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Rasetti-Escargueil C, Palea S. Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications. Toxins (Basel) 2024; 16:261. [PMID: 38922155 PMCID: PMC11209287 DOI: 10.3390/toxins16060261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 06/27/2024] Open
Abstract
Botulinum neurotoxins (BoNTs) have been used for almost half a century in the treatment of excessive muscle contractility. BoNTs are routinely used to treat movement disorders such as cervical dystonia, spastic conditions, blepharospasm, and hyperhidrosis, as well as for cosmetic purposes. In addition to the conventional indications, the use of BoNTs to reduce pain has gained increased recognition, giving rise to an increasing number of indications in disorders associated with chronic pain. Furthermore, BoNT-derived formulations are benefiting a much wider range of patients suffering from overactive bladder, erectile dysfunction, arthropathy, neuropathic pain, and cancer. BoNTs are categorised into seven toxinotypes, two of which are in clinical use, and each toxinotype is divided into multiple subtypes. With the development of bioinformatic tools, new BoNT-like toxins have been identified in non-Clostridial organisms. In addition to the expanding indications of existing formulations, the rich variety of toxinotypes or subtypes in the wild-type BoNTs associated with new BoNT-like toxins expand the BoNT superfamily, forming the basis on which to develop new BoNT-based therapeutics as well as research tools. An overview of the diversity of the BoNT family along with their conventional therapeutic uses is presented in this review followed by the engineering and formulation opportunities opening avenues in therapy.
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Affiliation(s)
| | - Stefano Palea
- Humana Biosciences-Prologue Biotech, 516 Rue Pierre et Marie Curie, 31670 Labège, France;
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2
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Rawson AM, Dempster AW, Humphreys CM, Minton NP. Pathogenicity and virulence of Clostridium botulinum. Virulence 2023; 14:2205251. [PMID: 37157163 PMCID: PMC10171130 DOI: 10.1080/21505594.2023.2205251] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Clostridium botulinum, a polyphyletic Gram-positive taxon of bacteria, is classified purely by their ability to produce botulinum neurotoxin (BoNT). BoNT is the primary virulence factor and the causative agent of botulism. A potentially fatal disease, botulism is classically characterized by a symmetrical descending flaccid paralysis, which is left untreated can lead to respiratory failure and death. Botulism cases are classified into three main forms dependent on the nature of intoxication; foodborne, wound and infant. The BoNT, regarded as the most potent biological substance known, is a zinc metalloprotease that specifically cleaves SNARE proteins at neuromuscular junctions, preventing exocytosis of neurotransmitters, leading to muscle paralysis. The BoNT is now used to treat numerous medical conditions caused by overactive or spastic muscles and is extensively used in the cosmetic industry due to its high specificity and the exceedingly small doses needed to exert long-lasting pharmacological effects. Additionally, the ability to form endospores is critical to the pathogenicity of the bacteria. Disease transmission is often facilitated via the metabolically dormant spores that are highly resistant to environment stresses, allowing persistence in the environment in unfavourable conditions. Infant and wound botulism infections are initiated upon germination of the spores into neurotoxin producing vegetative cells, whereas foodborne botulism is attributed to ingestion of preformed BoNT. C. botulinum is a saprophytic bacterium, thought to have evolved its potent neurotoxin to establish a source of nutrients by killing its host.
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Affiliation(s)
- Alexander M Rawson
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
| | - Andrew W Dempster
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
| | - Christopher M Humphreys
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, The Biodiscovery Institute, The University of Nottingham, Nottingham, UK
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3
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Abstract
Botulinum neurotoxins (BoNTs) are multi-domain proteins whose potent and selective actions on nerve endings have led to innovations in both basic and clinical science. The various BoNT domains are responsible for binding to gangliosides and proteins associated with nerve cell membranes, internalization into the cell, and cleavage of one or more SNARE (soluble N-ethylmaleimide sensitive factor attachment protein receptor) proteins necessary for vesicle docking and fusion. Novel modifications to BoNT molecules, such as the creation of chimeras, helped identify the protein domains responsible for various aspects of BoNT action, such as localized effects. Other molecular modifications have been introduced in attempts to increase the specificity of BoNTs for autonomic or sensory neurons, with the ultimate goal of optimizing therapeutic selectivity. This research, in turn, has led to the development of BoNT-based proteins that can target non-SNARE substrates such as phosphatase and tensin homolog (PTEN). Still others are developing different BoNT serotypes, subtypes, or variants that are longer- or shorter-acting or have faster onset for various clinical purposes. New formulations of BoNTs that provide convenience for both patients and physicians are under investigation. Novel clinical uses are being evaluated for onabotulinumtoxinA, including in the prevention of post-operative atrial fibrillation. All these innovations capitalize on the unique properties of BoNTs, which continue to intrigue scientists and clinicians across numerous fields of study.
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Affiliation(s)
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland
| | - Mitchell F Brin
- Allergan/AbbVie, Irvine, CA, USA
- University of California, Irvine, CA, USA
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4
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Dyer RP, Isoda HM, Salcedo GS, Speciale G, Fletcher MH, Le LQ, Liu Y, Brami-Cherrier K, Malik SZ, Vazquez-Cintron EJ, Chu AC, Rupp DC, Jacky BPS, Nguyen TTM, Katz BB, Steward LE, Majumdar S, Brideau-Andersen AD, Weiss GA. Reengineering the specificity of the highly selective Clostridium botulinum protease via directed evolution. Sci Rep 2022; 12:9956. [PMID: 35705606 PMCID: PMC9200782 DOI: 10.1038/s41598-022-13617-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 05/17/2022] [Indexed: 11/10/2022] Open
Abstract
The botulinum neurotoxin serotype A (BoNT/A) cuts a single peptide bond in SNAP25, an activity used to treat a wide range of diseases. Reengineering the substrate specificity of BoNT/A’s protease domain (LC/A) could expand its therapeutic applications; however, LC/A’s extended substrate recognition (≈ 60 residues) challenges conventional approaches. We report a directed evolution method for retargeting LC/A and retaining its exquisite specificity. The resultant eight-mutation LC/A (omLC/A) has improved cleavage specificity and catalytic efficiency (1300- and 120-fold, respectively) for SNAP23 versus SNAP25 compared to a previously reported LC/A variant. Importantly, the BoNT/A holotoxin equipped with omLC/A retains its ability to form full-length holotoxin, infiltrate neurons, and cleave SNAP23. The identification of substrate control loops outside BoNT/A’s active site could guide the design of improved BoNT proteases and inhibitors.
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Affiliation(s)
- Rebekah P Dyer
- Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Hariny M Isoda
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Gabriela S Salcedo
- Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Gaetano Speciale
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Madison H Fletcher
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Linh Q Le
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Yi Liu
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Karen Brami-Cherrier
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Shiazah Z Malik
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | | | - Andrew C Chu
- Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - David C Rupp
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Birgitte P S Jacky
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Thu T M Nguyen
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Benjamin B Katz
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | - Lance E Steward
- Allergan Aesthetics, An AbbVie company, 2525 Dupont Drive, Irvine, CA, 92612, USA
| | - Sudipta Majumdar
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA
| | | | - Gregory A Weiss
- Departments of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA. .,Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA. .,Pharmaceutical Sciences, University of California, Irvine, 1102 NS-2, Irvine, CA, 92697-2025, USA.
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5
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Pirazzini M, Montecucco C, Rossetto O. Toxicology and pharmacology of botulinum and tetanus neurotoxins: an update. Arch Toxicol 2022; 96:1521-1539. [PMID: 35333944 PMCID: PMC9095541 DOI: 10.1007/s00204-022-03271-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/28/2022] [Indexed: 12/27/2022]
Abstract
Tetanus and botulinum neurotoxins cause the neuroparalytic syndromes of tetanus and botulism, respectively, by delivering inside different types of neurons, metalloproteases specifically cleaving the SNARE proteins that are essential for the release of neurotransmitters. Research on their mechanism of action is intensively carried out in order to devise improved therapies based on antibodies and chemical drugs. Recently, major results have been obtained with human monoclonal antibodies and with single chain antibodies that have allowed one to neutralize the metalloprotease activity of botulinum neurotoxin type A1 inside neurons. In addition, a method has been devised to induce a rapid molecular evolution of the metalloprotease domain of botulinum neurotoxin followed by selection driven to re-target the metalloprotease activity versus novel targets with respect to the SNARE proteins. At the same time, an intense and wide spectrum clinical research on novel therapeutics based on botulinum neurotoxins is carried out, which are also reviewed here.
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Affiliation(s)
- Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy.,Centro Interdipartimentale di Ricerca di Miologia, CIR-Myo, University of Padova, Via U. Bassi 58/B, 35131, Padova, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy. .,Institute of Neuroscience, National Research Council, Via Ugo Bassi 58/B, 35131, Padova, Italy.
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy.,Centro Interdipartimentale di Ricerca di Miologia, CIR-Myo, University of Padova, Via U. Bassi 58/B, 35131, Padova, Italy.,Institute of Neuroscience, National Research Council, Via Ugo Bassi 58/B, 35131, Padova, Italy
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6
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Dyer RP, Weiss GA. Making the cut with protease engineering. Cell Chem Biol 2021; 29:177-190. [PMID: 34921772 PMCID: PMC9127713 DOI: 10.1016/j.chembiol.2021.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 07/30/2021] [Accepted: 11/29/2021] [Indexed: 12/30/2022]
Abstract
Proteases cut with enviable precision and regulate diverse molecular events in biology. Such qualities drive a seemingly inexhaustible appetite for proteases with new activities and capabilities. Comprising 25% of the total industrial enzyme market, proteases appear in consumer goods, such as detergents, textile processing, and numerous foods; additionally, proteases include 25 US Food and Drug Administration-approved medicines and various research tools. Recent advances in protease engineering strategies address target specificity, catalytic efficiency, and stability. This guide to protease engineering surveys best practices and emerging strategies. We further highlight gaps and flexibilities inherent to each system that suggest opportunities for new technology development along with engineered proteases to solve challenges in proteomics, protein sequencing, and synthetic gene circuits.
