-LC.
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Affiliation(s)
- Nicholas R Silvaggi
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
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22
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Fang H, Luo W, Henkel J, Barbieri J, Green N. A yeast assay probes the interaction between botulinum neurotoxin serotype B and its SNARE substrate. Proc Natl Acad Sci U S A 2006; 103:6958-63. [PMID: 16636286 PMCID: PMC1447522 DOI: 10.1073/pnas.0510816103] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The seven functionally distinct serotypes (A-G) of botulinum neurotoxin (BoNT) are dichains consisting of light chain (LC) with zinc-dependent endoprotease activity connected by one disulfide bond to heavy chain with neuronal-cell translocation and receptor-binding domains. LC-mediated proteolysis of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and consequent inhibition of synaptic vesicle fusion to the presynaptic membrane of human motor neurons are responsible for flaccid paralysis associated with botulism. LC endoproteolysis is complex, requiring highly extended SNARE sequences at the surface of intracellular membranes and prompting our development of a genetically amenable assay to monitor the interaction between BoNT/LC and its SNARE substrate. Using BoNT serotype B as a model, the assay employs a chimeric SNARE protein where a portion of neuronal synaptobrevin (Sb) is fused to Snc2p, a Sb ortholog required for protein secretion from yeast cells. Regulated expression of serotype B-LC in yeast leads to cleavage of the chimera and a conditional growth defect. To assess utility of this assay for monitoring SNARE protein cleavage, we growth-selected chimeric SNARE mutations that inhibited proteolysis. When these mutations were introduced into Sb and examined for cleavage, substrate residues located near and distal to the cleavage site were important, including residues positioned near the Sb transmembrane domain, an unexplored aspect of BoNT cell intoxication. Additional mutations were positioned in a nine-residue SNARE motif, supporting a previously assigned role for this motif in LC recognition and providing proof of principle for the application of yeast-based technology to study intracellular BoNT/LC endoproteases.
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Affiliation(s)
- Hong Fang
- Department of Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232-2363, USA.
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Candela-Lena JI, Davies SG, Roberts PM, Roux B, Russell AJ, Sánchez-Fernández EM, Smith AD. Asymmetric synthesis of α-mercapto-β-amino acid derivatives: application to the synthesis of polysubstituted thiomorpholines. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.tetasy.2006.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Park JG, Sill PC, Makiyi EF, Garcia-Sosa AT, Millard CB, Schmidt JJ, Pang YP. Serotype-selective, small-molecule inhibitors of the zinc endopeptidase of botulinum neurotoxin serotype A. Bioorg Med Chem 2005; 14:395-408. [PMID: 16203152 DOI: 10.1016/j.bmc.2005.08.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 08/08/2005] [Accepted: 08/09/2005] [Indexed: 10/25/2022]
Abstract
Botulinum neurotoxin serotype A (BoNTA) is one of the most toxic substances known. Currently, there is no antidote to BoNTA. Small molecules identified from high-throughput screening reportedly inhibit the endopeptidase--the zinc-bound, catalytic domain of BoNTA--at a drug concentration of 20 microM. However, optimization of these inhibitors is hampered by challenges including the computational evaluation of the ability of a zinc ligand to compete for coordination with nearby residues in the active site of BoNTA. No improved inhibitor of the endopeptidase has been reported. This article reports the development of a serotype-selective, small-molecule inhibitor of BoNTA with a K(i) of 12 microM. This inhibitor was designed to coordinate the zinc ion embedded in the active site of the enzyme for affinity and to interact with a species-specific residue in the active site for selectivity. It is the most potent small-molecule inhibitor of BoNTA reported to date. The results suggest that multiple molecular dynamics simulations using the cationic dummy atom approach are useful to structure-based design of zinc protease inhibitors.
