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Košenina S, Škerlová J, Zhang S, Dong M, Stenmark P. The cryo-EM structure of the BoNT/Wo-NTNH complex reveals two immunoglobulin-like domains. FEBS J 2024; 291:676-689. [PMID: 37746829 DOI: 10.1111/febs.16964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/07/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
The botulinum neurotoxin-like toxin from Weissella oryzae (BoNT/Wo) is one of the BoNT-like toxins recently identified outside of the Clostridium genus. We show that, like the canonical BoNTs, BoNT/Wo forms a complex with its non-toxic non-hemagglutinin (NTNH) partner, which in traditional BoNT serotypes protects the toxin from proteases and the acidic environment of the hosts' guts. We here report the cryo-EM structure of the 300 kDa BoNT/Wo-NTNH/Wo complex together with pH stability studies of the complex. The structure reveals molecular details of the toxin's interactions with its protective partner. The overall structural arrangement is similar to other reported BoNT-NTNH complexes, but NTNH/Wo uniquely contains two extra bacterial immunoglobulin-like (Big) domains on the C-terminus. Although the function of these Big domains is unknown, they are structurally most similar to bacterial proteins involved in adhesion to host cells. In addition, the BoNT/Wo protease domain contains an internal disulfide bond not seen in other BoNTs. Mass photometry analysis revealed that the BoNT/Wo-NTNH/Wo complex is stable under acidic conditions and may dissociate at neutral to basic pH. These findings established that BoNT/Wo-NTNH/Wo shares the general fold of canonical BoNT-NTNH complexes. The presence of unique structural features suggests that it may have an alternative mode of activation, translocation and recognition of host cells, raising interesting questions about the activity and the mechanism of action of BoNT/Wo as well as about its target environment, receptors and substrates.
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Affiliation(s)
- Sara Košenina
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Jana Škerlová
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
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2
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Gao L, Jin R. NTNH protein: more than a bodyguard for botulinum neurotoxins. FEBS J 2024; 291:672-675. [PMID: 38009421 PMCID: PMC10922118 DOI: 10.1111/febs.17004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/14/2023] [Indexed: 11/28/2023]
Abstract
As one of the most fatal substances, botulinum neurotoxins (BoNTs) have never acted solo to accomplish their formidable missions. Most notably, nontoxic nonhemagglutinin (NTNH), a protein co-secreted with BoNT by bacteria, plays critical roles to stabilize and protect BoNT by tightly associating with it to form the minimal progenitor toxin complex (M-PTC). A new cryo-EM structure of the M-PTC of a BoNT-like toxin from Weissella oryzae (BoNT/Wo) reveals similar assembly modes between M-PTC/Wo and that of other BoNTs, yet also reveals some unique structural features of NTNH/Wo. These findings shed new light on the potential versatile roles of NTNH during BoNT intoxication.
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Affiliation(s)
- Linfeng Gao
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
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3
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Zhou K, Luo W, Liu T, Ni Y, Qin Z. Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications. Toxins (Basel) 2022; 15:18. [PMID: 36668838 PMCID: PMC9865788 DOI: 10.3390/toxins15010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
Neurotoxins generally inhibit or promote the release of neurotransmitters or bind to receptors that are located in the pre- or post-synaptic membranes, thereby affecting physiological functions of synapses and affecting biological processes. With more and more research on the toxins of various origins, many neurotoxins are now widely used in clinical treatment and have demonstrated good therapeutic outcomes. This review summarizes the structural properties and potential pharmacological effects of neurotoxins acting on different components of the synapse, as well as their important clinical applications, thus could be a useful reference for researchers and clinicians in the study of neurotoxins.
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Affiliation(s)
- Kunming Zhou
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
| | - Weifeng Luo
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Tong Liu
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong 226019, China
| | - Yong Ni
- Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China
| | - Zhenghong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, College of Pharmaceutical Sciences, Suzhou Medical College of Soochow University, Suzhou 215123, China
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4
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Lam KH, Tremblay JM, Perry K, Ichtchenko K, Shoemaker CB, Jin R. Probing the structure and function of the protease domain of botulinum neurotoxins using single-domain antibodies. PLoS Pathog 2022; 18:e1010169. [PMID: 34990480 PMCID: PMC8769338 DOI: 10.1371/journal.ppat.1010169] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/19/2022] [Accepted: 12/04/2021] [Indexed: 12/03/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are among the deadliest of bacterial toxins. BoNT serotype A and B in particular pose the most serious threat to humans because of their high potency and persistence. To date, there is no effective treatment for late post-exposure therapy of botulism patients. Here, we aim to develop single-domain variable heavy-chain (VHH) antibodies targeting the protease domains (also known as the light chain, LC) of BoNT/A and BoNT/B as antidotes for post-intoxication treatments. Using a combination of X-ray crystallography and biochemical assays, we investigated the structures and inhibition mechanisms of a dozen unique VHHs that recognize four and three non-overlapping epitopes on the LC of BoNT/A and BoNT/B, respectively. We show that the VHHs that inhibit the LC activity occupy the extended substrate-recognition exosites or the cleavage pocket of LC/A or LC/B and thus block substrate binding. Notably, we identified several VHHs that recognize highly conserved epitopes across BoNT/A or BoNT/B subtypes, suggesting that these VHHs exhibit broad subtype efficacy. Further, we identify two novel conformations of the full-length LC/A, that could aid future development of inhibitors against BoNT/A. Our studies lay the foundation for structure-based engineering of protein- or peptide-based BoNT inhibitors with enhanced potencies and cross-subtypes properties.
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Affiliation(s)
- Kwok-ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Jacqueline M. Tremblay
- Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Kay Perry
- NE-CAT, Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Charles B. Shoemaker
- Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
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5
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Hong JY, Kim JH, Jin JE, Shin SH, Park KY. Practical Application of Novel Test Methods to Evaluate the Potency of Botulinum Toxin: A Comparison Analysis among Widely Used Products in Korea. Toxins (Basel) 2021; 13:toxins13120833. [PMID: 34941671 PMCID: PMC8707463 DOI: 10.3390/toxins13120833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022] Open
Abstract
The safe and effective dosing of botulinum neurotoxins (BoNTs) requires accurate and reliable methods to measure their potency. Several novel methods have been introduced over the past decade; however, only few studies have compared the potency of BoNT products with that of the LD50 and other alternative assays. Therefore, the objective of this study was to comparatively evaluate widely used BoNT products using various test methods. Four types of BoNTs (prabotulinumtoxin A, onabotulinumtoxin A, neubotulinumtoxin A, and letibotulinumtoxin A) were used in this study. The estimated potency was assessed using the LD50 assay, and the total BoNT type A protein levels were measured using the enzyme-linked immunosorbent assay (ELISA). The in vitro efficacy of the BoNTs was determined using fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) assays. The results showed differences in the total amount of BoNT protein and the cleavage activity of SNAP-25 within all types of BoNTs. The SPR study seemed to be useful for evaluating the potency by specifically measuring intact 19S neurotoxin, and these results provide new insights for assessing different BoNT products.
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Affiliation(s)
- Ji-Yeon Hong
- Department of Dermatology, Chungnam National University Sejong Hospital, Sejong 30099, Korea;
| | - Jong-Hee Kim
- NABOTA Research and Development Team, Daewoong Pharmaceuticals, Seoul 06973, Korea; (J.-H.K.); (J.-E.J.)
| | - Jung-Eun Jin
- NABOTA Research and Development Team, Daewoong Pharmaceuticals, Seoul 06973, Korea; (J.-H.K.); (J.-E.J.)
| | - Sun-Hye Shin
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 06973, Korea;
| | - Kui-Young Park
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 06973, Korea;
- Correspondence: ; Tel.: +82-2-6299-1544; Fax: +82-2-6299-1718
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6
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Choudhury S, Baker MR, Chatterjee S, Kumar H. Botulinum Toxin: An Update on Pharmacology and Newer Products in Development. Toxins (Basel) 2021; 13:58. [PMID: 33466571 PMCID: PMC7828686 DOI: 10.3390/toxins13010058] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/12/2022] Open
Abstract
Since its introduction as a treatment for strabismus, botulinum toxin (BoNT) has had a phenomenal journey and is now recommended as first-line treatment for focal dystonia, despite short-term clinical benefits and the risks of adverse effects. To cater for the high demand across various medical specialties, at least six US Food and Drug Administration (FDA)-approved formulations of BoNT are currently available for diverse labelled indications. The toxo-pharmacological properties of these formulations are not uniform and thus should not be used interchangeably. Synthetic BoNTs and BoNTs from non-clostridial sources are not far from clinical use. Moreover, the study of mutations in naturally occurring toxins has led to modulation in the toxo-pharmacokinetic properties of BoNTs, including the duration and potency. We present an overview of the toxo-pharmacology of conventional and novel BoNT preparations, including those awaiting imminent translation from the laboratory to the clinic.
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Affiliation(s)
- Supriyo Choudhury
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
| | - Mark R. Baker
- Departments of Neurology and Clinical Neurophysiology, Royal Victoria Infirmary, Queen Victoria Rd, Newcastle upon Tyne NE1 4LP, UK;
- Translational and Clinical Research Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Suparna Chatterjee
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
- Department of Pharmacology, Institute of Post Graduate Medical Education and Research, Kolkata 700020, India
| | - Hrishikesh Kumar
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
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7
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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8
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Rasetti-Escargueil C, Popoff MR. Antibodies and Vaccines against Botulinum Toxins: Available Measures and Novel Approaches. Toxins (Basel) 2019; 11:toxins11090528. [PMID: 31547338 PMCID: PMC6783819 DOI: 10.3390/toxins11090528] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/29/2019] [Accepted: 09/05/2019] [Indexed: 12/18/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is produced by the anaerobic, Gram-positive bacterium Clostridium botulinum. As one of the most poisonous toxins known and a potential bioterrosism agent, BoNT is characterized by a complex mode of action comprising: internalization, translocation and proteolytic cleavage of a substrate, which inhibits synaptic exocytotic transmitter release at neuro-muscular nerve endings leading to peripheral neuroparalysis of the skeletal and autonomic nervous systems. There are seven major serologically distinct toxinotypes (A-G) of BoNT which act on different substrates. Human botulism is generally caused by BoNT/A, B and E. Due to its extreme lethality and potential use as biological weapon, botulism remains a global public health concern. Vaccination against BoNT, although an effective strategy, remains undesirable due to the growing expectation around therapeutic use of BoNTs in various pathological conditions. This review focuses on the current approaches for botulism control by immunotherapy, highlighting the future challenges while the molecular underpinnings among subtypes variants and BoNT sequences found in non-clostridial species remain to be elucidated.
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Affiliation(s)
- Christine Rasetti-Escargueil
- Institut Pasteur, Département de Microbiologie, Unité des Toxines Bactériennes, 25 Rue du Docteur Roux, 75015 Paris, France.
| | - Michel R Popoff
- Institut Pasteur, Département de Microbiologie, Unité des Toxines Bactériennes, 25 Rue du Docteur Roux, 75015 Paris, France.