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Affiliation(s)
- Rebekah P Dyer
- Department of Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA 92697-2025, USA
| | - Gregory A Weiss
- Department of Chemistry, University of California, Irvine, 1102 NS-2, Irvine, CA 92697-2025, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, 1102 NS-2, Irvine, CA 92697-2025, USA; Department of Pharmaceutical Sciences, University of California, Irvine, 1102 NS-2, Irvine, CA 92697-2025, USA.
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7
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Wang W, Liu W. PCLasso: a protein complex-based, group lasso-Cox model for accurate prognosis and risk protein complex discovery. Brief Bioinform 2021; 22:6291946. [PMID: 34086850 DOI: 10.1093/bib/bbab212] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/08/2021] [Accepted: 05/15/2021] [Indexed: 12/12/2022] Open
Abstract
For high-dimensional expression data, most prognostic models perform feature selection based on individual genes, which usually lead to unstable prognosis, and the identified risk genes are inherently insufficient in revealing complex molecular mechanisms. Since most genes carry out cellular functions by forming protein complexes-basic representatives of functional modules, identifying risk protein complexes may greatly improve our understanding of disease biology. Coupled with the fact that protein complexes have been shown to have innate resistance to batch effects and are effective predictors of disease phenotypes, constructing prognostic models and selecting features with protein complexes as the basic unit should improve the robustness and biological interpretability of the model. Here, we propose a protein complex-based, group lasso-Cox model (PCLasso) to predict patient prognosis and identify risk protein complexes. Experiments on three cancer types have proved that PCLasso has better prognostic performance than prognostic models based on individual genes. The resulting risk protein complexes not only contain individual risk genes but also incorporate close partners that synergize with them, which may promote the revealing of molecular mechanisms related to cancer progression from a comprehensive perspective. Furthermore, a pan-cancer prognostic analysis was performed to identify risk protein complexes of 19 cancer types, which may provide novel potential targets for cancer research.
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Affiliation(s)
- Wei Wang
- Heilongjiang Institute of Technology, Harbin 150050, China
| | - Wei Liu
- School of Science at Heilongjiang Institute of Technology, Harbin 150050, China
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8
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Blum TR, Liu H, Packer MS, Xiong X, Lee PG, Zhang S, Richter M, Minasov G, Satchell KJF, Dong M, Liu DR. Phage-assisted evolution of botulinum neurotoxin proteases with reprogrammed specificity. Science 2021; 371:803-810. [PMID: 33602850 DOI: 10.1126/science.abf5972] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 12/24/2020] [Indexed: 12/14/2022]
Abstract
Although bespoke, sequence-specific proteases have the potential to advance biotechnology and medicine, generation of proteases with tailor-made cleavage specificities remains a major challenge. We developed a phage-assisted protease evolution system with simultaneous positive and negative selection and applied it to three botulinum neurotoxin (BoNT) light-chain proteases. We evolved BoNT/X protease into separate variants that preferentially cleave vesicle-associated membrane protein 4 (VAMP4) and Ykt6, evolved BoNT/F protease to selectively cleave the non-native substrate VAMP7, and evolved BoNT/E protease to cleave phosphatase and tensin homolog (PTEN) but not any natural BoNT protease substrate in neurons. The evolved proteases display large changes in specificity (218- to >11,000,000-fold) and can retain their ability to form holotoxins that self-deliver into primary neurons. These findings establish a versatile platform for reprogramming proteases to selectively cleave new targets of therapeutic interest.
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Affiliation(s)
- Travis R Blum
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Hao Liu
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Michael S Packer
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Xiaozhe Xiong
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Pyung-Gang Lee
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Michelle Richter
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - George Minasov
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Karla J F Satchell
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA 02115, USA. .,Department of Microbiology and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. .,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.,Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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9
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Rasetti-Escargueil C, Popoff MR. Engineering Botulinum Neurotoxins for Enhanced Therapeutic Applications and Vaccine Development. Toxins (Basel) 2020; 13:1. [PMID: 33374954 PMCID: PMC7821915 DOI: 10.3390/toxins13010001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 02/07/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) show increasing therapeutic applications ranging from treatment of locally paralyzed muscles to cosmetic benefits. At first, in the 1970s, BoNT was used for the treatment of strabismus, however, nowadays, BoNT has multiple medical applications including the treatment of muscle hyperactivity such as strabismus, dystonia, movement disorders, hemifacial spasm, essential tremor, tics, cervical dystonia, cerebral palsy, as well as secretory disorders (hyperhidrosis, sialorrhea) and pain syndromes such as chronic migraine. This review summarizes current knowledge related to engineering of botulinum toxins, with particular emphasis on their potential therapeutic applications for pain management and for retargeting to non-neuronal tissues. Advances in molecular biology have resulted in generating modified BoNTs with the potential to act in a variety of disorders, however, in addition to the modifications of well characterized toxinotypes, the diversity of the wild type BoNT toxinotypes or subtypes, provides the basis for innovative BoNT-based therapeutics and research tools. This expanding BoNT superfamily forms the foundation for new toxins candidates in a wider range of therapeutic options.
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10
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Sikorra S, Donald S, Elliott M, Schwede S, Coker SF, Kupinski AP, Tripathi V, Foster K, Beard M, Binz T. Engineering an Effective Human SNAP-23 Cleaving Botulinum Neurotoxin A Variant. Toxins (Basel) 2020; 12:toxins12120804. [PMID: 33352834 PMCID: PMC7766560 DOI: 10.3390/toxins12120804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 12/13/2022] Open
Abstract
Botulinum neurotoxin (BoNT) serotype A inhibits neurotransmitter release by cleaving SNAP-25 and represents an established pharmaceutical for treating medical conditions caused by hyperactivity of cholinergic nerves. Oversecretion from non-neuronal cells is often also the cause of diseases. Notably, excessive release of inflammatory messengers is thought to contribute to diseases such as chronic obstructive pulmonary disease, asthma, diabetes etc. The expansion of its application to these medical conditions is prevented because the major non-neuronal SNAP-25 isoform responsible for exocytosis, SNAP-23, is, in humans, virtually resistant to BoNT/A. Based on previous structural data and mutagenesis studies of SNAP-23 we optimized substrate binding pockets of the enzymatic domain for interaction with SNAP-23. Systematic mutagenesis and rational design yielded the mutations E148Y, K166F, S254A, and G305D, each of which individually increased the activity of LC/A against SNAP-23 between 3- to 23-fold. The assembled quadruple mutant showed approximately 2000-fold increased catalytic activity against human SNAP-23 in in vitro cleavage assays. A comparable increase in activity was recorded for the full-length BoNT/A quadruple mutant tested in cultivated primary neurons transduced with a fluorescently tagged-SNAP-23 encoding gene. Equipped with a suitable targeting domain this quadruple mutant promises to complete successfully tests in cells of the immune system.
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Affiliation(s)
- Stefan Sikorra
- Institut für Zellbiochemie, OE 4310, Medizinische Hochschule Hannover, 30623 Hannover, Germany; (S.S.); (S.S.)
| | - Sarah Donald
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Susan Schwede
- Institut für Zellbiochemie, OE 4310, Medizinische Hochschule Hannover, 30623 Hannover, Germany; (S.S.); (S.S.)
| | - Shu-Fen Coker
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Adam P. Kupinski
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Vineeta Tripathi
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Keith Foster
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK; (S.D.); (M.E.); (S.-F.C.); (A.P.K.); (V.T.); (K.F.)
- Correspondence: (M.B.); (T.B.); Tel.: +44(0)7850-910340 (M.B.); +49(0)511-532-2859 (T.B.)
| | - Thomas Binz
- Institut für Zellbiochemie, OE 4310, Medizinische Hochschule Hannover, 30623 Hannover, Germany; (S.S.); (S.S.)
- Correspondence: (M.B.); (T.B.); Tel.: +44(0)7850-910340 (M.B.); +49(0)511-532-2859 (T.B.)
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11
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Steward L, Brin MF, Brideau-Andersen A. Novel Native and Engineered Botulinum Neurotoxins. Handb Exp Pharmacol 2020; 263:63-89. [PMID: 32274579 DOI: 10.1007/164_2020_351] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Botulinum neurotoxins (BoNTs), produced by Clostridia and other bacteria, are the most potent toxins known. Their cleavage of the soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE) proteins in neurons prevents the release of neurotransmitters, thus resulting in the muscle paralysis that is characteristic of botulism. This mechanism of action has been exploited for a variety of therapeutic and cosmetic applications of BoNTs. This chapter provides an overview of the native BoNTs, including the classical serotypes and their clinical use, mosaic BoNTs, and novel BoNTs that have been recently identified in clostridial and non-clostridial strains. In addition, the modular structure of native BoNTs, which are composed of a light chain and a heavy chain, is amenable to a multitude of novel fusions and mutations using molecular biology techniques. These novel recombinant BoNTs have been used or are being developed to further characterize the biology of toxins, to assist in vaccine production, to serve as delivery vehicles to neurons, and to be utilized as novel therapeutics for both neuronal and non-neuronal cells.
