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Gao L, Lam KH, Liu S, Przykopanski A, Lübke J, Qi R, Krüger M, Nowakowska MB, Selby K, Douillard FP, Dorner MB, Perry K, Lindström M, Dorner BG, Rummel A, Jin R. Crystal structures of OrfX1, OrfX2 and the OrfX1-OrfX3 complex from the orfX gene cluster of botulinum neurotoxin E1. FEBS Lett 2023; 597:524-537. [PMID: 36653893 PMCID: PMC10019085 DOI: 10.1002/1873-3468.14576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 01/20/2023]
Abstract
Botulinum neurotoxins (BoNTs) are among the most lethal toxins known to humans, comprising seven established serotypes termed BoNT/A-G encoded in two types of gene clusters (ha and orfX) in BoNT-producing clostridia. The ha cluster encodes four non-toxic neurotoxin-associated proteins (NAPs) that assemble with BoNTs to protect and enhance their oral toxicity. However, the structure and function of the orfX-type NAPs remain largely unknown. Here, we report the crystal structures for OrfX1, OrfX2, and an OrfX1-OrfX3 complex, which are encoded in the orfX cluster of a BoNT/E1-producing Clostridium botulinum strain associated with human foodborne botulism. These structures lay the foundation for future studies on the potential roles of OrfX proteins in oral intoxication and pathogenesis of BoNTs.
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Affiliation(s)
- Linfeng Gao
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Kwok-ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Shun Liu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Adina Przykopanski
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Johanna Lübke
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Ruifeng Qi
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
| | - Maren Krüger
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany
| | - Maria B. Nowakowska
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, P. O. Box 66, 00014 University of Helsinki, Finland
| | - Katja Selby
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, P. O. Box 66, 00014 University of Helsinki, Finland
| | - François P. Douillard
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, P. O. Box 66, 00014 University of Helsinki, Finland
| | - Martin B. Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, P. O. Box 66, 00014 University of Helsinki, Finland
| | - Brigitte G. Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany
| | - Andreas Rummel
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
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Tulin EKC, Yoshimura T, Nakazawa C, Saito S, Kanai K, Kozono T, Nakakita SI, Tonozuka T, Ikenaka K, Nishikawa A. Recombinant lectin Gg for brain imaging of glycan structure and formation in the CNS node of Ranvier. J Neurochem 2022; 163:461-477. [PMID: 36156798 DOI: 10.1111/jnc.15695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/12/2022] [Accepted: 09/13/2022] [Indexed: 01/19/2023]
Abstract
The nodes of Ranvier are unmyelinated gaps in the axon, important for the efficient transmission of action potentials. Despite the identification of several glycoproteins involved in node formation and maintenance, glycans' structure and formation in the node remain unclear. Previously, we developed a recombinant lectin from the Clostridium botulinum neurotoxin complex, specific to the galactose and N-acetylgalactosamine terminal epitopes (Gg). Gg stained Neuro2a cells. Here, we show Gg punctuate staining in mouse brain cryosections. Thus, we hypothesized that Gg could help study glycans in the node of Ranvier. Lectin histochemistry on mouse brain cryosections confirmed that Gg binds specifically to the node of Ranvier in the central nervous system (CNS). Using a combination of lectin blotting, glycosidase treatment on tissue sections, and lectin histochemistry, Gg ligands were identified as α-galactose terminal glycoproteins in the perinodal extracellular matrix. Furthermore, we detected the spatiotemporal distribution of galactosylated glycans in the CNS node of Ranvier in mouse brain tissues at different postnatal times. Finally, we observed impaired clustering of galactosylated glycans in the nodes during demyelination and remyelination in cuprizone-induced demyelination and remyelination mouse model. In conclusion, Gg can serve as a novel brain imaging tool in glycobiology and report glycoprotein formation and alterations in the CNS node of Ranvier. Our findings might serve as a first step to establish the role of glycans in the node of Ranvier.