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9
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Davies JR, Liu SM, Acharya KR. Variations in the Botulinum Neurotoxin Binding Domain and the Potential for Novel Therapeutics. Toxins (Basel) 2018; 10:toxins10100421. [PMID: 30347838 PMCID: PMC6215321 DOI: 10.3390/toxins10100421] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/11/2018] [Accepted: 10/18/2018] [Indexed: 01/23/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are categorised into immunologically distinct serotypes BoNT/A to /G). Each serotype can also be further divided into subtypes based on differences in amino acid sequence. BoNTs are ~150 kDa proteins comprised of three major functional domains: an N-terminal zinc metalloprotease light chain (LC), a translocation domain (HN), and a binding domain (HC). The HC is responsible for targeting the BoNT to the neuronal cell membrane, and each serotype has evolved to bind via different mechanisms to different target receptors. Most structural characterisations to date have focussed on the first identified subtype within each serotype (e.g., BoNT/A1). Subtype differences within BoNT serotypes can affect intoxication, displaying different botulism symptoms in vivo, and less emphasis has been placed on investigating these variants. This review outlines the receptors for each BoNT serotype and describes the basis for the highly specific targeting of neuronal cell membranes. Understanding receptor binding is of vital importance, not only for the generation of novel therapeutics but also for understanding how best to protect from intoxication.
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Affiliation(s)
- Jonathan R Davies
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
| | - Sai Man Liu
- Ipsen Bioinnovation Limited, Abingdon OX14 4RY, UK.
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
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Sikorra S, Skiba M, Dorner MB, Weisemann J, Weil M, Valdezate S, Davletov B, Rummel A, Dorner BG, Binz T. Botulinum Neurotoxin F Subtypes Cleaving the VAMP-2 Q 58⁻K 59 Peptide Bond Exhibit Unique Catalytic Properties and Substrate Specificities. Toxins (Basel) 2018; 10:toxins10080311. [PMID: 30071628 PMCID: PMC6116196 DOI: 10.3390/toxins10080311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/23/2018] [Accepted: 07/30/2018] [Indexed: 11/16/2022] Open
Abstract
In the recent past, about 40 botulinum neurotoxin (BoNT) subtypes belonging to serotypes A, B, E, and F pathogenic to humans were identified among hundreds of independent isolates. BoNTs are the etiological factors of botulism and represent potential bioweapons; however, they are also recognized pharmaceuticals for the efficient counteraction of hyperactive nerve terminals in a variety of human diseases. The detailed biochemical characterization of subtypes as the basis for development of suitable countermeasures and possible novel therapeutic applications is lagging behind the increase in new subtypes. Here, we report the primary structure of a ninth subtype of BoNT/F. Its amino-acid sequence diverges by at least 8.4% at the holotoxin and 13.4% at the enzymatic domain level from all other known BoNT/F subtypes. We found that BoNT/F9 shares the scissile Q58/K59 bond in its substrate vesicle associated membrane protein 2 with the prototype BoNT/F1. Comparative biochemical analyses of four BoNT/F enzymatic domains showed that the catalytic efficiencies decrease in the order F1 > F7 > F9 > F6, and vary by up to a factor of eight. KM values increase in the order F1 > F9 > F6 ≈ F7, whereas kcat decreases in the order F7 > F1 > F9 > F6. Comparative substrate scanning mutagenesis studies revealed a unique pattern of crucial substrate residues for each subtype. Based upon structural coordinates of F1 bound to an inhibitor polypeptide, the mutational analyses suggest different substrate interactions in the substrate binding channel of each subtype.
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Affiliation(s)
- Stefan Sikorra
- Institute of Cell Biochemistry, OE 4310, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Martin Skiba
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Martin B Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Jasmin Weisemann
- Institute of Toxicology, OE 5340, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Mirjam Weil
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Sylvia Valdezate
- Reference and Research Laboratory for Taxonomy, Spanish National Centre of Microbiology, Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Bazbek Davletov
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| | - Andreas Rummel
- Institute of Toxicology, OE 5340, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Brigitte G Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Thomas Binz
- Institute of Cell Biochemistry, OE 4310, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
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11
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Feltrup TM, Patel K, Kumar R, Cai S, Singh BR. A novel role of C-terminus in introducing a functionally flexible structure critical for the biological activity of botulinum neurotoxin. Sci Rep 2018; 8:8884. [PMID: 29891845 PMCID: PMC5995822 DOI: 10.1038/s41598-018-26764-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
Botulinum neurotoxin (BoNT) is responsible for botulism, a clinical condition resulting in flaccid muscle paralysis and potentially death. The light chain is responsible for its intracellular toxicity through its endopeptidase activity. Available crystal structures of BoNT/A light chains (LCA) are based on various truncated versions (tLCA) of the full-length LCA (fLCA) and do not necessarily reflect the true structure of LCA in solution. The understanding of the mechanism of action, longevity of intoxication, and an improved development of endopeptidase inhibitors are dependent on first having a better insight into the structure of LCA in solution. Using an array of biophysical techniques, we report that the fLCA structure is significantly more flexible than tLCA in solution, which may be responsible for its dramatically higher enzymatic activity. This seems to be achieved by a much stronger, more rapid binding to substrate (SNAP-25) of the fLCA compared to tLCA. These results suggest that the C-terminus of LCA plays a critical role in introducing a flexible structure, which is essential for its biological function. This is the first report of such a massive structural role of the C-terminus of a protein being critical for maintaining a functional state.
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Affiliation(s)
- Thomas M Feltrup
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Kruti Patel
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, North Dartmouth, MA, 02747, USA
| | - Shuowei Cai
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Bal Ram Singh
- Botulinum Research Center, Institute of Advanced Sciences, North Dartmouth, MA, 02747, USA.
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12
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Hackett G, Moore K, Burgin D, Hornby F, Gray B, Elliott M, Mir I, Beard M. Purification and Characterization of Recombinant Botulinum Neurotoxin Serotype FA, Also Known as Serotype H. Toxins (Basel) 2018; 10:E195. [PMID: 29751611 PMCID: PMC5983251 DOI: 10.3390/toxins10050195] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 11/17/2022] Open
Abstract
We have purified and characterized recombinant botulinum neurotoxin serotype FA (BoNT/FA). This protein has also been named as a new serotype (serotype H), but the classification has been controversial. A lack of well-characterized, highly pure material has been a roadblock to study. Here we report purification and characterization of enzymatically active, and of inactive nontoxic, recombinant forms of BoNT/FA as tractable alternatives to purifying this neurotoxin from native Clostridium botulinum. BoNT/FA cleaves the same intracellular target proteins as BoNT/F1 and other F serotype BoNTs; the intracellular targets are vesicle associated membrane proteins (VAMP) 1, 2 and 3. BoNT/FA cleaves the same site in VAMP-2 as BoNT/F5, which is different from the cleavage site of other F serotype BoNTs. BoNT/FA has slower enzyme kinetics than BoNT/F1 in a cell-free protease assay and is less potent at inhibiting ex vivo nerve-stimulated skeletal muscle contraction. In contrast, BoNT/FA is more potent at inhibiting neurotransmitter release from cultured neurons.
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Affiliation(s)
- Gavin Hackett
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Kevin Moore
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - David Burgin
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Fraser Hornby
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Bryony Gray
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Mark Elliott
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Imran Mir
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Matthew Beard
- Ipsen Bioinnovation Ltd., 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
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Li M, Lee D, Obi CR, Freeberg JK, Farr-Jones S, Tomic MT. An ambient temperature-stable antitoxin of nine co-formulated antibodies for botulism caused by serotypes A, B and E. PLoS One 2018; 13:e0197011. [PMID: 29746518 PMCID: PMC5944936 DOI: 10.1371/journal.pone.0197011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/24/2018] [Indexed: 12/11/2022] Open
Abstract
Safe and effective antitoxins to treat and prevent botulism are needed for biodefense. We have developed recombinant antibody-based therapeutics for botulinum neurotoxin (BoNT) serotypes A, B, and E. The mechanism of action of this antitoxin requires that three mAbs bind one toxin molecule to achieve clearance. Here we present a co-formulation of an antitoxin to the three most important serotypes. Combining these antibodies obviates the need to identify the serotype causing intoxication prior to drug administration, which would facilitate administration. The lyophilized powder formulation contains nine mAbs, three mAbs for each of the three serotypes (A, B, E). The formulation was stored as a liquid and lyophilized powder for up to one year, and characterized by binding affinity and multiple physicochemical methods. No significant increase in soluble higher order aggregates, cleavage products, or change in charge isoforms was measured after storage as a lyophilized powder at 50°C for one year. Furthermore, toxin-domain binding ELISA data indicated that each of the individual antibodies in the lyophilized drug product showed essentially full binding capability to their respective toxin domains after being stored at 50°C for one year. Physicochemical characterization of the formulation demonstrated the nine individual mAbs were remarkably stable. This work demonstrates feasibility of lyophilized, oligoclonal antibody therapies for biodefense with ambient temperature stability, that would facilitate stockpiling, distribution, and administration.
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Affiliation(s)
- Mingxiang Li
- XOMA Corp., Berkeley, CA, United States of America
| | - Dennis Lee
- XOMA Corp., Berkeley, CA, United States of America
| | - Chidi R. Obi
- XOMA Corp., Berkeley, CA, United States of America
| | | | - Shauna Farr-Jones
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Milan T. Tomic
- XOMA Corp., Berkeley, CA, United States of America
- * E-mail:
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14
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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15
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Khounlo R, Kim J, Yin L, Shin YK. Botulinum Toxins A and E Inflict Dynamic Destabilization on t-SNARE to Impair SNARE Assembly and Membrane Fusion. Structure 2017; 25:1679-1686.e5. [PMID: 29033286 PMCID: PMC5685167 DOI: 10.1016/j.str.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/24/2017] [Accepted: 09/12/2017] [Indexed: 01/08/2023]
Abstract
Botulinum toxins (BoNTs) A and E block neurotransmitter release by specifically cleaving the C- terminal ends of SNAP-25, a plasma membrane SNARE protein. Here, we find that SNAP-25A and E, the cleavage products of BoNT A and E, respectively, terminate membrane fusion via completely different mechanisms. Combined studies of single-molecule FRET and single-vesicle fusion assays reveal that SNAP-25E is incapable of supporting SNARE pairing and thus, vesicle docking. In contrast, SNAP-25A facilitates robust SNARE pairing and vesicle docking with somewhat reduced SNARE zippering, which leads to severe impairment of fusion pore opening. The electron paramagnetic resonance results show that the discrepancy between SNAP-25A and E might stem from the extent of the dynamic destabilization of the t-SNARE core at the N-terminal half, which plays a pivotal role in nucleating SNARE complex formation. Thus, the results provide insights into the structure/dynamics-based mechanism by which BoNT A and E impair membrane fusion.