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Affiliation(s)
| | - Mitchell F Brin
- Allergan plc, Irvine, CA, USA.,University of California, Irvine, CA, USA
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12
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Che Y, Siprashvili Z, Kovalski JR, Jiang T, Wozniak G, Elcavage L, Khavari PA. KRAS regulation by small non-coding RNAs and SNARE proteins. Nat Commun 2019; 10:5118. [PMID: 31712554 PMCID: PMC6848142 DOI: 10.1038/s41467-019-13106-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 10/13/2019] [Indexed: 12/30/2022] Open
Abstract
KRAS receives and relays signals at the plasma membrane (PM) where it transmits extracellular growth factor signals to downstream effectors. SNORD50A/B were recently found to bind KRAS and inhibit its tumorigenic action by unknown mechanisms. KRAS proximity protein labeling was therefore undertaken in SNORD50A/B wild-type and knockout cells, revealing that SNORD50A/B RNAs shape the composition of proteins proximal to KRAS, notably by inhibiting KRAS proximity to the SNARE vesicular transport proteins SNAP23, SNAP29, and VAMP3. To remain enriched on the PM, KRAS undergoes cycles of endocytosis, solubilization, and vesicular transport to the PM. Here we report that SNAREs are essential for the final step of this process, with KRAS localization to the PM facilitated by SNAREs but antagonized by SNORD50A/B. Antagonism between SNORD50A/B RNAs and specific SNARE proteins thus controls KRAS localization, signaling, and tumorigenesis, and disrupting SNARE-enabled KRAS function represents a potential therapeutic opportunity in KRAS-driven cancer.
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Affiliation(s)
- Yonglu Che
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
- Program in Cancer Biology, Stanford University, Stanford, CA, 94305, USA
| | - Zurab Siprashvili
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
- Program in Cancer Biology, Stanford University, Stanford, CA, 94305, USA
| | - Joanna R Kovalski
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
- Program in Cancer Biology, Stanford University, Stanford, CA, 94305, USA
| | - Tiffany Jiang
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
| | - Glenn Wozniak
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
| | - Lara Elcavage
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA
| | - Paul A Khavari
- Program in Epithelial Biology, Stanford University, Stanford, CA, 94305, USA.
- Program in Cancer Biology, Stanford University, Stanford, CA, 94305, USA.
- VA Palo Alto Healthcare System, Palo Alto, CA, 94304, USA.
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13
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Abstract
Botulinum neurotoxins (BoNTs) and tetanus neurotoxin (TeNT) are the most potent toxins known and cause botulism and tetanus, respectively. BoNTs are also widely utilized as therapeutic toxins. They contain three functional domains responsible for receptor-binding, membrane translocation, and proteolytic cleavage of host proteins required for synaptic vesicle exocytosis. These toxins also have distinct features: BoNTs exist within a progenitor toxin complex (PTC), which protects the toxin and facilitates its absorption in the gastrointestinal tract, whereas TeNT is uniquely transported retrogradely within motor neurons. Our increasing knowledge of these toxins has allowed the development of engineered toxins for medical uses. The discovery of new BoNTs and BoNT-like proteins provides additional tools to understand the evolution of the toxins and to engineer toxin-based therapeutics. This review summarizes the progress on our understanding of BoNTs and TeNT, focusing on the PTC, receptor recognition, new BoNT-like toxins, and therapeutic toxin engineering.
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Affiliation(s)
- Min Dong
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden;
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; .,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
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14
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Lam KH, Sikorra S, Weisemann J, Maatsch H, Perry K, Rummel A, Binz T, Jin R. Structural and biochemical characterization of the protease domain of the mosaic botulinum neurotoxin type HA. Pathog Dis 2018; 76:4982781. [PMID: 29688327 DOI: 10.1093/femspd/fty044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/20/2018] [Indexed: 11/13/2022] Open
Abstract
The extreme toxicity of botulinum neurotoxins (BoNTs) relies on their specific cleavage of SNARE proteins, which eventually leads to muscle paralysis. One newly identified mosaic toxin, BoNT/HA (aka H or FA), cleaves VAMP-2 at a unique position between residues L54 and E55, but the molecular basis underlying VAMP-2 recognition of BoNT/HA remains poorly characterized. Here, we report a ∼2.09 Å resolution crystal structure of the light chain protease domain of BoNT/HA (LC/HA). Structural comparison between LC/HA and LC of BoNT/F1 (LC/F1) reveals distinctive hydrophobic and electrostatic features near the active sites, which may explain their different VAMP-2 cleavage sites. When compared to BoNT/F5 that cleaves VAMP-2 at the same site as BoNT/HA, LC/HA displays higher affinity for VAMP-2, which could be caused by their different surface charge properties surrounding a VAMP-2 exosite-binding cleft. Furthermore, systematic mutagenesis studies on VAMP-2 and structural modeling demonstrate that residues R47 to K59 spanning the cleavage site in VAMP-2 may adopt a novel extended conformation when interacting with LC/HA and LC/F5. Taken together, our structure provides new insights into substrate recognition of BoNT/HA and paves the way for rational design of small molecule or peptide inhibitors against LC/HA.
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Affiliation(s)
- Kwok-Ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697 USA
| | - Stefan Sikorra
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Jasmin Weisemann
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Hannah Maatsch
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Thomas Binz
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697 USA
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15
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Torgeman A, Schwartz A, Diamant E, Baruchi T, Dor E, Ben David A, Pass A, Barnea A, Tal A, Rosner A, Rosen O, Zichel R. Studying the differential efficacy of postsymptom antitoxin treatment in type A versus type B botulism using a rabbit spirometry model. Dis Model Mech 2018; 11:dmm.035089. [PMID: 30115749 PMCID: PMC6177009 DOI: 10.1242/dmm.035089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/30/2018] [Indexed: 11/20/2022] Open
Abstract
Botulinum neurotoxin (BoNT) serotypes A, B and E are responsible for most cases of human botulism. The only approved therapy for botulism is antitoxin treatment administered to patients after symptom onset. However, a recent meta-analysis of antitoxin efficacy in human botulism cases over the past century concluded that a statistically significant reduction in mortality is associated with the use of type E and type A antitoxin, but not with type B antitoxin. Animal models could be highly valuable in studying postsymptom antitoxin efficacy (PSAE). However, the few attempts to evaluate PSAE in animals relied on subjective observations and showed ∼50% protection. Recently, we developed a novel spirometry model for the quantitative evaluation of PSAE in rabbits and used it to demonstrate full protection against BoNT/E. In the current study, a comparative evaluation of PSAE in botulism types A and B was conducted using this quantitative respiratory model. A lethal dose of each toxin induced a comparable course of disease both in terms of time to symptoms (TTS, 41.9±1.3 and 40.6±1.1 h, respectively) and of time to death (TTD, 71.3±3.1 and 66.3±1.7 h, respectively). However, in accordance with the differential serotypic PSAE observed in humans, postsymptom antitoxin treatment was fully effective only in BoNT/A-intoxicated rabbits. This serotypic divergence was reflected by a positive and statistically significant correlation between TTS and TTD in BoNT/A-intoxicated rabbits (r=0.91, P=0.0006), but not in those intoxicated with BoNT/B (r=0.06, P=0.88). The rabbit spirometry system might be useful in the evaluation toolkit of botulism therapeutics, including those under development and intended to act when antitoxin is no longer effective. Summary: Here, we used a quantitative rabbit respiratory model to study the human-related, differential antitoxin efficacy observed in type A and type B botulism.
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Affiliation(s)
- Amram Torgeman
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Arieh Schwartz
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Eran Diamant
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Tzadok Baruchi
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Eyal Dor
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Alon Ben David
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Avi Pass
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Ada Barnea
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Arnon Tal
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Amir Rosner
- The Veterinary Center for Pre-clinical Research, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Osnat Rosen
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel
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16
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Fonfria E, Elliott M, Beard M, Chaddock JA, Krupp J. Engineering Botulinum Toxins to Improve and Expand Targeting and SNARE Cleavage Activity. Toxins (Basel) 2018; 10:toxins10070278. [PMID: 29973505 PMCID: PMC6071219 DOI: 10.3390/toxins10070278] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 12/14/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are highly successful protein therapeutics. Over 40 naturally occurring BoNTs have been described thus far and, of those, only 2 are commercially available for clinical use. Different members of the BoNT family present different biological properties but share a similar multi-domain structure at the molecular level. In nature, BoNTs are encoded by DNA in producing clostridial bacteria and, as such, are amenable to recombinant production through insertion of the coding DNA into other bacterial species. This, in turn, creates possibilities for protein engineering. Here, we review the production of BoNTs by the natural host and also recombinant production approaches utilised in the field. Applications of recombinant BoNT-production include the generation of BoNT-derived domain fragments, the creation of novel BoNTs with improved performance and enhanced therapeutic potential, as well as the advancement of BoNT vaccines. In this article, we discuss site directed mutagenesis, used to affect the biological properties of BoNTs, including approaches to alter their binding to neurons and to alter the specificity and kinetics of substrate cleavage. We also discuss the target secretion inhibitor (TSI) platform, in which the neuronal binding domain of BoNTs is substituted with an alternative cellular ligand to re-target the toxins to non-neuronal systems. Understanding and harnessing the potential of the biological diversity of natural BoNTs, together with the ability to engineer novel mutations and further changes to the protein structure, will provide the basis for increasing the scope of future BoNT-based therapeutics.
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Affiliation(s)
- Elena Fonfria
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - John A Chaddock
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Johannes Krupp
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
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17
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Light Chain Diversity among the Botulinum Neurotoxins. Toxins (Basel) 2018; 10:toxins10070268. [PMID: 30004421 PMCID: PMC6070880 DOI: 10.3390/toxins10070268] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 12/30/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are produced by several species of clostridium. There are seven immunologically unique BoNT serotypes (A⁻G). The Centers for Disease Control classifies BoNTs as 'Category A' select agents and are the most lethal protein toxins for humans. Recently, BoNT-like proteins have also been identified in several non-clostridia. BoNTs are di-chain proteins comprised of an N-terminal zinc metalloprotease Light Chain (LC) and a C-terminal Heavy Chain (HC) which includes the translocation and receptor binding domains. The two chains are held together by a disulfide bond. The LC cleaves Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). The cleavage of SNAREs inhibits the fusion of synaptic vesicles to the cell membrane and the subsequent release of acetylcholine, which results in flaccid paralysis. The LC controls the catalytic properties and the duration of BoNT action. This review discusses the mechanism for LC catalysis, LC translocation, and the basis for the duration of LC action. Understanding these properties of the LC may expand the applications of BoNT as human therapies.