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Affiliation(s)
- Ea Kristine Clarisse Tulin
- Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Chiaki Nakazawa
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Shion Saito
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Kyoko Kanai
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Takuma Kozono
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | | | - Takashi Tonozuka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Atsushi Nishikawa
- Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.,Department of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
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Glycan detecting tools developed from the Clostridium botulinum whole hemagglutinin complex. Sci Rep 2021; 11:21973. [PMID: 34754033 PMCID: PMC8578614 DOI: 10.1038/s41598-021-01501-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/25/2021] [Indexed: 01/24/2023] Open
Abstract
Lectins are proteins with the ability to recognize and bind to specific glycan structures. These molecules play important roles in many biological systems and are actively being studied because of their ability to detect glycan biomarkers for many diseases. Hemagglutinin (HA) proteins from Clostridium botulinum type C neurotoxin complex; HA1, HA2, and HA3 are lectins that aid in the internalization of the toxin complex by binding to glycoproteins on the cell surface. HA1 mutants have been previously reported, namely HA1 W176A/D271F and HA1 N278A/Q279A which are specific to galactose (Gal)/N-acetylgalactosamine (GalNAc) and N-acetylneuraminic acid (Neu5Ac) sugars, respectively. In this study, we utilized HA1 mutants and expressed them in complex with HA2 WT and HA3 WT to produce glycan detecting tools with high binding affinity. Particularly, two types were made: Gg and Rn. Gg is an Alexa 488 conjugated lectin complex specific to Gal and GalNAc, while Rn is an Alexa 594 conjugated lectin complex specific to Neu5Ac. The specificities of these lectins were identified using a glycan microarray followed by competitive sugar inhibition experiments on cells. In addition, we confirmed that Gg and Rn staining is clearly different depending on cell type, and the staining pattern of these lectins reflects the glycans present on the cell surface as shown in enzyme treatment experiments. The availability of Gg and Rn provide us with new promising tools to study Gal, GalNAc, and Neu5Ac terminal epitopes which can aid in understanding the functional role of glycans in physiological and pathological events.
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Rulff R, Schrödl W, Basiouni S, Neuhaus J, Krüger M. Is downer cow syndrome related to chronic botulism? Pol J Vet Sci 2016; 18:759-65. [PMID: 26812817 DOI: 10.1515/pjvs-2015-0098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The present work was directed to investigate the relationship between Downer cow syndrome (DCS) and chronic botulism in dairy cattle. For this purpose, a total of 52 fresh calving downer cows and 206 apparently healthy cows at 14 dairy farms were investigated for Clostridium botulinum ABE and CD antibody levels, C. botulinum and botulinum neurotoxin in rumen fluids as well as in faeces. Results indicated that the downer cows had higher IgG titers for C. botulinum ABE and CD than the healthy cows. All tested rumen fluids were negative for BoNT and C. botulinum. BoNT/D, however, and C. botulinum type D spores were detected in faecal samples of healthy and downer cows in the selected farms. In conclusion, the presence of a significantly higher C. botulinum ABE and CD antibody levels in DCS cows than in the healthy animals suggests that chronic C. botulinum toxico-infection could be a predisposing factor for DCS.