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Affiliation(s)
- Ryan Khounlo
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Jaewook Kim
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Linxiang Yin
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Yeon-Kyun Shin
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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16
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López de la Paz M, Scheps D, Jurk M, Hofmann F, Frevert J. Rational design of botulinum neurotoxin A1 mutants with improved oxidative stability. Toxicon 2017; 147:54-57. [PMID: 29042311 DOI: 10.1016/j.toxicon.2017.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 07/25/2017] [Accepted: 10/13/2017] [Indexed: 11/19/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most potent toxic proteins to mankind known but applied in low doses trigger a localized muscle paralysis that is beneficial for the therapy of several neurological disorders and aesthetic treatment. The paralytic effect is generated by the enzymatic activity of the light chain (LC) that cleaves specifically one of the SNARE proteins responsible for neurotransmitter exocytosis. The activity of the LC in a BoNT-containing therapeutic can be compromised by denaturing agents present during manufacturing and/or in the cell. Stabilization of the LC by reducing vulnerability towards denaturants would thus be advantageous for the development of BoNT-based therapeutics. In this work, we focused on increasing the stability of LC of BoNT/A1 (LC/A1) towards oxidative stress. We tackled this task by rational design of mutations at cysteine and methionine LC/A1 sites. Designed mutants showed improved oxidative stability in vitro and equipotency to wildtype toxin in vivo. Our results suggest that suitable modification of the catalytic domain can lead to more stable BoNTs without impairing their therapeutic efficacy.
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Affiliation(s)
| | - Daniel Scheps
- Merz Pharmaceuticals GmbH Potsdam, Hermannswerder Haus 15, 14473 Potsdam, Germany
| | - Marcel Jurk
- Merz Pharmaceuticals GmbH Potsdam, Hermannswerder Haus 15, 14473 Potsdam, Germany
| | - Fred Hofmann
- Merz Pharmaceuticals GmbH Potsdam, Hermannswerder Haus 15, 14473 Potsdam, Germany
| | - Jürgen Frevert
- Merz Pharmaceuticals GmbH Potsdam, Hermannswerder Haus 15, 14473 Potsdam, Germany.
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17
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Takehara M, Takagishi T, Seike S, Oda M, Sakaguchi Y, Hisatsune J, Ochi S, Kobayashi K, Nagahama M. Cellular Entry of Clostridium perfringens Iota-Toxin and Clostridium botulinum C2 Toxin. Toxins (Basel) 2017; 9:toxins9080247. [PMID: 28800062 PMCID: PMC5577581 DOI: 10.3390/toxins9080247] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 07/31/2017] [Accepted: 08/09/2017] [Indexed: 12/05/2022] Open
Abstract
Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin are composed of two non-linked proteins, one being the enzymatic component and the other being the binding/translocation component. These latter components recognize specific receptors and oligomerize in plasma membrane lipid-rafts, mediating the uptake of the enzymatic component into the cytosol. Enzymatic components induce actin cytoskeleton disorganization through the ADP-ribosylation of actin and are responsible for cell rounding and death. This review focuses upon the recent advances in cellular internalization of clostridial binary toxins.
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Affiliation(s)
- Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Soshi Seike
- Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima 737-0112, Japan.
| | - Masataka Oda
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Yamashina, Kyoto 607-8414, Japan.
| | - Yoshihiko Sakaguchi
- Department of Microbiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
| | - Junzo Hisatsune
- Department of Bacteriology, Graduate school of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Sadayuki Ochi
- Faculty of Pharmacy, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama-shi, Kanagawa 245-0066, Japan.
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
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18
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Sagane Y, Mutoh S, Koizumi R, Suzuki T, Miyashita SI, Miyata K, Ohyama T, Niwa K, Watanabe T. Reversible Association of the Hemagglutinin Subcomplex, HA-33/HA-17 Trimer, with the Botulinum Toxin Complex. Protein J 2017; 36:417-424. [PMID: 28707196 DOI: 10.1007/s10930-017-9733-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Botulinum neurotoxin (BoNT) associates with nontoxic proteins, either a nontoxic nonhemagglutinin (NTNHA) or the complex of NTNHA and hemagglutinin (HA), to form M- or L-toxin complexes (TCs). Single BoNT and NTNHA molecules are associated and form M-TC. A trimer of the 70-kDa HA protein (HA-70) attaches to the M-TC to form M-TC/HA-70. Further, 1-3 arm-like 33- and 17-kDa HA molecules (HA-33/HA-17 trimer), consisting of 1 HA-17 protein and 2 HA-33 proteins, can attach to the M-TC/HA-70 complex, yielding 1-, 2-, and 3-arm L-TC. In this study, the purified 1- and 2-arm L-TCs spontaneously converted into another L-TC species after acquiring the HA-33/HA-17 trimer from other TCs during long-term storage and freezing/thawing. Transmission electron microscopy analysis provided evidence of the formation of detached HA-33/HA-17 trimers in the purified TC preparation. These findings provide evidence of reversible association/dissociation of the M-TC/HA-70 complex with the HA-33/HA-17 trimers, as well as dynamic conversion of the quaternary structure of botulinum TC in culture.
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Affiliation(s)
- Yoshimasa Sagane
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan.
| | - Shingo Mutoh
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
- Department of Health and Nutrition, Faculty of Human Science, Hokkaido Bunkyo University, 5-196-1 Kogane-chuo, Eniwa, 061-1449, Japan
| | - Ryosuke Koizumi
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
| | - Tomonori Suzuki
- Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan
| | - Shin-Ichiro Miyashita
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
| | - Keita Miyata
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
- Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi, 487-8501, Japan
| | - Tohru Ohyama
- Department of Health and Nutrition, Faculty of Human Science, Hokkaido Bunkyo University, 5-196-1 Kogane-chuo, Eniwa, 061-1449, Japan
| | - Koichi Niwa
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
| | - Toshihiro Watanabe
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, 099-2493, Japan
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19
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Yao G, Lam KH, Perry K, Weisemann J, Rummel A, Jin R. Crystal Structure of the Receptor-Binding Domain of Botulinum Neurotoxin Type HA, Also Known as Type FA or H. Toxins (Basel) 2017; 9:toxins9030093. [PMID: 28282873 PMCID: PMC5371848 DOI: 10.3390/toxins9030093] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/03/2017] [Accepted: 03/04/2017] [Indexed: 01/02/2023] Open
Abstract
Botulinum neurotoxins (BoNTs), which have been exploited as cosmetics and muscle-disorder treatment medicines for decades, are well known for their extreme neurotoxicity to humans. They pose a potential bioterrorism threat because they cause botulism, a flaccid muscular paralysis-associated disease that requires immediate antitoxin treatment and intensive care over a long period of time. In addition to the existing seven established BoNT serotypes (BoNT/A–G), a new mosaic toxin type termed BoNT/HA (aka type FA or H) was reported recently. Sequence analyses indicate that the receptor-binding domain (HC) of BoNT/HA is ~84% identical to that of BoNT/A1. However, BoNT/HA responds differently to some potent BoNT/A-neutralizing antibodies (e.g., CR2) that target the HC. Therefore, it raises a serious concern as to whether BoNT/HA poses a new threat to our biosecurity. In this study, we report the first high-resolution crystal structure of BoNT/HA-HC at 1.8 Å. Sequence and structure analyses reveal that BoNT/HA and BoNT/A1 are different regarding their binding to cell-surface receptors including both polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Furthermore, the new structure also provides explanations for the ~540-fold decreased affinity of antibody CR2 towards BoNT/HA compared to BoNT/A1. Taken together, these new findings advance our understanding of the structure and function of this newly identified toxin at the molecular level, and pave the way for the future development of more effective countermeasures.
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Affiliation(s)
- Guorui Yao
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
| | - Kwok-Ho Lam
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA.
| | - Jasmin Weisemann
- Institut für Toxikologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Rongsheng Jin
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
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20
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Sagane Y, Hayashi S, Akiyama T, Matsumoto T, Hasegawa K, Yamano A, Suzuki T, Niwa K, Watanabe T, Yajima S. Conformational divergence in the HA-33/HA-17 trimer of serotype C and D botulinum toxin complex. Biochem Biophys Res Commun 2016; 476:280-285. [PMID: 27237978 DOI: 10.1016/j.bbrc.2016.05.113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 05/22/2016] [Indexed: 11/17/2022]
Abstract
Clostridium botulinum produces a large toxin complex (L-TC) comprising botulinum neurotoxin associated with auxiliary nontoxic proteins. A complex of 33- and 17-kDa hemagglutinins (an HA-33/HA-17 trimer) enhances L-TC transport across the intestinal epithelial cell layer via binding HA-33 to a sugar on the cell surface. At least two subtypes of serotype C/D HA-33 exhibit differing preferences for the sugars sialic acid and galactose. Here, we compared the three-dimensional structures of the galactose-binding HA-33 and HA-33/HA-17 trimers produced by the C-Yoichi strain. Comparisons of serotype C/D HA-33 sequences reveal a variable region with relatively low sequence similarity across the C. botulinum strains; the variability of this region may influence the manner of sugar-recognition by HA-33. Crystal structures of sialic acid- and galactose-binding HA-33 are broadly similar in appearance. However, small-angle X-ray scattering revealed distinct solution structures for HA-33/HA-17 trimers. A structural change in the C-terminal variable region of HA-33 might cause a dramatic shift in the conformation and sugar-recognition mode of HA-33/HA-17 trimer.
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Affiliation(s)
- Yoshimasa Sagane
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan.
| | - Shintaro Hayashi
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan
| | - Tomonori Akiyama
- Department of Bioscience, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | | | - Kimiko Hasegawa
- Rigaku Corporation, 3-9-12 Matsubara-Cho, Akishima 196-8666, Japan
| | - Akihito Yamano
- Rigaku Corporation, 3-9-12 Matsubara-Cho, Akishima 196-8666, Japan
| | - Tomonori Suzuki
- Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Koichi Niwa
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan
| | - Toshihiro Watanabe
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan
| | - Shunsuke Yajima
- Department of Bioscience, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
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21
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Guo J, Chan EWC, Chen S. Comparative characterization of botulinum neurotoxin subtypes F1 and F7 featuring differential substrate recognition and cleavage mechanisms. Toxicon 2016; 111:77-85. [PMID: 26748154 DOI: 10.1016/j.toxicon.2015.12.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/27/2015] [Accepted: 12/29/2015] [Indexed: 11/18/2022]
Abstract
BoNT/F7, one of the seven subtypes of botulinum neurotoxin type F (F1 to F7), is the second-most divergent subtype of this group. Despite sharing >60% identity with BoNT/F1 at both holotoxin and enzymatic domain levels, it requires an N-terminal extended peptide substrate for efficient substrate cleavage, suggesting its unique substrate recognition and specificity mechanism. Substrate mapping and saturation mutagenesis analysis revealed that VAMP2 (20-65) was likely a minimally effective substrate for LC/F7 (light chain of BoNT/F7), and in addition, LC/F7 recognized VAMP2 in a unique way, which differed significantly from that of LC/F1, although both of them share similar substrate binding and hydrolysis mode. LC/F7 utilizes distinct pockets for specific substrate binding and recognition in particular for the B1, B2 and S2 sites recognitions. Our findings provide insights into the distinct substrate recognition features of BoNT subtypes and useful information for therapy development for BoNT/F.
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Affiliation(s)
- Jiubiao Guo
- Shenzhen Key Lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen 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
| | - Edward Wai Chi Chan
- Shenzhen Key Lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen 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
| | - Sheng Chen
- Shenzhen Key Lab for Food Biological Safety Control, Food Safety and Technology Research Center, Hong Kong PolyU Shen Zhen 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.