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18
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Tehran DA, Pirazzini M. Novel Botulinum Neurotoxins: Exploring Underneath the Iceberg Tip. Toxins (Basel) 2018; 10:toxins10050190. [PMID: 29748471 PMCID: PMC5983246 DOI: 10.3390/toxins10050190] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/05/2018] [Accepted: 05/08/2018] [Indexed: 12/26/2022] Open
Abstract
Botulinum neurotoxins (BoNTs), the etiological agents of botulism, are the deadliest toxins known to humans. Yet, thanks to their biological and toxicological features, BoNTs have become sophisticated tools to study neuronal physiology and valuable therapeutics for an increasing number of human disorders. BoNTs are produced by multiple bacteria of the genus Clostridium and, on the basis of their different immunological properties, were classified as seven distinct types of toxin. BoNT classification remained stagnant for the last 50 years until, via bioinformatics and high-throughput sequencing techniques, dozens of BoNT variants, novel serotypes as well as BoNT-like toxins within non-clostridial species have been discovered. Here, we discuss how the now “booming field” of botulinum neurotoxin may shed light on their evolutionary origin and open exciting avenues for future therapeutic applications.
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Affiliation(s)
- Domenico Azarnia Tehran
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy.
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy.
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19
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Saraiva RG, Fang J, Kang S, Angleró-Rodríguez YI, Dong Y, Dimopoulos G. Aminopeptidase secreted by Chromobacterium sp. Panama inhibits dengue virus infection by degrading the E protein. PLoS Negl Trop Dis 2018; 12:e0006443. [PMID: 29694346 PMCID: PMC5937796 DOI: 10.1371/journal.pntd.0006443] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 05/07/2018] [Accepted: 04/10/2018] [Indexed: 12/14/2022] Open
Abstract
Dengue virus (DENV) is the most prevalent and burdensome arbovirus transmitted by Aedes mosquitoes, against which there is only a limited licensed vaccine and no approved drug treatment. A Chromobacterium species, C. sp. Panama, isolated from the midgut of A. aegypti is able to inhibit DENV replication within the mosquito and in vitro. Here we show that C. sp. Panama mediates its anti-DENV activity through secreted factors that are proteinous in nature. The inhibitory effect occurs prior to virus attachment to cells, and is attributed to a factor that destabilizes the virion by promoting the degradation of the viral envelope protein. Bioassay-guided fractionation, coupled with mass spectrometry, allowed for the identification of a C. sp. Panama-secreted neutral protease and an aminopeptidase that are co-expressed and appear to act synergistically to degrade the viral envelope (E) protein and thus prevent viral attachment and subsequent infection of cells. This is the first study characterizing the anti-DENV activity of a common soil and mosquito-associated bacterium, thereby contributing towards understanding how such bacteria may limit disease transmission, and providing new tools for dengue prevention and therapeutics.
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Affiliation(s)
- Raúl G. Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Jingru Fang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Seokyoung Kang
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Yesseinia I. Angleró-Rodríguez
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Yuemei Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
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20
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Yang Y, Kong B, Jung Y, Park JB, Oh JM, Hwang J, Cho JY, Kweon DH. Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation. Front Immunol 2018; 9:725. [PMID: 29696021 PMCID: PMC5904360 DOI: 10.3389/fimmu.2018.00725] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 03/23/2018] [Indexed: 01/09/2023] Open
Abstract
Vesicle-associated V-soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans-SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.
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Affiliation(s)
- Yoosoo Yang
- Biomedical Research Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Division for Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Daejeon, South Korea
| | - Byoungjae Kong
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, South Korea
| | - Younghoon Jung
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, South Korea
| | - Joon-Bum Park
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, South Korea
| | - Jung-Mi Oh
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea
| | - Jaesung Hwang
- Department of Genetic Engineering, College of Life Science, Kyung Hee University, Yongin, South Korea
| | - Jae Youl Cho
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, South Korea
| | - Dae-Hyuk Kweon
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, South Korea
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21
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Discovery of novel bacterial toxins by genomics and computational biology. Toxicon 2018; 147:2-12. [PMID: 29438679 DOI: 10.1016/j.toxicon.2018.02.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 12/23/2017] [Accepted: 02/07/2018] [Indexed: 12/13/2022]
Abstract
Hundreds and hundreds of bacterial protein toxins are presently known. Traditionally, toxin identification begins with pathological studies of bacterial infectious disease. Following identification and cultivation of a bacterial pathogen, the protein toxin is purified from the culture medium and its pathogenic activity is studied using the methods of biochemistry and structural biology, cell biology, tissue and organ biology, and appropriate animal models, supplemented by bioimaging techniques. The ongoing and explosive development of high-throughput DNA sequencing and bioinformatic approaches have set in motion a revolution in many fields of biology, including microbiology. One consequence is that genes encoding novel bacterial toxins can be identified by bioinformatic and computational methods based on previous knowledge accumulated from studies of the biology and pathology of thousands of known bacterial protein toxins. Starting from the paradigmatic cases of diphtheria toxin, tetanus and botulinum neurotoxins, this review discusses traditional experimental approaches as well as bioinformatics and genomics-driven approaches that facilitate the discovery of novel bacterial toxins. We discuss recent work on the identification of novel botulinum-like toxins from genera such as Weissella, Chryseobacterium, and Enteroccocus, and the implications of these computationally identified toxins in the field. Finally, we discuss the promise of metagenomics in the discovery of novel toxins and their ecological niches, and present data suggesting the existence of uncharacterized, botulinum-like toxin genes in insect gut metagenomes.
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22
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Gustafsson R, Berntsson RPA, Martínez-Carranza M, El Tekle G, Odegrip R, Johnson EA, Stenmark P. Crystal structures of OrfX2 and P47 from a Botulinum neurotoxin OrfX-type gene cluster. FEBS Lett 2017; 591:3781-3792. [PMID: 29067689 DOI: 10.1002/1873-3468.12889] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 11/08/2022]
Abstract
Botulinum neurotoxins are highly toxic substances and are all encoded together with one of two alternative gene clusters, the HA or the OrfX gene cluster. Very little is known about the function and structure of the proteins encoded in the OrfX gene cluster, which in addition to the toxin contains five proteins (OrfX1, OrfX2, OrfX3, P47, and NTNH). We here present the structures of OrfX2 and P47, solved to 2.1 and 1.8 Å, respectively. We show that they belong to the TULIP protein superfamily, which are often involved in lipid binding. OrfX1 and OrfX2 were both found to bind phosphatidylinositol lipids.
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Affiliation(s)
- Robert Gustafsson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden.,Department of Medical Biochemistry and Biophysics, Umeå University, Sweden
| | | | - Geniver El Tekle
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Richard Odegrip
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
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23
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Abstract
Regulated exocytosis can be split into a sequence of steps ending with the formation and the dilation of a fusion pore, a neck-like connection between the vesicle and the plasma membrane. Each of these steps is precisely controlled to achieve the optimal spatial and temporal profile of the release of signalling molecules. At the level of the fusion pore, tuning of the exocytosis can be achieved by preventing its formation, by stabilizing the unproductive narrow fusion pore, by altering the speed of fusion pore expansion and by completely closing the fusion pore. The molecular structure and dynamics of fusion pores have become a major focus of cell research, especially as a promising target for therapeutic strategies. Electrophysiological, optical and electrochemical methods have been used extensively to illuminate how cells regulate secretion at the level of a single fusion pore. Here, we describe recent advances in the structure and mechanisms of the initial fusion pore formation and the progress in therapeutic strategies with the focus on exocytosis.
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24
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Tao L, Peng L, Berntsson RPA, Liu SM, Park S, Yu F, Boone C, Palan S, Beard M, Chabrier PE, Stenmark P, Krupp J, Dong M. Engineered botulinum neurotoxin B with improved efficacy for targeting human receptors. Nat Commun 2017; 8:53. [PMID: 28674381 PMCID: PMC5495808 DOI: 10.1038/s41467-017-00064-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 04/26/2017] [Indexed: 11/25/2022] Open
Abstract
Botulinum neurotoxin B is a Food and Drug Administration-approved therapeutic toxin. However, it has lower binding affinity toward the human version of its major receptor, synaptotagmin II (h-Syt II), compared to mouse Syt II, because of a residue difference. Increasing the binding affinity to h-Syt II may improve botulinum neurotoxin B’s therapeutic efficacy and reduce adverse effects. Here we utilized the bacterial adenylate cyclase two-hybrid method and carried out a saturation mutagenesis screen in the Syt II-binding pocket of botulinum neurotoxin B. The screen identifies E1191 as a key residue: replacing it with M/C/V/Q enhances botulinum neurotoxin B binding to human synaptotagmin II. Adding S1199Y/W or W1178Q as a secondary mutation further increases binding affinity. Mutant botulinum neurotoxin B containing E1191M/S1199Y exhibits ~11-fold higher efficacy in blocking neurotransmission than wild-type botulinum neurotoxin B in neurons expressing human synaptotagmin II, demonstrating that enhancing receptor binding increases the overall efficacy at functional levels. The engineered botulinum neurotoxin B provides a platform to develop therapeutic toxins with improved efficacy. Humans are less sensitive to the therapeutic effects of botulinum neurotoxin B (BoNT/B) than the animal models it is tested on due to differences between the human and the mouse receptors. Here, the authors engineer BoNT/B to improve its affinity to human receptors and enhance its therapeutic efficacy.