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Rummel A. The long journey of botulinum neurotoxins into the synapse. Toxicon 2015; 107:9-24. [PMID: 26363288 DOI: 10.1016/j.toxicon.2015.09.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 08/27/2015] [Accepted: 09/08/2015] [Indexed: 01/09/2023]
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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Miyata K, Suzuki T, Hayashi S, Miyashita SI, Ohyama T, Niwa K, Watanabe T, Sagane Y. Hemagglutinin gene shuffling amongClostridium botulinumserotypes C and D yields distinct sugar recognition of the botulinum toxin complex. Pathog Dis 2015. [DOI: 10.1093/femspd/ftv054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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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] [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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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] [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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Srisucharitpanit K, Yao M, Promdonkoy B, Chimnaronk S, Tanaka I, Boonserm P. Crystal structure of BinB: A receptor binding component of the binary toxin from Lysinibacillus sphaericus. Proteins 2014; 82:2703-12. [DOI: 10.1002/prot.24636] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/12/2014] [Accepted: 06/18/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Kanokporn Srisucharitpanit
- Institute of Molecular Biosciences, Mahidol University; Salaya, Phuttamonthon Nakhon Pathom 73170 Thailand
- Faculty of Allied Health Science; Burapha University, Saensook; Muang District Chon Buri 20131 Thailand
| | - Min Yao
- Faculty of Advanced Life Sciences; Hokkaido University; Sapporo 060-0810 Japan
| | - Boonhiang Promdonkoy
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency; 113 Pahonyothin Road, Khlong Nueng Khlong Luang Pathum Thani 12120 Thailand
| | - Sarin Chimnaronk
- Institute of Molecular Biosciences, Mahidol University; Salaya, Phuttamonthon Nakhon Pathom 73170 Thailand
| | - Isao Tanaka
- Faculty of Advanced Life Sciences; Hokkaido University; Sapporo 060-0810 Japan
| | - Panadda Boonserm
- Institute of Molecular Biosciences, Mahidol University; Salaya, Phuttamonthon Nakhon Pathom 73170 Thailand
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Yao G, Lee K, Gu S, Lam KH, Jin R. Botulinum neurotoxin A complex recognizes host carbohydrates through its hemagglutinin component. Toxins (Basel) 2014; 6:624-35. [PMID: 24525478 PMCID: PMC3942755 DOI: 10.3390/toxins6020624] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 01/15/2014] [Accepted: 02/05/2014] [Indexed: 11/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are potent bacterial toxins. The high oral toxicity of BoNTs is largely attributed to the progenitor toxin complex (PTC), which is assembled from BoNT and nontoxic neurotoxin-associated proteins (NAPs) that are produced together with BoNT in bacteria. Here, we performed ex vivo studies to examine binding of the highly homogeneous recombinant NAPs to mouse small intestine. We also carried out the first comprehensive glycan array screening with the hemagglutinin (HA) component of NAPs. Our data confirmed that intestinal binding of the PTC is partly mediated by the HA moiety through multivalent interactions between HA and host carbohydrates. The specific HA-carbohydrate recognition could be inhibited by receptor-mimicking saccharides.
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Affiliation(s)
- Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
| | - Kwangkook Lee
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, 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.
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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11
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Efficacy of Clostridium botulinum types C and D toxoid vaccination in Danish cows. Anaerobe 2013; 23:97-101. [DOI: 10.1016/j.anaerobe.2013.06.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/24/2013] [Indexed: 11/19/2022]
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Gu S, Jin R. Assembly and function of the botulinum neurotoxin progenitor complex. Curr Top Microbiol Immunol 2013; 364:21-44. [PMID: 23239347 DOI: 10.1007/978-3-642-33570-9_2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Botulinum neurotoxins (BoNTs) are among the most poisonous substances known to man, but paradoxically, BoNT-containing medicines and cosmetics have been used with great success in the clinic. Accidental BoNT poisoning mainly occurs through oral ingestion of food contaminated with Clostridium botulinum. BoNTs are naturally produced in the form of progenitor toxin complexes (PTCs), which are high molecular weight (up to ~900 kDa) multiprotein complexes composed of BoNT and several non-toxic neurotoxin-associated proteins (NAPs). NAPs protect the inherently fragile BoNTs against the hostile environment of the gastrointestinal (GI) tract and help BoNTs pass through the intestinal epithelial barrier before they are released into the general circulation. These events are essential for ingested BoNTs to gain access to motoneurons, where they inhibit neurotransmitter release and cause muscle paralysis. In this review, we discuss the structural basis for assembly of NAPs and BoNT into the PTC that protects BoNT and facilitate its delivery into the bloodstream.