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22
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Abstract
Clostridium botulinum is a Gram-positive, spore-forming, anaerobic bacillus that produces a potent neurotoxin. Botulinum neurotoxins (BoNTs) are classified from serotypes A to H, and even though they have similar mechanisms of action, they show preferential hosts. In veterinary medicine, BoNT serotypes C and D are the most important, once several animal species are susceptible to them. Since BoNTs are the most potent toxins known in nature, the best way to control botulism in animals is through vaccination. However, current commercial vaccines are based on inactivated toxins (toxoids) and cells (bacterins) and present many drawbacks, such as a time-consuming production with variable antigen yield and biosafety risks. Recombinant vaccines, especially those produced by Escherichia coli expression system, have proved to be an interesting alternative to overcome these problems. E. coli is a very well-known microorganism that allows the production of large amounts of nontoxic recombinant antigens in a short period using simple culture medium reducing the production complexity and decreasing most of the biosafety risks involved in the process. We describe herein a method for the production of recombinant vaccines for veterinary medicine application, involving initial steps of gene design up to vaccine formulation and evaluation itself.
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Affiliation(s)
- Gustavo Marçal S G Moreira
- Laboratório de Imunologia Aplicada, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, CEP 96160-000, Brazil
| | - Clóvis Moreira
- Laboratório de Imunologia Aplicada, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, CEP 96160-000, Brazil
| | - Carlos Eduardo P da Cunha
- Laboratório de Imunologia Aplicada, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, CEP 96160-000, Brazil
| | - Marcelo Mendonça
- Laboratório de Imunologia Aplicada, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, CEP 96160-000, Brazil
| | - Fabricio R Conceição
- Laboratório de Imunologia Aplicada, Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, CEP 96160-000, Brazil.
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23
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Weisemann J, Krez N, Fiebig U, Worbs S, Skiba M, Endermann T, Dorner MB, Bergström T, Muñoz A, Zegers I, Müller C, Jenkinson SP, Avondet MA, Delbrassinne L, Denayer S, Zeleny R, Schimmel H, Åstot C, Dorner BG, Rummel A. Generation and Characterization of Six Recombinant Botulinum Neurotoxins as Reference Material to Serve in an International Proficiency Test. Toxins (Basel) 2015; 7:5035-54. [PMID: 26703728 PMCID: PMC4690111 DOI: 10.3390/toxins7124861] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 12/22/2022] Open
Abstract
The detection and identification of botulinum neurotoxins (BoNT) is complex due to the existence of seven serotypes, derived mosaic toxins and more than 40 subtypes. Expert laboratories currently use different technical approaches to detect, identify and quantify BoNT, but due to the lack of (certified) reference materials, analytical results can hardly be compared. In this study, the six BoNT/A1–F1 prototypes were successfully produced by recombinant techniques, facilitating handling, as well as improving purity, yield, reproducibility and biosafety. All six BoNTs were quantitatively nicked into active di-chain toxins linked by a disulfide bridge. The materials were thoroughly characterized with respect to purity, identity, protein concentration, catalytic and biological activities. For BoNT/A1, B1 and E1, serotypes pathogenic to humans, the catalytic activity and the precise protein concentration were determined by Endopep-mass spectrometry and validated amino acid analysis, respectively. In addition, BoNT/A1, B1, E1 and F1 were successfully detected by immunological assays, unambiguously identified by mass spectrometric-based methods, and their specific activities were assigned by the mouse LD50 bioassay. The potencies of all six BoNT/A1–F1 were quantified by the ex vivo mouse phrenic nerve hemidiaphragm assay, allowing a direct comparison. In conclusion, highly pure recombinant BoNT reference materials were produced, thoroughly characterized and employed as spiking material in a worldwide BoNT proficiency test organized by the EQuATox consortium.
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Affiliation(s)
| | - Nadja Krez
- Toxogen GmbH, Feodor-Lynen-Str. 35, 30625 Hannover, Germany.
| | - Uwe Fiebig
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin Skiba
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Tanja Endermann
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin B Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Tomas Bergström
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Cementvägen 20, 90182 Umeå, Sweden.
| | - Amalia Muñoz
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Ingrid Zegers
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Christian Müller
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Stephen P Jenkinson
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Marc-Andre Avondet
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Laurence Delbrassinne
- Scientific Service of Food-Borne Pathogens, Operational Directorate of Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Sarah Denayer
- Scientific Service of Food-Borne Pathogens, Operational Directorate of Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Reinhard Zeleny
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Heinz Schimmel
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Crister Åstot
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Cementvägen 20, 90182 Umeå, Sweden.
| | - Brigitte G Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Andreas Rummel
- Toxogen GmbH, Feodor-Lynen-Str. 35, 30625 Hannover, Germany.
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24
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Abstract
Botulinum neurotoxins (BoNT) cause the disease botulism, a flaccid paralysis of the muscle. They are also very effective, widely used medicines applied locally in sub-nanogram quantities. BoNTs are released together with several non-toxic, associated proteins as progenitor toxin complexes (PCT) by Clostridium botulinum to become highly potent oral poisons ingested via contaminated food. They block the neurotransmission in susceptible animals and humans already in nanogram quantities due to their specific ability to enter motoneurons and to cleave only selected neuronal proteins involved in neuroexocytosis. BoNTs have developed a sophisticated strategy to passage the gastrointestinal tract and to be absorbed in the intestine of the host to finally attack neurons. A non-toxic non-hemagglutinin (NTNHA) forms a binary complex with BoNT to protect it from gastrointestinal degradation. This binary M-PTC is one component of the bi-modular 14-subunit ∼760 kDa large progenitor toxin complex. The other component is the structurally and functionally independent dodecameric hemagglutinin (HA) complex which facilitates the absorption on the intestinal epithelium by glycan binding. Subsequent to its transcytosis the HA complex disrupts the tight junction of the intestinal barrier from the basolateral side by binding to E-cadherin. Now, the L-PTC can also enter the circulation by paracellular routes in much larger quantities. From here, the dissociated BoNTs reach the neuromuscular junction and accumulate via interaction with polysialo gangliosides, complex glycolipids, on motoneurons at the neuromuscular junction. Subsequently, additional specific binding to luminal segments of synaptic vesicles proteins like SV2 and synaptotagmin leads to their uptake. Finally, the neurotoxins shut down the synaptic vesicle cycle, which they had exploited before to enter their target cells, via specific cleavage of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, which constitute the core components of the cellular membrane fusion machinery.
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Affiliation(s)
- Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30623 Hannover, Germany.
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25
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Kim DW, Lee SK, Ahnn J. Botulinum Toxin as a Pain Killer: Players and Actions in Antinociception. Toxins (Basel) 2015; 7:2435-53. [PMID: 26134255 PMCID: PMC4516922 DOI: 10.3390/toxins7072435] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 06/19/2015] [Accepted: 06/23/2015] [Indexed: 11/17/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) have been widely used to treat a variety of clinical ailments associated with pain. The inhibitory action of BoNTs on synaptic vesicle fusion blocks the releases of various pain-modulating neurotransmitters, including glutamate, substance P (SP), and calcitonin gene-related peptide (CGRP), as well as the addition of pain-sensing transmembrane receptors such as transient receptor potential (TRP) to neuronal plasma membrane. In addition, growing evidence suggests that the analgesic and anti-inflammatory effects of BoNTs are mediated through various molecular pathways. Recent studies have revealed that the detailed structural bases of BoNTs interact with their cellular receptors and SNAREs. In this review, we discuss the molecular and cellular mechanisms related to the efficacy of BoNTs in alleviating human pain and insights on engineering the toxins to extend therapeutic interventions related to nociception.
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Affiliation(s)
- Dong-Wan Kim
- Department of Life Science, School of Natural Science, Hanyang University, Seoul 133-791, Korea.
- BK21 PLUS Life Science for BioDefense Research (BDR) Team, Hanyang University, Seoul 133-791, Korea.
| | - Sun-Kyung Lee
- Department of Life Science, School of Natural Science, Hanyang University, Seoul 133-791, Korea.
- BK21 PLUS Life Science for BioDefense Research (BDR) Team, Hanyang University, Seoul 133-791, Korea.
- The Research Institute for Natural Science, Hanyang University, Seoul 133-791, Korea.
| | - Joohong Ahnn
- Department of Life Science, School of Natural Science, Hanyang University, Seoul 133-791, Korea.
- BK21 PLUS Life Science for BioDefense Research (BDR) Team, Hanyang University, Seoul 133-791, Korea.
- The Research Institute for Natural Science, Hanyang University, Seoul 133-791, Korea.
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26
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Kalb SR, Baudys J, Wang D, Barr JR. Recommended mass spectrometry-based strategies to identify botulinum neurotoxin-containing samples. Toxins (Basel) 2015; 7:1765-78. [PMID: 25996606 PMCID: PMC4448173 DOI: 10.3390/toxins7051765] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 01/01/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) cause the disease called botulism, which can be lethal. BoNTs are proteins secreted by some species of clostridia and are known to cause paralysis by interfering with nerve impulse transmission. Although the human lethal dose of BoNT is not accurately known, it is estimated to be between 0.1 μg to 70 μg, so it is important to enable detection of small amounts of these toxins. Our laboratory previously reported on the development of Endopep-MS, a mass-spectrometric‑based endopeptidase method to detect, differentiate, and quantify BoNT immunoaffinity purified from complex matrices. In this work, we describe the application of Endopep-MS for the analysis of thirteen blinded samples supplied as part of the EQuATox proficiency test. This method successfully identified the presence or absence of BoNT in all thirteen samples and was able to successfully differentiate the serotype of BoNT present in the samples, which included matrices such as buffer, milk, meat extract, and serum. Furthermore, the method yielded quantitative results which had z-scores in the range of -3 to +3 for quantification of BoNT/A containing samples. These results indicate that Endopep-MS is an excellent technique for detection, differentiation, and quantification of BoNT in complex matrices.
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Affiliation(s)
- Suzanne R Kalb
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
| | - Jakub Baudys
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
| | - Dongxia Wang
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
| | - John R Barr
- Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA.
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27
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Savage AC, Buckley N, Halliwell J, Gwenin C. Botulinum neurotoxin serotypes detected by electrochemical impedance spectroscopy. Toxins (Basel) 2015; 7:1544-55. [PMID: 25954998 PMCID: PMC4448162 DOI: 10.3390/toxins7051544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 04/26/2015] [Accepted: 04/30/2015] [Indexed: 12/29/2022] Open
Abstract
Botulinum neurotoxin is one of the deadliest biological toxins known to mankind and is able to cause the debilitating disease botulism. The rapid detection of the different serotypes of botulinum neurotoxin is essential for both diagnosis of botulism and identifying the presence of toxin in potential cases of terrorism and food contamination. The modes of action of botulinum neurotoxins are well-established in literature and differ for each serotype. The toxins are known to specifically cleave portions of the SNARE proteins SNAP-25 or VAMP; an interaction that can be monitored by electrochemical impedance spectroscopy. This study presents a SNAP-25 and a VAMP biosensors for detecting the activity of five botulinum neurotoxin serotypes (A-E) using electrochemical impedance spectroscopy. The biosensors are able to detect concentrations of toxins as low as 25 fg/mL, in a short time-frame compared with the current standard methods of detection. Both biosensors show greater specificity for their compatible serotypes compared with incompatible serotypes and denatured toxins.
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Affiliation(s)
- Alison C Savage
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales LL57 2DG, UK.
| | - Nicholas Buckley
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales LL57 2DG, UK.
| | - Jennifer Halliwell
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales LL57 2DG, UK.
| | - Christopher Gwenin
- School of Chemistry, Bangor University, Bangor, Gwynedd, Wales LL57 2DG, UK.