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Affiliation(s)
- Jewn Giew Park
- Computer-Aided Molecular Design Laboratory, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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Anne C, Turcaud S, Blommaert AGS, Darchen F, Johnson EA, Roques BP. Partial Protection against Botulinum B Neurotoxin-Induced Blocking of Exocytosis by a Potent Inhibitor of Its Metallopeptidase Activity. Chembiochem 2005; 6:1375-80. [PMID: 15988765 DOI: 10.1002/cbic.200400398] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Clostridium botulinum neurotoxins (BoNTs) cause botulism, which is characterized by a flaccid paralysis, through inhibition of acetylcholine release by peripheral cholinergic nerve terminals. This is due to the zinc metallopeptidase activity of the neurotoxin, cleaving one component (synaptobrevin for BoNT/B) of the exocytosis machinery. Yet, there are no specific agents able to control the peptidase-related effects of BoNT/B. We recently developed the first compounds to inhibit this enzymatic activity in the nanomolar range. Here we report that two of our best inhibitors prevent the BoNT/B-induced cleavage of native synaptobrevin on synaptic vesicles, and partially inhibit the suppression of [3H]noradrenaline release from synaptosomes that is caused by BoNT/B. These results were obtained at micromolar concentrations, consistent with the measured inhibitory potency of these inhibitors on the native toxin. These compounds provide a new way to possibly prevent and/or to control the neurotoxin effects of botulinum.
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Affiliation(s)
- Christine Anne
- Département de Pharmacochimie Moléculaire et Structurale, INSERM U266/CNRS FRE2463, UFR des Sciences Pharmaceutiques et Biologiques, 4 Avenue de l'Observatoire, 75006 Paris, France
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Burnett JC, Henchal EA, Schmaljohn AL, Bavari S. The evolving field of biodefence: therapeutic developments and diagnostics. Nat Rev Drug Discov 2005; 4:281-97. [PMID: 15803193 PMCID: PMC7096857 DOI: 10.1038/nrd1694] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Bioweapons are a clear threat to both military and civilian populations. Here, the latest advances in the pursuit of inhibitors against biothreat threat toxins, current therapeutic strategies for treating biodefence related pathogens, and strategies for improving detection and exposure survivability are covered. There are numerous lead therapeutics that have emerged from drug discovery efforts. However, many of these are toxic and/or fail to possess conventional drug-like properties. One clear advantage of small (non-peptidic) molecules is that they possess scaffolds that are inherently more likely to evolve into real therapeutics. One of the major obstacles impeding the translation of these lead therapeutics into viable drugs is the lack of involvement of the pharmaceutical industry, which has been discovering leads and translating them into drugs for decades. The expertise of the pharmaceutical industry therefore needs to be more effectively engaged in developing drugs against biothreat agents. New methods for rapidly detecting and diagnosing biothreat agents are also in development. The detection and diagnosis of biothreats is inherently linked with treatment. The means for detecting the release of bioweapons are being deployed, and new technologies are shortening the timeframe between initial sample collection and conclusive agent determination. However, the organization of this process is imperfect. At present, a unifying entity that orchestrates the biodefence response is clearly needed to reduce the time-to-drug process and redundancies in drug development efforts. Such a central entity could formulate and implement plans to coordinate all participants, including academic institutions, government agencies and the private sector. This could accelerate the development of countermeasures against high probability biothreat agents.
The threat of bioterrorism and the potential use of biological weapons against both military and civilian populations has become a major concern for governments around the world. For example, in 2001 anthrax-tainted letters resulted in several deaths, caused widespread public panic and exerted a heavy economic toll. If such a small-scale act of bioterrorism could have such a huge impact, then the effects of a large-scale attack would be catastrophic. This review covers recent progress in developing therapeutic countermeasures against, and diagnostics for, such agents.
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Affiliation(s)
- James C. Burnett
- Developmental Therapeutics Program, Target Structure-Based Drug Discovery Group, National Cancer Institute-SAIC, Frederick, 21702 Maryland USA
| | - Erik A. Henchal
- United States Army Medical Research Institute of Infectious Diseases, Frederick, 21702 Maryland USA
| | - Alan L. Schmaljohn
- United States Army Medical Research Institute of Infectious Diseases, Frederick, 21702 Maryland USA
| | - Sina Bavari
- United States Army Medical Research Institute of Infectious Diseases, Frederick, 21702 Maryland USA
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