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Affiliation(s)
- Shenyan Gu
- Center for Neuroscience, Aging and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
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Yamashita S, Yoshida H, Uchiyama N, Nakakita Y, Nakakita SI, Tonozuka T, Oguma K, Nishikawa A, Kamitori S. Carbohydrate recognition mechanism of HA70 from Clostridium botulinum deduced from X-ray structures in complexes with sialylated oligosaccharides. FEBS Lett 2012; 586:2404-10. [PMID: 22684008 DOI: 10.1016/j.febslet.2012.05.055] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 05/20/2012] [Accepted: 05/26/2012] [Indexed: 10/28/2022]
Abstract
Clostridium botulinum produces the botulinum neurotoxin, forming a large complex as progenitor toxins in association with non-toxic non-hemagglutinin and/or several different hemagglutinin (HA) subcomponents, HA33, HA17 and HA70, which bind to carbohydrate of glycoproteins from epithelial cells in the infection process. To elucidate the carbohydrate recognition mechanism of HA70, X-ray structures of HA70 from type C toxin (HA70/C) in complexes with sialylated oligosaccharides were determined, and a binding assay by the glycoconjugate microarray was performed. These results suggested that HA70/C can recognize both α2-3- and α2-6-sialylated oligosaccharides, and that it has a higher affinity for α2-3-sialylated oligosaccharides.
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Affiliation(s)
- Satoshi Yamashita
- Life Science Research Center and Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Kita-gun, Kagawa 761-0793, Japan
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14
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Gu S, Jin R. Assembly and Function of the Botulinum Neurotoxin Progenitor Complex. Curr Top Microbiol Immunol 2012. [DOI: 10.1007/978-3-662-45790-0_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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15
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Nakamura T, Tonozuka T, Ito S, Takeda Y, Sato R, Matsuo I, Ito Y, Oguma K, Nishikawa A. Molecular diversity of the two sugar-binding sites of the β-trefoil lectin HA33/C (HA1) from Clostridium botulinum type C neurotoxin. Arch Biochem Biophys 2011; 512:69-77. [PMID: 21640703 DOI: 10.1016/j.abb.2011.05.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 05/19/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
Abstract
A critical role in internalizing the Clostridium botulinum neurotoxin into gastrointestinal cells is played by nontoxic components complexed with the toxin. One of the components, a β-trefoil lectin has been known as HA33 or HA1. The HA33 from C. botulinum type A (HA33/A) has been predicted to have a single sugar-binding site, while type C HA33 (HA33/C) has two sites. Here we constructed HA33/C mutants and evaluated the binding capacities of the individual sites through mucin-assay and isothermal titration calorimetry. The mutant W176A (site I knockout) had a K(d) value of 31.5mM for galactose (Gal) and 61.3mM for N-acetylgalactosamine (GalNAc), while the K(d) value for N-acetylneuraminic acid (Neu5Ac) was too high to be determined. In contrast, the double mutant N278A/Q279A (site II knockout) had a K(d) value of 11.8mM for Neu5Ac. We also determined the crystal structures of wild-type and the F179I mutant in complex with GalNAc at site II. The results suggest that site I of HA33/C is quite unique in that it mainly recognizes Neu5Ac, and site II seems less important for the lectin specificity. The architectures and the properties of the sugar-binding sites of HA33/C and HA33/A were shown to be drastically different.