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28
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Lam KH, Yao G, Jin R. Diverse binding modes, same goal: The receptor recognition mechanism of botulinum neurotoxin. Prog Biophys Mol Biol 2015; 117:225-231. [PMID: 25701633 DOI: 10.1016/j.pbiomolbio.2015.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/29/2015] [Accepted: 02/10/2015] [Indexed: 12/30/2022]
Abstract
Botulinum neurotoxins (BoNTs) are among the most deadly toxins known. They act rapidly in a highly specific manner to block neurotransmitter release by cleaving the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) complex at neuromuscular junctions. The extreme toxicity of BoNTs relies predominantly on their neurotropism that is accomplished by recognition of two host receptors, a polysialo-ganglioside and in the majority of cases a synaptic vesicle protein, through their receptor-binding domains. Two proteins, synaptotagmin and synaptic vesicle glycoprotein 2, have been identified as the receptors for various serotypes of BoNTs. Here, we review recent breakthroughs in the structural studies of BoNT-protein receptor recognitions that highlight a range of diverse mechanisms by which BoNTs manipulate host neuronal proteins for highly specific uptake at neuromuscular junctions.
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Affiliation(s)
- Kwok-Ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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29
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Matsui T, Gu S, Lam KH, Carter LG, Rummel A, Mathews II, Jin R. Structural basis of the pH-dependent assembly of a botulinum neurotoxin complex. J Mol Biol 2014; 426:3773-3782. [PMID: 25240768 PMCID: PMC4252799 DOI: 10.1016/j.jmb.2014.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/21/2014] [Accepted: 09/10/2014] [Indexed: 01/01/2023]
Abstract
Botulinum neurotoxins (BoNTs) are among the most poisonous biological substances known. They assemble with non-toxic non-hemagglutinin (NTNHA) protein to form the minimally functional progenitor toxin complexes (M-PTC), which protects BoNT in the gastrointestinal tract and releases it upon entry into the circulation. Here we provide molecular insight into the assembly between BoNT/A and NTNHA-A using small-angle X-ray scattering. We found that the free form BoNT/A maintains a pH-independent conformation with limited domain flexibility. Intriguingly, the free form NTNHA-A adopts pH-dependent conformational changes due to a torsional motion of its C-terminal domain. Once forming a complex at acidic pH, they each adopt a stable conformation that is similar to that observed in the crystal structure of the M-PTC. Our results suggest that assembly of the M-PTC depends on the environmental pH and that the complex form of BoNT/A is induced by interacting with NTNHA-A at acidic pH.
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Affiliation(s)
- Tsutomu Matsui
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA.
| | - Shenyan Gu
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Kwok-Ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Lester G Carter
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Irimpan I Mathews
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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30
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Sugawara Y, Yutani M, Amatsu S, Matsumura T, Fujinaga Y. Functional dissection of the Clostridium botulinum type B hemagglutinin complex: identification of the carbohydrate and E-cadherin binding sites. PLoS One 2014; 9:e111170. [PMID: 25340348 PMCID: PMC4207779 DOI: 10.1371/journal.pone.0111170] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/22/2014] [Indexed: 11/28/2022] Open
Abstract
Botulinum neurotoxin (BoNT) inhibits neurotransmitter release in motor nerve endings, causing botulism, a condition often resulting from ingestion of the toxin or toxin-producing bacteria. BoNTs are always produced as large protein complexes by associating with a non-toxic protein, non-toxic non-hemagglutinin (NTNH), and some toxin complexes contain another non-toxic protein, hemagglutinin (HA), in addition to NTNH. These accessory proteins are known to increase the oral toxicity of the toxin dramatically. NTNH has a protective role against the harsh conditions in the digestive tract, while HA is considered to facilitate intestinal absorption of the toxin by intestinal binding and disruption of the epithelial barrier. Two specific activities of HA, carbohydrate and E-cadherin binding, appear to be involved in these processes; however, the exact roles of these activities in the pathogenesis of botulism remain unclear. The toxin is conventionally divided into seven serotypes, designated A through G. In this study, we identified the amino acid residues critical for carbohydrate and E-cadherin binding in serotype B HA. We constructed mutants defective in each of these two activities and examined the relationship of these activities using an in vitro intestinal cell culture model. Our results show that the carbohydrate and E-cadherin binding activities are functionally and structurally independent. Carbohydrate binding potentiates the epithelial barrier-disrupting activity by enhancing cell surface binding, while E-cadherin binding is essential for the barrier disruption.
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Affiliation(s)
- Yo Sugawara
- Laboratory of Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Yamada-oka, Suita, Osaka, Japan
| | - Masahiro Yutani
- Laboratory of Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Yamada-oka, Suita, Osaka, Japan
| | - Sho Amatsu
- Laboratory of Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Yamada-oka, Suita, Osaka, Japan
| | - Takuhiro Matsumura
- Laboratory of Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Yamada-oka, Suita, Osaka, Japan
| | - Yukako Fujinaga
- Laboratory of Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Yamada-oka, Suita, Osaka, Japan
- * E-mail:
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31
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Lee K, Lam KH, Kruel AM, Perry K, Rummel A, Jin R. High-resolution crystal structure of HA33 of botulinum neurotoxin type B progenitor toxin complex. Biochem Biophys Res Commun 2014; 446:568-73. [PMID: 24631690 DOI: 10.1016/j.bbrc.2014.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
Abstract
Botulinum neurotoxins (BoNTs) are produced as progenitor toxin complexes (PTCs) by Clostridium botulinum. The PTCs are composed of BoNT and non-toxic neurotoxin-associated proteins (NAPs), which serve to protect and deliver BoNT through the gastrointestinal tract in food borne botulism. HA33 is a key NAP component that specifically recognizes host carbohydrates and helps enrich PTC on the intestinal lumen preceding its transport across the epithelial barriers. Here, we report the crystal structure of HA33 of type B PTC (HA33/B) in complex with lactose at 1.46Å resolution. The structural comparisons among HA33 of serotypes A-D reveal two different HA33-glycan interaction modes. The glycan-binding pockets on HA33/A and B are more suitable to recognize galactose-containing glycans in comparison to the equivalent sites on HA33/C and D. On the contrary, HA33/C and D could potentially recognize Neu5Ac as an independent receptor, whereas HA33/A and B do not. These findings indicate that the different oral toxicity and host susceptibility observed among different BoNT serotypes could be partly determined by the serotype-specific interaction between HA33 and host carbohydrate receptors. Furthermore, we have identified a key structural water molecule that mediates the HA33/B-lactose interactions. It provides the structural basis for development of new receptor-mimicking compounds, which have enhanced binding affinity with HA33 through their water-displacing moiety.
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Affiliation(s)
- Kwangkook Lee
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Kwok-Ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | | | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL, USA
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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Tautzenberger A, Förtsch C, Zwerger C, Dmochewitz L, Kreja L, Ignatius A, Barth H. C3 rho-inhibitor for targeted pharmacological manipulation of osteoclast-like cells. PLoS One 2013; 8:e85695. [PMID: 24386487 PMCID: PMC3874027 DOI: 10.1371/journal.pone.0085695] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/05/2013] [Indexed: 11/18/2022] Open
Abstract
The C3 toxins from Clostridium botulinum (C3bot) and Clostridium limosum (C3lim) as well as C3-derived fusion proteins are selectively taken up into the cytosol of monocytes/macrophages where the C3-catalyzed ADP-ribosylation of Rho results in inhibition of Rho-signalling and characteristic morphological changes. Since the fusion toxin C2IN-C3lim was efficiently taken up into and inhibited proliferation of murine macrophage-like RAW 264.7 cells, its effects on RAW 264.7-derived osteoclasts were investigated. C2IN-C3lim was taken up into differentiated osteoclasts and decreased their resorption activity. In undifferentiated RAW 264.7 cells, C2IN-C3lim-treatment significantly decreased their differentiation into osteoclasts as determined by counting the multi-nucleated, TRAP-positive cells. This inhibitory effect was concentration- and time-dependent and most efficient when C2IN-C3lim was applied in the early stage of osteoclast-formation. A single-dose application of C2IN-C3lim at day 0 and its subsequent removal at day 1 reduced the number of osteoclasts in a comparable manner while C2IN-C3lim-application at later time points did not reduce the number of osteoclasts to a comparable degree. Control experiments with an enzymatically inactive C3 protein revealed that the ADP-ribosylation of Rho was essential for the observed effects. In conclusion, the results indicate that Rho-activity is crucial during the early phase of osteoclast-differentiation. Other bone cell types such as pre-osteoblastic cells were not affected by C2IN-C3lim. Due to their cell-type selective and specific mode of action, C3 proteins and C3-fusions might be valuable tools for targeted pharmacological manipulation of osteoclast formation and activity, which could lead to development of novel therapeutic strategies against osteoclast-associated diseases.
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Affiliation(s)
- Andrea Tautzenberger
- Institute of Orthopaedic Research and Biomechanics, Centre of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Christina Förtsch
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Christian Zwerger
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Lydia Dmochewitz
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Ludwika Kreja
- Institute of Orthopaedic Research and Biomechanics, Centre of Musculoskeletal Research, University of Ulm, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopaedic Research and Biomechanics, Centre of Musculoskeletal Research, University of Ulm, Ulm, Germany
- * E-mail: (AI); (HB)
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
- * E-mail: (AI); (HB)
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33
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Garcia EA, Trivellin G, Aflorei ED, Powell M, Grieve J, Alusi G, Pobereskin L, Shariati B, Cudlip S, Roncaroli F, Mendoza N, Grossman AB, Harper EA, Korbonits M. Characterization of SNARE proteins in human pituitary adenomas: targeted secretion inhibitors as a new strategy for the treatment of acromegaly? J Clin Endocrinol Metab 2013; 98:E1918-26. [PMID: 24152687 DOI: 10.1210/jc.2013-2602] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT Targeted secretion inhibitors (TSIs), a new class of recombinant biotherapeutic proteins engineered from botulinum toxin, represent a novel approach for treating diseases with excess secretion. They inhibit hormone secretion from targeted cell types through cleavage of SNARE (soluble N-ethylmaleimide-sensitive factor-activating protein receptor) proteins. qGHRH-LH(N)/D is a TSI targeting pituitary somatotroph through binding to the GHRH-receptor and cleavage of the vesicle-associated membrane protein (VAMP) family of SNARE proteins. OBJECTIVE Our objective was to study SNARE protein expression in pituitary adenomas and to inhibit GH secretion from somatotropinomas using qGHRH-LH(N)/D. DESIGN We analyzed human pituitary adenoma analysis for SNARE expression and response to qGHRH-LH(N)/D treatment. SETTING The study was conducted in University Hospitals. PATIENTS We used pituitary adenoma samples from 25 acromegaly and 47 nonfunctioning pituitary adenoma patients. OUTCOME Vesicle-SNARE (VAMP1-3), target-SNARE (syntaxin1, SNAP-23, and SNAP-25), and GHRH-receptor detection with RT-qPCR, immunocytochemistry, and immunoblotting. Assessment of TSI catalytic activity on VAMPs and release of GH from adenoma cells. RESULTS SNARE proteins were variably expressed in pituitary samples. In vitro evidence using recombinant GFP-VAMP2&3 or pituitary adenoma lysates suggested sufficient catalytic activity of qGHRH-LH(N)/D to degrade VAMPs, but was unable to inhibit GH secretion in somatotropinoma cell cultures. CONCLUSIONS SNARE proteins are present in human pituitary somatotroph adenomas that can be targeted by TSIs to inhibit GH secretion. qGHRH-LH(N)/D was unable to inhibit GH secretion from human somatotroph adenoma cells. Further studies are required to understand how the SNARE proteins drive GH secretion in human somatotrophs to allow the development of novel TSIs with a potential therapeutic benefit.