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Affiliation(s)
- Liang Tao
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Lisheng Peng
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.,Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 Tianhe Road, Guangzhou, Guangdong, 510630, China
| | - Ronnie P-A Berntsson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, SE-106 91, Sweden.,Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, SE-901 87, Sweden
| | | | - SunHyun Park
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.,Division of Predictive Toxicological Research, Predictive model Research Center, Korea Institute of Toxicology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, South Korea
| | - Feifan Yu
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | - Christopher Boone
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA
| | | | | | | | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, SE-106 91, Sweden.
| | - Johannes Krupp
- IPSEN Bioinnovation, Abingdon, OX14 4RY, UK. .,IPSEN Innovation, Les Ulis, 91940, France.
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology, Department of Surgery, Harvard Medical School, 300 Longwood Avenue, Boston, Massachusetts, 02115, USA.
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Pirazzini M, Rossetto O, Eleopra R, Montecucco C. Botulinum Neurotoxins: Biology, Pharmacology, and Toxicology. Pharmacol Rev 2017; 69:200-235. [PMID: 28356439 PMCID: PMC5394922 DOI: 10.1124/pr.116.012658] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The study of botulinum neurotoxins (BoNT) is rapidly progressing in many aspects.
Novel BoNTs are being discovered owing to next generation sequencing, but their
biologic and pharmacological properties remain largely unknown. The molecular
structure of the large protein complexes that the toxin forms with accessory
proteins, which are included in some BoNT type A1 and B1 pharmacological
preparations, have been determined. By far the largest effort has been dedicated to
the testing and validation of BoNTs as therapeutic agents in an ever increasing
number of applications, including pain therapy. BoNT type A1 has been also exploited
in a variety of cosmetic treatments, alone or in combination with other agents, and
this specific market has reached the size of the one dedicated to the treatment of
medical syndromes. The pharmacological properties and mode of action of BoNTs have
shed light on general principles of neuronal transport and protein-protein
interactions and are stimulating basic science studies. Moreover, the wide array of
BoNTs discovered and to be discovered and the production of recombinant BoNTs endowed
with specific properties suggest novel uses in therapeutics with increasing
disease/symptom specifity. These recent developments are reviewed here to provide an
updated picture of the biologic mechanism of action of BoNTs, of their increasing use
in pharmacology and in cosmetics, and of their toxicology.
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Affiliation(s)
- Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Roberto Eleopra
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Italy (M.P., O.R., C.M.); Neurologic Department, University-Hospital S. Maria della Misericordia, Udine, Italy (R.E.); and Consiglio Nazionale delle Ricerche, Institute of Neuroscience, University of Padova, Italy (C.M.)
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Lutz S, Williams E, Muthu P. Engineering Therapeutic Enzymes. DIRECTED ENZYME EVOLUTION: ADVANCES AND APPLICATIONS 2017:17-67. [DOI: 10.1007/978-3-319-50413-1_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Fan L, Chen Z, Fu W, Xu N, Liu J, Lu A, Li Z, Su S, Wu T, Ou A. Soluble N-ethylmaleimide-sensitive Factor Attachment Receptor (SNARE) Protein Involved in the Remission of Depression by Acupuncture in Rats. J Acupunct Meridian Stud 2016; 9:242-249. [PMID: 27776762 DOI: 10.1016/j.jams.2016.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 04/09/2016] [Accepted: 04/15/2016] [Indexed: 02/05/2023] Open
Abstract
This study aims to investigate the molecular mechanisms of acupuncture in the remission of depression. A depressive disorder model was induced by exposing Sprague-Dawley rats to chronic unpredictable stress. The rats were divided into five groups: healthy (blank group) and stressed rats (model group), and stressed rats treated with acupuncture (acupuncture group), riluzole (riluzole group), acupuncture combined with botulinum toxin A (BTX-A) injection (acupuncture+BTX-A group) or riluzole combined with BTX-A injection (riluzole+BTX-A group). Behavioral analysis showed significant differences in sucrose consumption, weight, and horizontal or vertical movements between the model and both the riluzole and acupuncture groups. No obvious differences between the riluzole+BTX-A and acupuncture+BTX-A groups were found. Moreover, no significance differences in glutamate content in the hippocampus were found among the riluzole+BTX-A, acupuncture+BTX-A and model groups (p>0.05). Western blots and reverse transcription polymerase chain reactions were employed to detect protein and mRNA expressions of VGLUT2, SNAP25, VAMP1, VAMP2, VAMP7, and syntaxin1; no obvious differences among the riluzole+BTX-A, acupuncture+BTX-A and model groups were found. These data suggest that soluble N-ethylmaleimide-sensitive factor attachment receptor proteins are involved in the remission of depression in rats treated with acupuncture.
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Affiliation(s)
- Ling Fan
- Department of Acupuncture and Moxibustion, Guangdong Provincial Hospital of TCM, Guangzhou, China; Postdoctoral Research Station of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhao Chen
- Division of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Wenbin Fu
- Department of Acupuncture and Moxibustion, Guangdong Provincial Hospital of TCM, Guangzhou, China.
| | - Nenggui Xu
- College of Acupuncture and Moxibustion, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jianhua Liu
- Department of Acupuncture and Moxibustion, Guangdong Provincial Hospital of TCM, Guangzhou, China
| | - Aiping Lu
- Department of Acupuncture and Moxibustion, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Ziping Li
- Department of Acupuncture and Moxibustion, Guangdong Provincial Hospital of TCM, Guangzhou, China
| | - Shengyong Su
- Department of Acupuncture and Moxibustion, The First Affiliated Hospital of Guangxi University of Chinese Medicine, Nanning, China
| | - Taixiang Wu
- Primary Registry of WHO ICTRP, Chinese Clinical Trial Registry, Chinese Evidence-based Medicine Center, Chinese Cochrane Center, West China Hospital, Sichuan University, Chengdu, China
| | - Aihua Ou
- Department of Epidemiology Center, Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
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TNFα induces co-trafficking of TRPV1/TRPA1 in VAMP1-containing vesicles to the plasmalemma via Munc18-1/syntaxin1/SNAP-25 mediated fusion. Sci Rep 2016; 6:21226. [PMID: 26888187 PMCID: PMC4758037 DOI: 10.1038/srep21226] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 09/16/2015] [Indexed: 11/08/2022] Open
Abstract
Transient receptor potential (TRP) A1 and V1 channels relay sensory signals, yet little is known about their transport to the plasmalemma during inflammation. Herein, TRPA1 and TRPV1 were found on vesicles containing calcitonin gene-related peptide (CGRP), accumulated at sites of exo- and endo-cytosis, and co-localised on fibres and cell bodies of cultured sensory neurons expressing both. A proinflammatory cytokine, TNFα, elevated their surface content, and both resided in close proximity, indicating co-trafficking. Syntaxin 1-interacting protein, Munc18-1, proved necessary for the response to TNFα, and for TRPV1-triggered CGRP release. TNFα-induced surface trafficking of TRPV1 and TRPA1 required a synaptic vesicle membrane protein VAMP1 (but not 2/3), which is essential for CGRP exocytosis from large dense-core vesicles. Inactivation of two proteins on the presynaptic plasma membrane, syntaxin-1 or SNAP-25, by botulinum neurotoxin (BoNT)/C1 or /A inhibited the TNFα-elevated delivery. Accordingly, enhancement by TNFα of Ca(2+) influx through the upregulated surface-expressed TRPV1 and TRPA1 channels was abolished by BoNT/A. Thus, in addition, the neurotoxins' known inhibition of the release of pain transmitters, their therapeutic potential is augmented by lowering the exocytotic delivery of transducing channels and the resultant hyper-sensitisation in inflammation.
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Current status and future directions of botulinum neurotoxins for targeting pain processing. Toxins (Basel) 2015; 7:4519-63. [PMID: 26556371 PMCID: PMC4663519 DOI: 10.3390/toxins7114519] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/29/2015] [Accepted: 10/19/2015] [Indexed: 12/20/2022] Open
Abstract
Current evidence suggests that botulinum neurotoxins (BoNTs) A1 and B1, given locally into peripheral tissues such as skin, muscles, and joints, alter nociceptive processing otherwise initiated by inflammation or nerve injury in animal models and humans. Recent data indicate that such locally delivered BoNTs exert not only local action on sensory afferent terminals but undergo transport to central afferent cell bodies (dorsal root ganglia) and spinal dorsal horn terminals, where they cleave SNAREs and block transmitter release. Increasing evidence supports the possibility of a trans-synaptic movement to alter postsynaptic function in neuronal and possibly non-neuronal (glial) cells. The vast majority of these studies have been conducted on BoNT/A1 and BoNT/B1, the only two pharmaceutically developed variants. However, now over 40 different subtypes of botulinum neurotoxins (BoNTs) have been identified. By combining our existing and rapidly growing understanding of BoNT/A1 and /B1 in altering nociceptive processing with explorations of the specific characteristics of the various toxins from this family, we may be able to discover or design novel, effective, and long-lasting pain therapeutics. This review will focus on our current understanding of the molecular mechanisms whereby BoNTs alter pain processing, and future directions in the development of these agents as pain therapeutics.