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Affiliation(s)
- Toshio Nakamura
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
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Cheng LW, Henderson TD. Comparison of oral toxicological properties of botulinum neurotoxin serotypes A and B. Toxicon 2011; 58:62-7. [PMID: 21600236 DOI: 10.1016/j.toxicon.2011.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 04/27/2011] [Accepted: 05/03/2011] [Indexed: 01/26/2023]
Abstract
Botulinum neurotoxins (BoNTs) are among the most potent biological toxins for humans. Of the seven known serotypes (A-G) of BoNT, serotypes A, B and E cause most of the foodborne intoxications in humans. BoNTs in nature are associated with non-toxic accessory proteins known as neurotoxin-associated proteins (NAPs), forming large complexes that have been shown to play important roles in oral toxicity. Using mouse intraperitoneal and oral models of botulism, we determined the dose response to both BoNT/B holotoxin and complex toxins, and compared the toxicities of BoNT/B and BoNT/A complexes. Although serotype A and B complexes have similar NAP composition, BoNT/B formed larger-sized complexes, and was approximately 90 times more lethal in mouse oral intoxications than BoNT/A complexes. When normalized by mean lethal dose, mice orally treated with high doses of BoNT/B complex showed a delayed time-to-death when compared with mice treated with BoNT/A complex. Furthermore, we determined the effect of various food matrices on oral toxicity of BoNT/A and BoNT/B complexes. BoNT/B complexes showed lower oral bioavailability in liquid egg matrices when compared to BoNT/A complexes. In summary, our studies revealed several factors that can either enhance or reduce the toxicity and oral bioavailability of BoNTs. Dissecting the complexities of the different BoNT serotypes and their roles in foodborne botulism will lead to a better understanding of toxin biology and aid future food risk assessments.
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Affiliation(s)
- Luisa W Cheng
- Foodborne Contaminants Research Unit, Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
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Nakamura T, Kotani M, Tonozuka T, Ide A, Oguma K, Nishikawa A. Crystal Structure of the HA3 Subcomponent of Clostridium botulinum Type C Progenitor Toxin. J Mol Biol 2009; 385:1193-206. [DOI: 10.1016/j.jmb.2008.11.039] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2008] [Revised: 11/15/2008] [Accepted: 11/19/2008] [Indexed: 11/30/2022]
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Jin Y, Takegahara Y, Sugawara Y, Matsumura T, Fujinaga Y. Disruption of the epithelial barrier by botulinum haemagglutinin (HA) proteins – differences in cell tropism and the mechanism of action between HA proteins of types A or B, and HA proteins of type C. Microbiology (Reading) 2009; 155:35-45. [DOI: 10.1099/mic.0.021246-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Orally ingested botulinum neurotoxin (BoNT) causes food-borne botulism, but BoNT must pass through the gut lining and enter the bloodstream. We have previously found that type B haemagglutinin (HA) proteins in the toxin complex play an important role in the intestinal absorption of BoNT by disrupting the paracellular barrier of the intestinal epithelium, and therefore facilitating the transepithelial delivery of BoNT. Here, we show that type A HA proteins in the toxin complex have a similar disruptive activity and a greater potency than type B HA proteins in the human intestinal epithelial cell lines Caco-2 and T84 and in the canine kidney epithelial cell line MDCK I. In contrast, type C HA proteins in the toxin complex (up to 300 nM) have no detectable effect on the paracellular barrier in these human cell lines, but do show a barrier-disrupting activity and potent cytotoxicity in MDCK I. These findings may indicate that type A and B HA proteins contribute to the development of food-borne botulism, at least in humans, by facilitating the intestinal transepithelial delivery of BoNTs, and that the relative inability of type C HA proteins to disrupt the paracellular barrier of the human intestinal epithelium is one of the reasons for the relative absence of food-borne human botulism caused by type C BoNT.