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Affiliation(s)
- Edwin A Garcia
- Cancer Research UK Centre, Somers Building, Tremona Road, Southampton, SO16 6YD, UK.
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34
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Lee K, Gu S, Jin L, Le TTN, Cheng LW, Strotmeier J, Kruel AM, Yao G, Perry K, Rummel A, Jin R. Structure of a bimodular botulinum neurotoxin complex provides insights into its oral toxicity. PLoS Pathog 2013; 9:e1003690. [PMID: 24130488 PMCID: PMC3795040 DOI: 10.1371/journal.ppat.1003690] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 07/11/2013] [Indexed: 11/24/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and cause the fatal disease botulism, a flaccid paralysis of the muscle. BoNTs are released together with several auxiliary proteins as progenitor toxin complexes (PTCs) to become highly potent oral poisons. Here, we report the structure of a ∼760 kDa 14-subunit large PTC of serotype A (L-PTC/A) and reveal insight into its absorption mechanism. Using a combination of X-ray crystallography, electron microscopy, and functional studies, we found that L-PTC/A consists of two structurally and functionally independent sub-complexes. A hetero-dimeric 290 kDa complex protects BoNT, while a hetero-dodecameric 470 kDa complex facilitates its absorption in the harsh environment of the gastrointestinal tract. BoNT absorption is mediated by nine glycan-binding sites on the dodecameric sub-complex that forms multivalent interactions with carbohydrate receptors on intestinal epithelial cells. We identified monosaccharides that blocked oral BoNT intoxication in mice, which suggests a new strategy for the development of preventive countermeasures for BoNTs based on carbohydrate receptor mimicry. Food-borne botulinum neurotoxin (BoNT) poisoning results in fatal muscle paralysis. But how can BoNT–a large protein released by the bacteria clostridia–survive the hostile gastrointestinal (GI) tract to gain access to neurons that control muscle contraction? Here, we report the complete structure of a bimodular ∼760 kDa BoNT/A large progenitor toxin complex (L-PTC), which is composed of BoNT and four non-toxic bacterial proteins. The architecture of this bacterial machinery mimics an Apollo lunar module, whereby the “ascent stage” (a ∼290 kDa module) protects BoNT from destruction in the GI tract and the 3-arm “descent stage” (a ∼470 kDa module) mediates absorption of BoNT by binding to host carbohydrate receptors in the small intestine. This new finding has helped us identify the carbohydrate-binding sites and the monosaccharide IPTG as a prototypical oral inhibitor, which extends survival following lethal BoNT/A intoxication of mice. Hence, pre-treatment with small molecule inhibitors based on carbohydrate receptor mimicry can provide temporary protection against BoNT entry into the circulation.
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Affiliation(s)
- Kwangkook Lee
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Shenyan Gu
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Lei Jin
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
| | - Thi Tuc Nghi Le
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Luisa W. Cheng
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| | - Jasmin Strotmeier
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | | | - Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
- * E-mail: (AR); (RJ)
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
- Neuroscience, Aging and Stem Cell Center, Sanford-Burnham Medical Research Institute, La Jolla, California, United States of America
- * E-mail: (AR); (RJ)
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Leggett J, Harper E, Waite E, Marks P, Martinez A, Lightman S. GHRH receptor-targeted botulinum neurotoxin selectively inhibits pulsatile GH secretion in male rats. Endocrinology 2013; 154:3305-18. [PMID: 23825127 DOI: 10.1210/en.2012-2175] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Botulinum neurotoxin is a potent inhibitor of acetylcholine secretion and acts by cleaving members of the soluble N-ethylmaleimide-sensitive factor-attachment protein receptor family, which are critical to exocytotic vesicular secretion. However, the potential of botulinum neurotoxin for treating secretory disease is limited both by its neural selectivity and the necessity for direct injection into the relevant target tissue. To circumvent these limitations, a technology platform called targeted secretion inhibitors (TSIs) is being developed. TSIs are derived from botulinum neurotoxin but are retargeted to specific cell types to inhibit aberrant secretion. A TSI called qGHRH-LHN/D, with a GHRH receptor targeting domain and designed to specifically inhibit pituitary somatotroph GH release through cleavage of the N-ethylmaleimide-sensitive factor-attachment protein receptor protein, vesicle-associated membrane protein (VAMP), has recently been described. Here we show this TSI activates GHRH receptors in primary cultured rat pituicytes is internalized into these cells, depletes VAMP-3, and inhibits phorbol-12-myristate-13-acetate-induced GH secretion. In vivo studies show that this TSI, but not one with an inactive catalytic unit, produces a dose-dependent inhibition of pulsatile GH secretion, thus confirming its mechanism of action through VAMP cleavage. Selectivity of action has been shown by the lack of effect of this TSI in vivo on secretion from thyrotrophs, corticotrophs, and gonadotrophs. In the absence of suitable in vivo models, these data provide proof of concept for the use of somatotroph-targeted TSIs in the treatment of acromegaly and moreover raise the potential that TSIs could be used to target other diseases characterized by hypersecretion.
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MESH Headings
- Animals
- Biological Transport/drug effects
- Botulinum Toxins/chemistry
- Botulinum Toxins/genetics
- Botulinum Toxins/metabolism
- Botulinum Toxins/pharmacology
- Cells, Cultured
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Growth Hormone/blood
- Growth Hormone/metabolism
- Growth Hormone-Releasing Hormone/chemistry
- Growth Hormone-Releasing Hormone/genetics
- Growth Hormone-Releasing Hormone/metabolism
- Growth Hormone-Releasing Hormone/pharmacology
- Male
- Organ Specificity
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Peptide Fragments/pharmacology
- Periodicity
- Pituitary Gland, Anterior/cytology
- Pituitary Gland, Anterior/drug effects
- Pituitary Gland, Anterior/metabolism
- Protein Interaction Domains and Motifs
- Proteolysis/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptors, Neuropeptide/agonists
- Receptors, Neuropeptide/chemistry
- Receptors, Neuropeptide/metabolism
- Receptors, Pituitary Hormone-Regulating Hormone/agonists
- Receptors, Pituitary Hormone-Regulating Hormone/chemistry
- Receptors, Pituitary Hormone-Regulating Hormone/metabolism
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/metabolism
- Recombinant Fusion Proteins/pharmacology
- Somatotrophs/cytology
- Somatotrophs/drug effects
- Somatotrophs/metabolism
- Vesicle-Associated Membrane Protein 3/antagonists & inhibitors
- Vesicle-Associated Membrane Protein 3/metabolism
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Affiliation(s)
- James Leggett
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, University of Bristol, Whitson Street, Bristol BS1 3NY, United Kingdom
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Sagane Y, Hayashi S, Matsumoto T, Miyashita SI, Inui K, Miyata K, Yajima S, Suzuki T, Hasegawa K, Yamano A, Nishikawa A, Ohyama T, Watanabe T, Niwa K. Sugar-induced conformational change found in the HA-33/HA-17 trimer of the botulinum toxin complex. Biochem Biophys Res Commun 2013; 438:483-7. [PMID: 23916708 DOI: 10.1016/j.bbrc.2013.07.112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 07/28/2013] [Indexed: 11/18/2022]
Abstract
Large-sized botulinum toxin complex (L-TC) is formed by conjugation of neurotoxin, nontoxic nonhemagglutinin and hemagglutinin (HA) complex. The HA complex is formed by association of three HA-70 molecules and three HA-33/HA-17 trimers, comprised of a single HA-17 and two HA-33 proteins. The HA-33/HA-17 trimer isolated from serotype D L-TC has the ability to bind to and penetrate through the intestinal epithelial cell monolayer in a sialic acid-dependent manner, and thus it plays an important role in toxin delivery through the intestinal cell wall. In this study, we determined the solution structure of the HA-33/HA-17 trimer by using small-angle X-ray scattering (SAXS). The SAXS image of HA-33/HA-17 exhibited broadly similar appearance to the crystal image of the complex. On the other hand, in the presence of N-acetylneuraminic acid, glucose and galactose, the solution structure of the HA-33/HA-17 trimer was drastically altered compared to the structure in the absence of the sugars. Sugar-induced structural change of the HA-33/HA-17 trimer may contribute to cell binding and subsequent transport across the intestinal cell layer.
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Affiliation(s)
- Yoshimasa Sagane
- Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
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Dreon MS, Frassa MV, Ceolín M, Ituarte S, Qiu JW, Sun J, Fernández PE, Heras H. Novel animal defenses against predation: a snail egg neurotoxin combining lectin and pore-forming chains that resembles plant defense and bacteria attack toxins. PLoS One 2013; 8:e63782. [PMID: 23737950 PMCID: PMC3667788 DOI: 10.1371/journal.pone.0063782] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 04/07/2013] [Indexed: 11/19/2022] Open
Abstract
Although most eggs are intensely predated, the aerial egg clutches from the aquatic snail Pomacea canaliculata have only one reported predator due to unparalleled biochemical defenses. These include two storage-proteins: ovorubin that provides a conspicuous (presumably warning) coloration and has antinutritive and antidigestive properties, and PcPV2 a neurotoxin with lethal effect on rodents. We sequenced PcPV2 and studied whether it was able to withstand the gastrointestinal environment and reach circulation of a potential predator. Capacity to resist digestion was assayed using small-angle X-ray scattering (SAXS), fluorescence spectroscopy and simulated gastrointestinal proteolysis. PcPV2 oligomer is antinutritive, withstanding proteinase digestion and displaying structural stability between pH 4.0-10.0. cDNA sequencing and protein domain search showed that its two subunits share homology with membrane attack complex/perforin (MACPF)-like toxins and tachylectin-like lectins, a previously unknown structure that resembles plant Type-2 ribosome-inactivating proteins and bacterial botulinum toxins. The protomer has therefore a novel AB toxin combination of a MACPF-like chain linked by disulfide bonds to a lectin-like chain, indicating a delivery system for the former. This was further supported by observing PcPV2 binding to glycocalix of enterocytes in vivo and in culture, and by its hemaggutinating, but not hemolytic activity, which suggested an interaction with surface oligosaccharides. PcPV2 is able to get into predator's body as evidenced in rats and mice by the presence of circulating antibodies in response to sublethal oral doses. To our knowledge, a lectin-pore-forming toxin has not been reported before, providing the first evidence of a neurotoxic lectin in animals, and a novel function for ancient and widely distributed proteins. The acquisition of this unique neurotoxic/antinutritive/storage protein may confer the eggs a survival advantage, opening new perspectives in the study of the evolution of animal defensive strategies.