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Chen S, Barbieri JT. Solubility of the catalytic domains of Botulinum neurotoxin serotype E subtypes. Protein Expr Purif 2015; 118:18-24. [PMID: 26477500 DOI: 10.1016/j.pep.2015.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 09/10/2015] [Accepted: 10/09/2015] [Indexed: 10/22/2022]
Abstract
The Clostridium botulinum neurotoxins (BoNTs) are the most potent protein toxins known to humans. There are seven serotypes of the BoNTs (A-G), among which serotypes A, B, E and F are known to cause natural human intoxication. To date, eleven subtypes of LC/E, termed E1∼E11, have been identified. The LCs of BoNT/E were insoluble, prohibiting studies towards understanding the mechanisms of toxin action and substrate recognition. In this work, the molecular basis of insolubility of the recombinant LCs of two representative subtypes of BoNT/E, E1(Beluga) and E3 (Alaska), was determined. Hydrophobicity profile and structural modeling predicted a C-terminal candidate region responsible for the insolubility of LC/Es. Deletion of C-terminal 19 residues of LC/E(1-400) resulted in enhanced solubility, from 2 to ∼50% for LC/EAlaska and from 16 to ∼95% for LC/EBeluga. In addition, resides 230-236 were found to contribute to a different solubility level of LC/EAlaska when compared to LC/EBeluga. Substituting residues (230)TCI(232) in LC/EAlaska to the corresponding residues of (230)KYT(232) in LC/EBeluga enhanced the solubility of LC/EAlaska to a level approaching that of LC/EBeluga. Among these LC/Es and their derivatives, LC/EBeluga 1-400 was the most soluble and stable protein. Each LC/E derivative possessed similar catalytic activity, suggesting that the C-terminal region of LC/Es contributed to protein solubility, but not catalytic activity. In conclusion, this study generated a soluble and stable recombinant LC/E and provided insight into the structural components that govern the solubility and stability of the LCs of other BoNT serotypes and Tetanus toxin.
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Affiliation(s)
- Sheng Chen
- Shenzhen Key Lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shenzhen Research Institute, Shenzhen, PR China; State Key Lab of Chirosciences, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
| | - Joseph T Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
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Meng J, Wang J. Role of SNARE proteins in tumourigenesis and their potential as targets for novel anti-cancer therapeutics. Biochim Biophys Acta Rev Cancer 2015; 1856:1-12. [PMID: 25956199 DOI: 10.1016/j.bbcan.2015.04.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 04/24/2015] [Accepted: 04/28/2015] [Indexed: 12/22/2022]
Abstract
The function of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) in cellular trafficking, membrane fusion and vesicle release in synaptic nerve terminals is well characterised. Recent studies suggest that SNAREs are also important in the control of tumourigenesis through the regulation of multiple signalling and transportation pathways. The majority of published studies investigated the effects of knockdown/knockout or overexpression of particular SNAREs on the normal function of cells as well as their dysfunction in tumourigenesis promotion. SNAREs are involved in the regulation of cancer cell invasion, chemo-resistance, the transportation of autocrine and paracrine factors, autophagy, apoptosis and the phosphorylation of kinases essential for cancer cell biogenesis. This evidence highlights SNAREs as potential targets for novel cancer therapy. This is the first review to summarise the expression and role of SNAREs in cancer biology at the cellular level, their interaction with non-SNARE proteins and modulation of cellular signalling cascades. Finally, a strategy is proposed for developing novel anti-cancer therapeutics using targeted delivery of a SNARE-inactivating protease into malignant cells.
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Affiliation(s)
- Jianghui Meng
- Charles Institute of Dermatology, School of Medicine and Medical Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Jiafu Wang
- International Centre for Neurotherapeutics, Dublin City University, Glasnevin, Dublin 9, Ireland.
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SNAP23 is selectively expressed in airway secretory cells and mediates baseline and stimulated mucin secretion. Biosci Rep 2015; 35:BSR20150004. [PMID: 26182382 PMCID: PMC4613665 DOI: 10.1042/bsr20150004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/14/2015] [Indexed: 11/17/2022] Open
Abstract
Airway mucin secretion is important pathophysiologically and as a model of polarized epithelial regulated exocytosis. We find the trafficking protein, SNAP23 (23-kDa paralogue of synaptosome-associated protein of 25 kDa), selectively expressed in secretory cells compared with ciliated and basal cells of airway epithelium by immunohistochemistry and FACS, suggesting that SNAP23 functions in regulated but not constitutive epithelial secretion. Heterozygous SNAP23 deletant mutant mice show spontaneous accumulation of intracellular mucin, indicating a defect in baseline secretion. However mucins are released from perfused tracheas of mutant and wild-type (WT) mice at the same rate, suggesting that increased intracellular stores balance reduced release efficiency to yield a fully compensated baseline steady state. In contrast, acute stimulated release of intracellular mucin from mutant mice is impaired whether measured by a static imaging assay 5 min after exposure to the secretagogue ATP or by kinetic analysis of mucins released from perfused tracheas during the first 10 min of ATP exposure. Together, these data indicate that increased intracellular stores cannot fully compensate for the defect in release efficiency during intense stimulation. The lungs of mutant mice develop normally and clear bacteria and instilled polystyrene beads comparable to WT mice, consistent with these functions depending on baseline secretion that is fully compensated.
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Rossetto O, Pirazzini M, Montecucco C. Botulinum neurotoxins: genetic, structural and mechanistic insights. Nat Rev Microbiol 2014; 12:535-49. [PMID: 24975322 DOI: 10.1038/nrmicro3295] [Citation(s) in RCA: 378] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Botulinum neurotoxins (BoNTs) are produced by anaerobic bacteria of the genus Clostridium and cause a persistent paralysis of peripheral nerve terminals, which is known as botulism. Neurotoxigenic clostridia belong to six phylogenetically distinct groups and produce more than 40 different BoNT types, which inactivate neurotransmitter release owing to their metalloprotease activity. In this Review, we discuss recent studies that have improved our understanding of the genetics and structure of BoNT complexes. We also describe recent insights into the mechanisms of BoNT entry into the general circulation, neuronal binding, membrane translocation and neuroparalysis.
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Affiliation(s)
- Ornella Rossetto
- 1] Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. [2] National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. [3]
| | - Marco Pirazzini
- 1] Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. [2] National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. [3]
| | - Cesare Montecucco
- 1] Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy. [2] National Research Council Institute of Neuroscience, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
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Pantano S, Montecucco C. The blockade of the neurotransmitter release apparatus by botulinum neurotoxins. Cell Mol Life Sci 2014; 71:793-811. [PMID: 23749048 PMCID: PMC11113401 DOI: 10.1007/s00018-013-1380-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/15/2013] [Accepted: 05/16/2013] [Indexed: 12/22/2022]
Abstract
The high toxicity of the seven serotypes of botulinum neurotoxins (BoNT/A to G), together with their specificity and reversibility, includes them in the list A of potential bioterrorism weapons and, at the same time, among the therapeutics of choice for a variety of human syndromes. They invade nerve terminals and cleave specifically the three proteins which form the heterotrimeric SNAP REceptors (SNARE) complex that mediates neurotransmitter release. The BoNT-induced cleavage of the SNARE proteins explains by itself the paralysing activity of the BoNTs because the truncated proteins cannot form the SNARE complex. However, in the case of BoNT/A, the most widely used toxin in therapy, additional factors come into play as it only removes a few residues from the synaptosomal associate protein of 25 kDa C-terminus and this results in a long duration of action. To explain these facts and other experimental data, we present here a model for the assembly of the neuroexocytosis apparatus in which Synaptotagmin and Complexin first assist the zippering of the SNARE complex, and then stabilize and clamp an octameric radial assembly of the SNARE complexes.
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Affiliation(s)
- Sergio Pantano
- Institut Pasteur de Montevideo, Calle Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Institute of Neuroscience, National Research Council, Viale G. Colombo 3, 35121 Padua, Italy
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Arsenault J, Cuijpers SAG, Ferrari E, Niranjan D, Rust A, Leese C, O'Brien JA, Binz T, Davletov B. Botulinum protease-cleaved SNARE fragments induce cytotoxicity in neuroblastoma cells. J Neurochem 2014; 129:781-91. [PMID: 24372287 PMCID: PMC4063335 DOI: 10.1111/jnc.12645] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 12/11/2022]
Abstract
Soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs) are crucial for exocytosis, trafficking, and neurite outgrowth, where vesicular SNAREs are directed toward their partner target SNAREs: synaptosomal-associated protein of 25 kDa and syntaxin. SNARE proteins are normally membrane bound, but can be cleaved and released by botulinum neurotoxins. We found that botulinum proteases types C and D can easily be transduced into endocrine cells using DNA-transfection reagents. Following administration of the C and D proteases into normally refractory Neuro2A neuroblastoma cells, the SNARE proteins were cleaved with high efficiency within hours. Remarkably, botulinum protease exposures led to cytotoxicity evidenced by spectrophotometric assays and propidium iodide penetration into the nuclei. Direct delivery of SNARE fragments into the neuroblastoma cells reduced viability similar to botulinum proteases' application. We observed synergistic cytotoxic effects of the botulinum proteases, which may be explained by the release and interaction of soluble SNARE fragments. We show for the first time that previously observed cytotoxicity of botulinum neurotoxins/C in neurons could be achieved in cells of neuroendocrine origin with implications for medical uses of botulinum preparations.
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Boddul SV, Meng J, Dolly JO, Wang J. SNAP-23 and VAMP-3 contribute to the release of IL-6 and TNFα from a human synovial sarcoma cell line. FEBS J 2013; 281:750-65. [DOI: 10.1111/febs.12620] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/23/2022]
Affiliation(s)
- Sanjay V. Boddul
- International Centre for Neurotherapeutics; Dublin City University; Ireland
| | - Jianghui Meng
- International Centre for Neurotherapeutics; Dublin City University; Ireland
| | - James Oliver Dolly
- International Centre for Neurotherapeutics; Dublin City University; Ireland
| | - Jiafu Wang
- International Centre for Neurotherapeutics; Dublin City University; Ireland
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Ye W, Guo J, Chen S, Yang M. Nanoporous membrane based impedance sensors to detect the enzymatic activity of botulinum neurotoxin A. J Mater Chem B 2013; 1:6544-6550. [PMID: 32261332 DOI: 10.1039/c3tb21152e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Botulinum neurotoxins are among the most potent toxic bacterial proteins for humans and there is a great need to develop simple, rapid and sensitive methods for toxin detection and protease activity quantification in field deployment. In this paper, a nanoporous membrane based impedance sensor was developed to monitor the activity of the BoNT serotype A light chain protease (LcA). Synaptosomal-associated protein 25 (SNAP-25) was first immobilized inside nanopore walls via silane linkers. BoNT LcA was then injected over the nanoporous membrane substrate sensor and specifically cleaved SNAP-25. The cleavage activity could be monitored by measuring impedance signals across nanoporous membranes which represented the nanopore blockage degree. This initial device could achieve a 500 pM LcA detection limit within 25 minutes.