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Affiliation(s)
- Yingji Jin
- Laboratory for Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565–0871, Japan
| | - Yuki Takegahara
- Laboratory for Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565–0871, Japan
| | - Yo Sugawara
- Laboratory for Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565–0871, Japan
| | - Takuhiro Matsumura
- Laboratory for Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565–0871, Japan
| | - Yukako Fujinaga
- Laboratory for Infection Cell Biology, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565–0871, Japan
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Bucki R, Namiot DB, Namiot Z, Savage PB, Janmey PA. Salivary mucins inhibit antibacterial activity of the cathelicidin-derived LL-37 peptide but not the cationic steroid CSA-13. J Antimicrob Chemother 2008; 62:329-35. [PMID: 18456648 DOI: 10.1093/jac/dkn176] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVES Cationic antimicrobial peptides (CAPs) are the effector molecules of innate immunity, similar in potency to classic antibiotics that function in the first-line of defence against infectious agents. The purpose of this study was to investigate the effects of negatively charged mucins on the antibacterial activity of the positively charged cathelicidin LL-37 peptide, its synthetic analogue WLBU2 and the antimicrobial cationic steroid CSA-13. METHODS Mucin, DNA, F-actin and hCAP-18/LL-37 in saliva samples were evaluated by microscopy or immunoblotting. Bacterial killing assays and determination of MICs were used to determine bactericidal activity. Binding of rhodamine-B-labelled LL-37 peptide to mucin was fluorimetrically assessed. RESULTS Microscopic evaluation of saliva after addition of rhodamine-B-labelled LL-37 showed localization similar to that observed after the addition of a specific mucin-binding lectin. Immunoblotting confirmed the presence of hCAP-18/LL-37 in saliva samples and LL-37 peptide bound to isolated submaxillary gland mucin-coated plates. Mucin/LL-37 binding was partially prevented by treatment of mucin with neuraminidase, indicating involvement of sialic acid moieties. Decreased LL-37 and WLBU2 antibacterial activity was observed in the presence of mucin or dialysed human saliva, whereas CSA-13 antibacterial activity was significantly resistant to inhibition by mucins. CONCLUSIONS This study shows that the antibacterial LL-37 peptide and its synthetic analogue WLBU2 are inhibited by salivary mucin and that the cationic steroid CSA-13 retains most of its function in the presence of an equal amount of mucin or saliva.
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Affiliation(s)
- Robert Bucki
- Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, 1010 Vagelos Research Laboratories, 3340 Smith Walk, Philadelphia, PA 19104, USA.
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Nakamura T, Tonozuka T, Ide A, Yuzawa T, Oguma K, Nishikawa A. Sugar-binding sites of the HA1 subcomponent of Clostridium botulinum type C progenitor toxin. J Mol Biol 2007; 376:854-67. [PMID: 18178224 DOI: 10.1016/j.jmb.2007.12.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 12/09/2007] [Accepted: 12/12/2007] [Indexed: 11/17/2022]
Abstract
Clostridium botulinum type C 16S progenitor toxin contains a hemagglutinin (HA) subcomponent, designated HA1, which appears to play an important role in the effective internalization of the toxin in gastrointestinal epithelial cells and in creating a broad specificity for the oligosaccharide structure that corresponds to various targets. In this study, using the recombinant protein fused to glutathione S-transferase, we investigated the binding specificity of the HA1 subcomponent to sugars and estimated the binding sites of HA1 based on X-ray crystallography and soaking experiments using various sugars. N-Acetylneuraminic acid, N-acetylgalactosamine, and galactose effectively inhibited the binding that occurs between glutathione S-transferase-HA1 and mucins, whereas N-acetylglucosamine and glucose did not inhibit it. The crystal structures of HA1 complex with N-acetylneuraminic acid, N-acetylgalactosamine, and galactose were also determined. There are two sugar-binding sites, sites I and II. Site I corresponds to the electron densities noted for all sugars and is located at the C-terminal beta-trefoil domain, while site II corresponds to the electron densities noted only for galactose. An aromatic amino acid residue, Trp176, at site I has a stacking interaction with the hexose ring of the sugars. On the other hand, there is no aromatic residue at site II; thus, the interaction with galactose seems to be poor. The double mutant W176A at site I and D271F at site II has no avidity for N-acetylneuraminic acid but has avidity for galactose. In this report, the binding specificity of botulinum C16S toxin HA1 to various sugars is demonstrated based on its structural features.
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Affiliation(s)
- Toshio Nakamura
- Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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