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Affiliation(s)
- Marcos Sebastián Dreon
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata (UNLP) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET CCT-La Plata), La Plata, Argentina
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Abstract
Botulinum neurotoxins are comprised of multiple identifiable protein domains. Recent advances in understanding the relationships between domain structure and neurotoxin function have provided a number of opportunities to engineer innovative therapeutic proteins that utilise the neurotoxins and neurotoxin domains. For example, recent insights into the properties of the catalytic, translocation and binding domains open up opportunities to develop botulinum neurotoxins with enhanced properties of selectivity, potency and duration of action. In parallel, the broad scope for utilisation of the individual domains is becoming clearer as significant advancements are made to exploit the unique biology of the catalytic and translocation domains. These opportunities and the status of their development will be reviewed in this chapter.
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Affiliation(s)
- John Chaddock
- Syntaxin Ltd., Units 4-10, The Quadrant, Abingdon, Oxon, OX14 3YS, UK.
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Affiliation(s)
- O Rossetto
- Department of Biomedical Sciences and National Research Council Institute of Neuroscience, University of Padova, Italy, Via G. Colombo 3, 35121 Padova, Italy
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Cheng LW, Stanker LH. Detection of botulinum neurotoxin serotypes A and B using a chemiluminescent versus electrochemiluminescent immunoassay in food and serum. J Agric Food Chem 2013; 61:755-60. [PMID: 23265581 PMCID: PMC3598631 DOI: 10.1021/jf3041963] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Botulinum neurotoxins (BoNTs) are some of the most potent biological toxins. High-affinity monoclonal antibodies (mAbs) have been developed for the detection of BoNT serotypes A and B using a chemiluminescent capture enzyme-linked immunosorbent assay (ELISA). In an effort to improve toxin detection levels in complex matrices such as food and sera, we evaluated the performance of existing antitoxin mAbs using a new electrochemiluminescence (ECL) immunoassay platform developed by Meso Scale Discovery. In side-by-side comparisons, the limits of detection (LODs) observed for ELISA and the ECL immunoassay for BoNT/A were 12 and 3 pg/mL, and for BoNT/B, they were 17 and 13 pg/mL, respectively. Both the ELISA and the ECL method were more sensitive than the "gold standard" mouse bioassay. The ECL assay outperformed ELISA in detection sensitivity in most of the food matrices fortified with BoNT/A and in some foods spiked with BoNT/B. Both the ELISA and the ECL immunoassay platforms are fast, simple alternatives for use in the routine detection of BoNTs in food and animal sera.
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Affiliation(s)
- Luisa W. Cheng
- Corresponding author (L.W.C.) Tel: 510-559-6337; Fax: 510-559-5880; ; (L.H.S)
| | - Larry H. Stanker
- Corresponding author (L.W.C.) Tel: 510-559-6337; Fax: 510-559-5880; ; (L.H.S)
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41
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Samul D, Worsztynowicz P, Leja K, Grajek W. Beneficial and harmful roles of bacteria from the Clostridium genus. Acta Biochim Pol 2013; 60:515-521. [PMID: 24432307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/02/2013] [Accepted: 12/05/2013] [Indexed: 06/03/2023]
Abstract
Bacteria of the Clostridium genus are often described only as a biological threat and a foe of mankind. However, many of them have positive properties and thanks to them they may be used in many industry branches (e.g., in solvents and alcohol production, in medicine, and also in esthetic cosmetology). During the last 10 years interest in application of C. botulinum and C. tetani in medicine significantly increased. Currently, the structure and biochemical properties of neurotoxins produced by these bacterial species, as well as possibilities of application of such toxins as botulinum as a therapeutic factor in humans, are being intensely researched. The main aim of this article is to demonstrate that bacteria from Clostridium spp. are not only pathogens and the enemy of humanity but they also have many important beneficial properties which make them usable among many chemical, medical, and cosmetic applications.
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Affiliation(s)
- Dorota Samul
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, Poznań, Poland
| | - Paulina Worsztynowicz
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, Poznań, Poland
| | - Katarzyna Leja
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, Poznań, Poland
| | - Włodzimierz Grajek
- Department of Biotechnology and Food Microbiology, Poznań University of Life Sciences, Poznań, Poland
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Abstract
Botulinum neurotoxins are used clinically for conditions characterized by hyperexcitability of peripheral nerve terminals and hypersecretory syndromes. These neurotoxins are synthesized as precursor proteins with low activity, but their effects are mediated by the active form of the neurotoxin through a multistep mechanism. Following a high-affinity interaction with a protein receptor and polysialogangliosides on the synaptic membrane, botulinum neurotoxins enter the neuron and causes a sustained inhibition of synaptic transmission. The active neurotoxin is part of a high-molecular-weight complex that protects the neurotoxin from proteolytic degradation. Although complexing proteins do not affect diffusion of therapeutic neurotoxin, they may lead to the development of neutralizing antibodies that block responsiveness to it. Nerve terminal intoxication is reversible and its duration varies for different BoNT serotypes. Although it was previously assumed that botulinum neurotoxins exert effects only on the peripheral synapses, such as the neuromuscular junction, there is now substantial evidence that these neurotoxins affect neurotransmission at distal central nervous system sites as well.
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Affiliation(s)
- Ann P Tighe
- 74 Schindler Sq, Hackettstown, NJ 07840, USA
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Abstract
After botulinum toxin was initially used to treat strabismus in the 1970s, others started using it to treat movement disorders including blepharospasm, hemifacial spasm, cervical dystonia, spasmodic dysphonia, and oromandibular dystonia. It was discovered that botulinum toxin can be an effective treatment for focal movement disorders with limited side effects. Over the past three decades, various formulations of botulinum toxin have been developed and the therapeutic use of these toxins has expanded in movement disorders and beyond. We review the history and mechanism of action of botulinum toxin, as well as describe different formulations available and their potential therapeutic uses in movement disorders.
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Affiliation(s)
- Mary Ann Thenganatt
- Department of Neurology, College of Physicians and Surgeons, Columbia University, 710 West 168th Street, New York, NY 10032, USA.
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Chen C, Wang S, Wang H, Mao X, Zhang T, Ji G, Shi X, Xia T, Lu W, Zhang D, Dai J, Guo Y. Potent neutralization of botulinum neurotoxin/B by synergistic action of antibodies recognizing protein and ganglioside receptor binding domain. PLoS One 2012; 7:e43845. [PMID: 22952786 PMCID: PMC3430616 DOI: 10.1371/journal.pone.0043845] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/26/2012] [Indexed: 11/27/2022] Open
Abstract
Background Botulinum neurotoxins (BoNTs), the causative agents for life-threatening human disease botulism, have been recognized as biological warfare agents. Monoclonal antibody (mAb) therapeutics hold considerable promise as BoNT therapeutics, but the potencies of mAbs against BoNTs are usually less than that of polyclonal antibodies (or oligoclonal antibodies). The confirmation of key epitopes with development of effective mAb is urgently needed. Methods and Findings We selected 3 neutralizing mAbs which recognize different non-overlapping epitopes of BoNT/B from a panel of neutralizing antibodies against BoNT/B. By comparing the neutralizing effects among different combination groups, we found that 8E10, response to ganglioside receptor binding site, could synergy with 5G10 and 2F4, recognizing non-overlapping epitopes within Syt II binding sites. However, the combination of 5G10 with 2F4 blocking protein receptor binding sites did not achieve synergistical effects. Moreover, we found that the binding epitope of 8E10 was conserved among BoNT A, B, E, and F, which might cross-protect the challenge of different serotypes of BoNTs in vivo. Conclusions The combination of two mAbs recognizing different receptors' binding domain in BoNTs has a synergistic effect. 8E10 is a potential universal partner for the synergistical combination with other mAb against protein receptor binding domain in BoNTs of other serotypes.
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Affiliation(s)
- Changchun Chen
- School of Pharmacy, The Center for Antibody Medicine of Ministry of Education, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Shuhui Wang
- School of Pharmacy, The Center for Antibody Medicine of Ministry of Education, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Huajing Wang
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Xiaoyan Mao
- Lanzhou Institute of Biological Products, Lanzhou, Gansu, People's Republic of China
| | - Tiancheng Zhang
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Guanghui Ji
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Xin Shi
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Tian Xia
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Weijia Lu
- Lanzhou Institute of Biological Products, Lanzhou, Gansu, People's Republic of China
| | - Dapeng Zhang
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
| | - Jianxin Dai
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
- PLA General Hospital Cancer Center, Beijing, People's Republic of China
- * E-mail: (JXD); (YJG)
| | - Yajun Guo
- International Joint Cancer Institute, The Second Military Medical University, Shanghai, People's Republic of China
- National Engineering Research Center for Antibody Medicine, State Key Laboratory of Antibody Medicine and Targeting Therapy and Shanghai Key Laboratory of Cell Engineering, Shanghai, People's Republic of China
- PLA General Hospital Cancer Center, Beijing, People's Republic of China
- * E-mail: (JXD); (YJG)
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Oguma K, Yamamoto Y, Suzuki T, Fatmawati NND, Fujita K. [Botulism: structure and function of botulinum toxin and its clinical application]. Nihon Rinsho 2012; 70:1329-1337. [PMID: 22894067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Clostridium botulinum produces seven immunological distinct poisonous neurotoxins, A to G, with molecular masses of approximately 150kDa. In acidic foods and culture fluid, the neurotoxins associate with non-toxic components, and form large complexes designated progenitor toxins. The progenitor toxins are found in three forms named LL, L, and M. These neurotoxins and progenitor toxins were purified, and whole nucleotide sequences of their structure genes were determined. In this manuscript, the structure and function of these toxins, and the application of these toxins to clinical usage have been described.
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Affiliation(s)
- Keiji Oguma
- Department of Bacteriology, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
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Masuyer G, Stancombe P, Chaddock JA, Acharya KR. Structures of engineered Clostridium botulinum neurotoxin derivatives. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:1466-72. [PMID: 22139146 PMCID: PMC3232119 DOI: 10.1107/s1744309111034671] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 08/23/2011] [Indexed: 11/10/2022]
Abstract
Targeted secretion inhibitors (TSIs) are a new class of engineered biopharmaceutical molecules derived from the botulinum neurotoxins (BoNTs). They consist of the metalloprotease light chain (LC) and translocation domain (Hn) of BoNT; they thus lack the native toxicity towards motor neurons but are able to target soluble N-ethylmaleimide-sensitive fusion protein attachment receptor (SNARE) proteins. These functional fragment (LHn) derivatives are expressed as single-chain proteins and require post-translational activation into di-chain molecules for function. A range of BoNT derivatives have been produced to demonstrate the successful use of engineered SNARE substrate peptides at the LC-Hn interface that gives these molecules self-activating capabilities. Alternatively, recognition sites for specific exoproteases can be engineered to allow controlled activation. Here, the crystal structures of three LHn derivatives are reported between 2.7 and 3.0 Å resolution. Two of these molecules are derivatives of serotype A that contain a SNARE peptide. Additionally, a third structure corresponds to LHn serotype B that includes peptide linkers at the exoprotease activation site. In all three cases the added engineered segments could not be modelled owing to disorder. However, these structures highlight the strong interactions holding the LHn fold together despite the inclusion of significant polypeptide sequences at the LC-Hn interface.