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Affiliation(s)
- Weiwei Ye
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China.
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Masuyer G, Chaddock JA, Foster KA, Acharya KR. Engineered botulinum neurotoxins as new therapeutics. Annu Rev Pharmacol Toxicol 2013; 54:27-51. [PMID: 24016211 DOI: 10.1146/annurev-pharmtox-011613-135935] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Botulinum neurotoxins (BoNTs) cause flaccid paralysis by inhibiting neurotransmission at cholinergic nerve terminals. Each BoNT consists of three domains that are essential for toxicity: the binding domain, the translocation domain, and the catalytic light-chain domain. BoNT modular architecture is associated with a multistep mechanism that culminates in the intracellular proteolysis of SNARE (soluble N-ethylmaleimide-sensitive-fusion-protein attachment protein receptor) proteins, which prevents synaptic vesicle exocytosis. As the most toxic proteins known, BoNTs have been extensively studied and are used as pharmaceutical agents to treat an increasing variety of disorders. This review summarizes the level of sophistication reached in BoNT engineering and highlights the diversity of approaches taken to utilize the modularity of the toxin. Improved efficiency and applicability have been achieved by direct mutagenesis and interserotype domain rearrangement. The scope of BoNT activity has been extended to nonneuronal cells and offers the basis for novel biomolecules in the treatment of secretion disorders.
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Affiliation(s)
- Geoffrey Masuyer
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom;
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The rat Digit Abduction Score (DAS) assay: a physiological model for assessing botulinum neurotoxin-induced skeletal muscle paralysis. Toxicon 2013; 71:18-24. [PMID: 23707612 DOI: 10.1016/j.toxicon.2013.05.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/08/2013] [Indexed: 11/22/2022]
Abstract
Botulinum neurotoxins (BoNT) are approved for a number of therapeutic indications, including blepharospasm, cervical dystonia and hyperhidrosis, and have also shown efficacy in a variety of pain disorders. The potency of any given BoNT preparation can be routinely assessed by using the Digit Abduction Score (DAS) assay, which measures the local muscle weakening efficacy of BoNT following injection into mouse hindlimb muscle. While most studies have employed mice to assess BoNT efficacy in the DAS, few have utilized rats. In this study, we applied the DAS assay to a rat model and compared the potency of IM-BOTOX(®) (onabotulinumtoxinA) injections between two separate hind limb muscles, gastrocnemius and tibialis anterior (TA). The results demonstrated that the DAS assay can be performed on rats with similar criteria and parameters as for mice. Moreover in the rat, BoNT can be injected into either the gastrocnemius or TA muscle to elicit similar DAS scoring responses. Interestingly, onabotulinumtoxinA potency in the rat DAS was ∼3-fold higher following TA injections than gastrocnemius injections. Additionally, our data showed that the durational kinetics of onabotulinumtoxinA in the rat DAS are approximately twice as long as in the mouse DAS. These results position the rat DAS as a more flexible model for examining the mechanisms of BoNT diffusion and muscle paralysis, while mouse DAS can be used for physiological screening of BoNT because of the potential for higher throughput. Overall, these data confirm the utility of the DAS assay for characterizing the physiological potency of BoNT and related compounds.
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Arsenault J, Ferrari E, Niranjan D, Cuijpers SAG, Gu C, Vallis Y, O'Brien J, Davletov B. Stapling of the botulinum type A protease to growth factors and neuropeptides allows selective targeting of neuroendocrine cells. J Neurochem 2013; 126:223-33. [PMID: 23638840 PMCID: PMC3758956 DOI: 10.1111/jnc.12284] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 04/16/2013] [Accepted: 04/24/2013] [Indexed: 01/12/2023]
Abstract
Precise cellular targeting of macromolecular cargos has important biotechnological and medical implications. Using a recently established ‘protein stapling’ method, we linked the proteolytic domain of botulinum neurotoxin type A (BoNT/A) to a selection of ligands to target neuroendocrine tumor cells. The botulinum proteolytic domain was chosen because of its well-known potency to block the release of neurotransmitters and hormones. Among nine tested stapled ligands, the epidermal growth factor was able to deliver the botulinum enzyme into pheochromocytoma PC12 and insulinoma Min6 cells; ciliary neurotrophic factor was effective on neuroblastoma SH-SY5Y and Neuro2A cells, whereas corticotropin-releasing hormone was active on pituitary AtT-20 cells and the two neuroblastoma cell lines. In neuronal cultures, the epidermal growth factor- and ciliary neurotrophic factor-directed botulinum enzyme targeted distinct subsets of neurons whereas the whole native neurotoxin targeted the cortical neurons indiscriminately. At nanomolar concentrations, the retargeted botulinum molecules were able to inhibit stimulated release of hormones from tested cell lines suggesting their application for treatments of neuroendocrine disorders.
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Affiliation(s)
- Jason Arsenault
- MRC Laboratory of Molecular Biology, Neurobiology, Cambridge, UK
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41
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Patent Highlights. Pharm Pat Anal 2012. [DOI: 10.4155/ppa.12.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Snapshot of recent key developments in the patent literature of relevance to the advancement of pharmaceutical and medical R&D
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Chen S. Clinical uses of botulinum neurotoxins: current indications, limitations and future developments. Toxins (Basel) 2012; 4:913-39. [PMID: 23162705 PMCID: PMC3496996 DOI: 10.3390/toxins4100913] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/09/2012] [Accepted: 10/12/2012] [Indexed: 01/16/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) cause flaccid paralysis by interfering with vesicle fusion and neurotransmitter release in the neuronal cells. BoNTs are the most widely used therapeutic proteins. BoNT/A was approved by the U.S. FDA to treat strabismus, blepharospam, and hemificial spasm as early as 1989 and then for treatment of cervical dystonia, glabellar facial lines, axillary hyperhidrosis, chronic migraine and for cosmetic use. Due to its high efficacy, longevity of action and satisfactory safety profile, it has been used empirically in a variety of ophthalmological, gastrointestinal, urological, orthopedic, dermatological, secretory, and painful disorders. Currently available BoNT therapies are limited to neuronal indications with the requirement of periodic injections resulting in immune-resistance for some indications. Recent understanding of the structure-function relationship of BoNTs prompted the engineering of novel BoNTs to extend therapeutic interventions in non-neuronal systems and to overcome the immune-resistance issue. Much research still needs to be done to improve and extend the medical uses of BoNTs.
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Affiliation(s)
- Sheng Chen
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
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Davletov B, Ferrari E, Ushkaryov Y. Presynaptic neurotoxins: an expanding array of natural and modified molecules. Cell Calcium 2012; 52:234-40. [PMID: 22658826 DOI: 10.1016/j.ceca.2012.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 05/04/2012] [Accepted: 05/13/2012] [Indexed: 11/15/2022]
Abstract
The process of neurotransmitter release from nerve terminals is a target for a wide array of presynaptic toxins produced by various species, from humble bacteria to arthropods to vertebrate animals. Unlike other toxins, most presynaptic neurotoxins do not kill cells but simply inhibit or activate synaptic transmission. In this review, we describe two types of presynaptic neurotoxins: clostridial toxins and latrotoxins, which are, respectively, the most potent blockers and stimulators of neurotransmitter release. These toxins have been instrumental in defining presynaptic functions and are now widely used in research and medicine. Here, we would like to analyse the diversity of these toxins and demonstrate how the knowledge of their structures and mechanisms of action can help us to design better tools for research and medical applications. We will look at natural and synthetic variations of these exquisite molecular machines, highlighting recent advances in our understanding of presynaptic toxins and questions that remain to be answered. If we can decipher how a given biomolecule is modified by nature to target different species, we will be able to design new variants that carry only desired characteristics to achieve specific therapeutic, agricultural or research goals. Indeed, a number of research groups have already initiated a quest to harness the power of natural toxins with the aim of making them more specifically targeted and safer for future research and medical applications.
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Affiliation(s)
- Bazbek Davletov
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.
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44
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Transforming the Domain Structure of Botulinum Neurotoxins into Novel Therapeutics. Curr Top Microbiol Immunol 2012. [DOI: 10.1007/978-3-662-45790-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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45
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Stancombe PR, Masuyer G, Birch-Machin I, Beard M, Foster KA, Chaddock JA, Acharya KR. Engineering botulinum neurotoxin domains for activation by toxin light chain. FEBS J 2011; 279:515-23. [PMID: 22141396 DOI: 10.1111/j.1742-4658.2011.08444.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Targeted secretion inhibitors (TSI) are a new class of biopharmaceuticals designed from a botulinum neurotoxin protein scaffold. The backbone consists of the 50-kDa endopeptidase light chain and translocation domain (N-terminal portion of the heavy chain), lacks neuronal toxicity, but retains the ability to target cytoplasmic soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. TSI are produced as single-chain proteins and then cleaved post-translationally to generate functional heterodimers. Precise proteolytic cleavage is essential to activate the protein to a dichain form. TSI are themselves highly specific proteases. We have exploited this activity to create self-activating enzymes by replacing the native proteolytic site with a substrate SNARE peptide for the TSI protease. We have also created cross-activating backbones. By replacing the proteolytic activation site in one backbone with the substrate SNARE peptide for another serotype, controlled activation is achieved. SNARE peptides encompassing the whole of the coiled-coil region enabled complete activation and assembly of the dichain backbone. These engineered TSI backbones are capable of translocating their enzymatic domains to target intracellular SNARE proteins. They are also investigative tools with which to further the understanding of endopeptidase activity of light chain in SNARE interactions.