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Affiliation(s)
- Geoffrey Masuyer
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
| | - Patrick Stancombe
- Syntaxin Limited, Units 4–10, The Quadrant, Barton Lane, Abingdon, Oxon OX14 3YS, England
| | - John A. Chaddock
- Syntaxin Limited, Units 4–10, The Quadrant, Barton Lane, Abingdon, Oxon OX14 3YS, England
| | - K. Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, England
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Bosch DE, Wittchen ES, Qiu C, Burridge K, Siderovski DP. Unique structural and nucleotide exchange features of the Rho1 GTPase of Entamoeba histolytica. J Biol Chem 2011; 286:39236-46. [PMID: 21930699 PMCID: PMC3234748 DOI: 10.1074/jbc.m111.253898] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 09/13/2011] [Indexed: 01/28/2023] Open
Abstract
The single-celled human parasite Entamoeba histolytica possesses a dynamic actin cytoskeleton vital for its intestinal and systemic pathogenicity. The E. histolytica genome encodes several Rho family GTPases known to regulate cytoskeletal dynamics. EhRho1, the first family member identified, was reported to be insensitive to the Rho GTPase-specific Clostridium botulinum C3 exoenzyme, raising the possibility that it may be a misclassified Ras family member. Here, we report the crystal structures of EhRho1 in both active and inactive states. EhRho1 is activated by a conserved switch mechanism, but diverges from mammalian Rho GTPases in lacking a signature Rho insert helix. EhRho1 engages a homolog of mDia, EhFormin1, suggesting a role in mediating serum-stimulated actin reorganization and microtubule formation during mitosis. EhRho1, but not a constitutively active mutant, interacts with a newly identified EhRhoGDI in a prenylation-dependent manner. Furthermore, constitutively active EhRho1 induces actin stress fiber formation in mammalian fibroblasts, thereby identifying it as a functional Rho family GTPase. EhRho1 exhibits a fast rate of nucleotide exchange relative to mammalian Rho GTPases due to a distinctive switch one isoleucine residue reminiscent of the constitutively active F28L mutation in human Cdc42, which for the latter protein, is sufficient for cellular transformation. Nonconserved, nucleotide-interacting residues within EhRho1, revealed by the crystal structure models, were observed to contribute a moderating influence on fast spontaneous nucleotide exchange. Collectively, these observations indicate that EhRho1 is a bona fide member of the Rho GTPase family, albeit with unique structural and functional aspects compared with mammalian Rho GTPases.
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Affiliation(s)
| | | | | | - Keith Burridge
- Lineberger Comprehensive Cancer Center and
- the Department of Cell and Developmental Biology
- University of North Carolina McAllister Heart Institute, The University of North Carolina, Chapel Hill, North Carolina 27599-7365
| | - David P. Siderovski
- From the Department of Pharmacology
- University of North Carolina Neuroscience Center
- Lineberger Comprehensive Cancer Center and
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Atassi MZ, Jankovic J, Steward LE, Aoki KR, Dolimbek BZ. Molecular immune recognition of botulinum neurotoxin B. The light chain regions that bind human blocking antibodies from toxin-treated cervical dystonia patients. Antigenic structure of the entire BoNT/B molecule. Immunobiology 2011; 217:17-27. [PMID: 21962573 DOI: 10.1016/j.imbio.2011.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 08/15/2011] [Accepted: 08/21/2011] [Indexed: 11/18/2022]
Abstract
We recently mapped the regions on the heavy (H) chain of botulinum neurotoxin, type B (BoNT/B) recognized by blocking antibodies (Abs) from cervical dystonia (CD) patients who develop immunoresistance during toxin treatment. Since blocking could also be effected by Abs directed against regions on the light (L) chain, we have mapped here the L chain, using the same 30 CD antisera. We synthesized, purified and characterized 32 19-residue L chain peptides that overlapped successively by 5 residues (peptide L32 overlapped with peptide N1 of the H chain by 12 residues). In a given patient, Abs against the L chain seemed less intense than those against H chain. Most sera recognized a limited set of L chain peptides. The levels of Abs against a given region varied with the patient, consistent with immune responses to each epitope being under separate MHC control. The peptides most frequently recognized were: L13, by 30 of 30 antisera (100%); L22, by 23 of 30 (76.67%); L19, by 15 of 30 (50.00%); L26, by 11 of 30 (36.70%); and L14, by 12 of 30 (40.00%). The activity of L14 probably derives from its overlap with L13. The levels of Ab binding decreased in the following order: L13 (residues 169-187), L22 (295-313), L19 (253-271), and L26 (351-369). Peptides L12 (155-173), L18 (239-257), L15 (197-215), L1 (1-19) and L23 (309-327) exhibited very low Ab binding. The remaining peptides had little or no Ab-binding activity. The antigenic regions are analyzed in terms of their three-dimensional locations and the enzyme active site. With the previous localization of the antigenic regions on the BoNT/B H chain, the human Ab recognition of the entire BoNT/B molecule is presented and compared to the recognition of BoNT/A by human blocking Abs.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/chemistry
- Antibodies, Bacterial/immunology
- Antibodies, Blocking/blood
- Antibodies, Blocking/genetics
- Antibodies, Blocking/immunology
- Binding Sites, Antibody/genetics
- Binding Sites, Antibody/immunology
- Botulinum Toxins/administration & dosage
- Botulinum Toxins/blood
- Botulinum Toxins/chemistry
- Botulinum Toxins/immunology
- Botulinum Toxins, Type A/blood
- Botulinum Toxins, Type A/chemistry
- Botulinum Toxins, Type A/immunology
- Clostridium botulinum/chemistry
- Clostridium botulinum/immunology
- Epitope Mapping
- Humans
- Immune Sera/immunology
- Immunity, Humoral
- Mice
- Mice, Inbred ICR
- Molecular Sequence Data
- Neurotoxins/administration & dosage
- Neurotoxins/blood
- Neurotoxins/chemistry
- Neurotoxins/immunology
- Peptide Fragments/chemistry
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- Protein Binding/genetics
- Protein Binding/immunology
- Torticollis/blood
- Torticollis/drug therapy
- Torticollis/genetics
- Torticollis/immunology
- Treatment Failure
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Affiliation(s)
- M Zouhair Atassi
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States.
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Kronhardt A, Rolando M, Beitzinger C, Stefani C, Leuber M, Flatau G, Popoff MR, Benz R, Lemichez E. Cross-reactivity of anthrax and C2 toxin: protective antigen promotes the uptake of botulinum C2I toxin into human endothelial cells. PLoS One 2011; 6:e23133. [PMID: 21850257 PMCID: PMC3151279 DOI: 10.1371/journal.pone.0023133] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Accepted: 07/13/2011] [Indexed: 01/03/2023] Open
Abstract
Binary toxins are among the most potent bacterial protein toxins performing a cooperative mode of translocation and exhibit fatal enzymatic activities in eukaryotic cells. Anthrax and C2 toxin are the most prominent examples for the AB7/8 type of toxins. The B subunits bind both host cell receptors and the enzymatic A polypeptides to trigger their internalization and translocation into the host cell cytosol. C2 toxin is composed of an actin ADP-ribosyltransferase (C2I) and C2II binding subunits. Anthrax toxin is composed of adenylate cyclase (EF) and MAPKK protease (LF) enzymatic components associated to protective antigen (PA) binding subunit. The binding and translocation components anthrax protective antigen (PA63) and C2II of C2 toxin share a sequence homology of about 35%, suggesting that they might substitute for each other. Here we show by conducting in vitro measurements that PA63 binds C2I and that C2II can bind both EF and LF. Anthrax edema factor (EF) and lethal factor (LF) have higher affinities to bind to channels formed by C2II than C2 toxin's C2I binds to anthrax protective antigen (PA63). Furthermore, we could demonstrate that PA in high concentration has the ability to transport the enzymatic moiety C2I into target cells, causing actin modification and cell rounding. In contrast, C2II does not show significant capacity to promote cell intoxication by EF and LF. Together, our data unveiled the remarkable flexibility of PA in promoting C2I heterologous polypeptide translocation into cells.
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Affiliation(s)
| | - Monica Rolando
- Inserm, U895, Toxines Microbiennes dans la Relation Hôte-Pathogènes, Batiment Archimed, Nice, France
- Faculté de Médecine, Institut Fédératif de Recherche 50, Université de Nice-Sophia Antipolis, Nice, France
| | | | - Caroline Stefani
- Inserm, U895, Toxines Microbiennes dans la Relation Hôte-Pathogènes, Batiment Archimed, Nice, France
| | - Michael Leuber
- Rudolf-Virchow-Center, University of Würzburg, Würzburg, Germany
| | - Gilles Flatau
- Inserm, U895, Toxines Microbiennes dans la Relation Hôte-Pathogènes, Batiment Archimed, Nice, France
| | - Michel R. Popoff
- Unité des Bactéries Anaerobies et Toxines, Institut Pasteur, Paris, France
| | - Roland Benz
- Rudolf-Virchow-Center, University of Würzburg, Würzburg, Germany
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
- * E-mail: (EL); (RB)
| | - Emmanuel Lemichez
- Inserm, U895, Toxines Microbiennes dans la Relation Hôte-Pathogènes, Batiment Archimed, Nice, France
- Faculté de Médecine, Institut Fédératif de Recherche 50, Université de Nice-Sophia Antipolis, Nice, France
- Laboratoire central de bactériologie, Centre Hospitalier Universitaire de Nice, Nice, France
- * E-mail: (EL); (RB)
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50
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Thanongsaksrikul J, Chaicumpa W. Botulinum neurotoxins and botulism: a novel therapeutic approach. Toxins (Basel) 2011; 3:469-88. [PMID: 22069720 PMCID: PMC3202833 DOI: 10.3390/toxins3050469] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 04/22/2011] [Accepted: 04/28/2011] [Indexed: 01/01/2023] Open
Abstract
Specific treatment is not available for human botulism. Current remedial mainstay is the passive administration of polyclonal antibody to botulinum neurotoxin (BoNT) derived from heterologous species (immunized animal or mouse hybridoma) together with supportive and symptomatic management. The antibody works extracellularly, probably by blocking the binding of receptor binding (R) domain to the neuronal receptors; thus inhibiting cellular entry of the holo-BoNT. The antibody cannot neutralize the intracellular toxin. Moreover, a conventional antibody with relatively large molecular size (150 kDa) is not accessible to the enzymatic groove and, thus, cannot directly inhibit the BoNT zinc metalloprotease activity. Recently, a 15-20 kDa single domain antibody (V(H)H) that binds specifically to light chain of BoNT serotype A was produced from a humanized-camel VH/V(H)H phage display library. The V(H)H has high sequence homology (>80%) to the human VH and could block the enzymatic activity of the BoNT. Molecular docking revealed not only the interface binding between the V(H)H and the toxin but also an insertion of the V(H)H CDR3 into the toxin enzymatic pocket. It is envisaged that, by molecular linking the V(H)H to a cell penetrating peptide (CPP), the CPP-V(H)H fusion protein would be able to traverse the hydrophobic cell membrane into the cytoplasm and inhibit the intracellular BoNT. This presents a novel and safe immunotherapeutic strategy for botulism by using a cell penetrating, humanized-single domain antibody that inhibits the BoNT by means of a direct blockade of the groove of the menace enzyme.
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Affiliation(s)
- Jeeraphong Thanongsaksrikul
- Laboratory for Research and Technology Development, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkok-noi, Bangkok 10700, Thailand.
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