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Abstract
The seven serotypes of Clostridium botulinum neurotoxins (A-G) are the deadliest poison known to humans. They share significant sequence homology and hence possess similar structure-function relationships. Botulinum neurotoxins (BoNT) act via a four-step mechanism, viz., binding and internalization to neuronal cells, translocation of the catalytic domain into the cytosol and finally cleavage of one of the three soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) causing blockage of neurotransmitter release leading to flaccid paralysis. Crystal structures of three holotoxins, BoNT/A, B and E, are available to date. Although the individual domains are remarkably similar, their domain organization is different. These structures have helped in correlating the structural and functional domains. This has led to the determination of structures of individual domains and combinations of them. Crystal structures of catalytic domains of all serotypes and several binding domains are now available. The catalytic domains are zinc endopeptidases and share significant sequence and structural homology. The active site architecture and the catalytic mechanism are similar although the binding mode of individual substrates may be different, dictating substrate specificity and peptide cleavage selectivity. Crystal structures of catalytic domains with substrate peptides provide clues to specificity and selectivity unique to BoNTs. Crystal structures of the receptor domain in complex with ganglioside or the protein receptor have provided information about the binding of botulinum neurotoxin to the neuronal cell. An overview of the structure-function relationship correlating the 3D structures with biochemical and biophysical data and how they can be used for structure-based drug discovery is presented here.
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Kroken AR, Karalewitz APA, Fu Z, Baldwin MR, Kim JJP, Barbieri JT. Unique ganglioside binding by botulinum neurotoxins C and D-SA. FEBS J 2011; 278:4486-96. [PMID: 21554541 DOI: 10.1111/j.1742-4658.2011.08166.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The botulinum neurotoxins (BoNTs) are the most potent protein toxins for humans. There are seven serotypes of BoNTs (A-G), based on a lack of cross-antiserum neutralization. The BoNT/C and BoNT/D serotypes include mosaic toxins that are organized as D-C and C-D toxins. One BoNT D-C mosaic toxin, BoNT/D-South Africa (BoNT/D-SA), was not fully neutralized by immunization with a vaccine composed of either prototype BoNT/C-Stockholm or BoNT/D-1873. Whereas several BoNT serotypes utilize dual receptors (gangliosides and proteins) to bind to and enter neurons, the basis for BoNT/C and BoNT/D entry into neurons is less well understood. Recent studies solved the crystal structures of the receptor-binding domains of BoNT/C, BoNT/D, and BoNT/D-SA. Comparative structural analysis showed that BoNT/C, BoNT/D and BoNT/D-SA lacked components of the ganglioside-binding pocket that exists within other BoNT serotypes. With the use of structure-based alignments, biochemical analyses, and cell-binding approaches, BoNT/C and BoNT/D-SA have been shown to possess a unique ganglioside-binding domain, the ganglioside-binding loop. Defining how BoNTs enter host cells provides insights towards understanding the evolution and extending the potential therapeutic and immunological values of the BoNT serotypes.
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Affiliation(s)
- Abby R Kroken
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Abstract
Proteases are an expanding class of drugs that hold great promise. The U.S. FDA (Food and Drug Administration) has approved 12 protease therapies, and a number of next generation or completely new proteases are in clinical development. Although they are a well-recognized class of targets for inhibitors, proteases themselves have not typically been considered as a drug class despite their application in the clinic over the last several decades; initially as plasma fractions and later as purified products. Although the predominant use of proteases has been in treating cardiovascular disease, they are also emerging as useful agents in the treatment of sepsis, digestive disorders, inflammation, cystic fibrosis, retinal disorders, psoriasis and other diseases. In the present review, we outline the history of proteases as therapeutics, provide an overview of their current clinical application, and describe several approaches to improve and expand their clinical application. Undoubtedly, our ability to harness proteolysis for disease treatment will increase with our understanding of protease biology and the molecular mechanisms responsible. New technologies for rationally engineering proteases, as well as improved delivery options, will expand greatly the potential applications of these enzymes. The recognition that proteases are, in fact, an established class of safe and efficacious drugs will stimulate investigation of additional therapeutic applications for these enzymes. Proteases therefore have a bright future as a distinct therapeutic class with diverse clinical applications.
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Kiris E, Nuss JE, Burnett JC, Kota KP, Koh DC, Wanner LM, Torres-Melendez E, Gussio R, Tessarollo L, Bavari S. Embryonic stem cell-derived motoneurons provide a highly sensitive cell culture model for botulinum neurotoxin studies, with implications for high-throughput drug discovery. Stem Cell Res 2011; 6:195-205. [PMID: 21353660 PMCID: PMC3081902 DOI: 10.1016/j.scr.2011.01.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/05/2011] [Accepted: 01/10/2011] [Indexed: 11/21/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) inhibit cholinergic synaptic transmission by specifically cleaving proteins that are crucial for neurotransmitter exocytosis. Due to the lethality of these toxins, there are elevated concerns regarding their possible use as bioterrorism agents. Moreover, their widespread use for cosmetic purposes, and as medical treatments, has increased the potential risk of accidental overdosing and environmental exposure. Hence, there is an urgent need to develop novel modalities to counter BoNT intoxication. Mammalian motoneurons are the main target of BoNTs; however, due to the difficulty and poor efficiency of the procedures required to isolate the cells, they are not suitable for high-throughput drug screening assays. Here, we explored the suitability of embryonic stem (ES) cell-derived motoneurons as a renewable, reproducible, and physiologically relevant system for BoNT studies. We found that the sensitivity of ES-derived motoneurons to BoNT/A intoxication is comparable to that of primary mouse spinal motoneurons. Additionally, we demonstrated that several BoNT/A inhibitors protected SNAP-25, the BoNT/A substrate, in the ES-derived motoneuron system. Furthermore, this system is compatible with immunofluorescence-based high-throughput studies. These data suggest that ES-derived motoneurons provide a highly sensitive system that is amenable to large-scale screenings to rapidly identify and evaluate the biological efficacies of novel therapeutics.
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Affiliation(s)
- Erkan Kiris
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
- Neural Development Group, Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Jonathan E. Nuss
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - James C. Burnett
- SAIC Frederick, Inc., Target Structure-Based Drug Discovery Group (TSBDDG), National Cancer Institute at Frederick, MD 21702, USA
- TSBDDG, Information Technology Branch, Developmental Therapeutics Program, National Cancer Institute at Frederick, MD 2170, USA
| | - Krishna P. Kota
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Dawn C. Koh
- Neural Development Group, Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Laura M. Wanner
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Edna Torres-Melendez
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Rick Gussio
- TSBDDG, Information Technology Branch, Developmental Therapeutics Program, National Cancer Institute at Frederick, MD 2170, USA
| | - Lino Tessarollo
- Neural Development Group, Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Sina Bavari
- Department of Target Discovery and Experimental Microbiology, US Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
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Ferrari E, Maywood ES, Restani L, Caleo M, Pirazzini M, Rossetto O, Hastings MH, Niranjan D, Schiavo G, Davletov B. Re-assembled botulinum neurotoxin inhibits CNS functions without systemic toxicity. Toxins (Basel) 2011; 3:345-55. [PMID: 22069712 PMCID: PMC3202830 DOI: 10.3390/toxins3040345] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 03/18/2011] [Accepted: 03/23/2011] [Indexed: 11/23/2022] Open
Abstract
The therapeutic potential of botulinum neurotoxin type A (BoNT/A) has recently been widely recognized. BoNT/A acts to silence synaptic transmission via specific proteolytic cleavage of an essential neuronal protein, SNAP25. The advantages of BoNT/A-mediated synaptic silencing include very long duration, high potency and localized action. However, there is a fear of possible side-effects of BoNT/A due to its diffusible nature which may lead to neuromuscular blockade away from the injection site. We recently developed a “protein-stapling” technology which allows re-assembly of BoNT/A from two separate fragments. This technology allowed, for the first time, safe production of this popular neuronal silencing agent. Here we evaluated the re-assembled toxin in several CNS assays and assessed its systemic effects in an animal model. Our results show that the re-assembled toxin is potent in inhibiting CNS function at 1 nM concentration but surprisingly does not exhibit systemic toxicity after intraperitoneal injection even at 200 ng/kg dose. This shows that the re-assembled toxin represents a uniquely safe tool for neuroscience research and future medical applications.
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Affiliation(s)
- Enrico Ferrari
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; (E.F.); (E.S.M.); (M.H.H.); (D.N.)
| | - Elizabeth S. Maywood
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; (E.F.); (E.S.M.); (M.H.H.); (D.N.)
| | - Laura Restani
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, 56100 Pisa, Italy; (L.R.); (M.C.)
| | - Matteo Caleo
- Istituto di Neuroscienze, Consiglio Nazionale delle Ricerche, 56100 Pisa, Italy; (L.R.); (M.C.)
| | - Marco Pirazzini
- Dipartimento di Scienze Biomediche, Università di Padova, 35121 Padova, Italy; (M.P.); (O.R.)
| | - Ornella Rossetto
- Dipartimento di Scienze Biomediche, Università di Padova, 35121 Padova, Italy; (M.P.); (O.R.)
| | - Michael H. Hastings
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; (E.F.); (E.S.M.); (M.H.H.); (D.N.)
| | - Dhevahi Niranjan
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; (E.F.); (E.S.M.); (M.H.H.); (D.N.)
| | - Giampietro Schiavo
- Molecular NeuroPathoBiology Laboratory, Cancer Research UK London Research Institute, London WC2A 3LY, UK;
| | - Bazbek Davletov
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, UK; (E.F.); (E.S.M.); (M.H.H.); (D.N.)
- Author to whom correspondence should be addressed; ; Tel.: +44-1-223-402-009; Fax: +44-1-223-402-310
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