Cryo-EM structures reveal translocational unfolding in the clostridial binary iota toxin complex

2020 ◽  
Vol 27 (3) ◽  
pp. 288-296 ◽  
Author(s):  
Tomohito Yamada ◽  
Toru Yoshida ◽  
Akihiro Kawamoto ◽  
Kaoru Mitsuoka ◽  
Kenji Iwasaki ◽  
...  
Keyword(s):  
Toxin Complex

scholarly journals Looking for the X Factor in Bacterial Pathogenesis: Association of orfX-p47 Gene Clusters with Toxin Genes in Clostridial and Non-Clostridial Bacterial Species

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 19 ◽  
Author(s):  
Maria B. Nowakowska ◽  
François P. Douillard ◽  
Miia Lindström
Keyword(s):  
Gene Cluster ◽  
In Silico ◽  
Botulinum Neurotoxin ◽  
Bacterial Species ◽  
Gene Clusters ◽  
Bacterial Pathogenesis ◽  
Toxin Gene ◽  
Toxin Complex ◽  
Analytical Tools ◽  
Bacillus Isolate

The botulinum neurotoxin (BoNT) has been extensively researched over the years in regard to its structure, mode of action, and applications. Nevertheless, the biological roles of four proteins encoded from a number of BoNT gene clusters, i.e., OrfX1-3 and P47, are unknown. Here, we investigated the diversity of orfX-p47 gene clusters using in silico analytical tools. We show that the orfX-p47 cluster was not only present in the genomes of BoNT-producing bacteria but also in a substantially wider range of bacterial species across the bacterial phylogenetic tree. Remarkably, the orfX-p47 cluster was consistently located in proximity to genes coding for various toxins, suggesting that OrfX1-3 and P47 may have a conserved function related to toxinogenesis and/or pathogenesis, regardless of the toxin produced by the bacterium. Our work also led to the identification of a putative novel BoNT-like toxin gene cluster in a Bacillus isolate. This gene cluster shares striking similarities to the BoNT cluster, encoding a bont/ntnh-like gene and orfX-p47, but also differs from it markedly, displaying additional genes putatively encoding the components of a polymorphic ABC toxin complex. These findings provide novel insights into the biological roles of OrfX1, OrfX2, OrfX3, and P47 in toxinogenesis and pathogenesis of BoNT-producing and non-producing bacteria.

Expression and stability of the nontoxic component of the botulinum toxin complex

2009 ◽  
Vol 384 (1) ◽  
pp. 126-130 ◽  
Author(s):  
Keita Miyata ◽  
Tohru Yoneyama ◽  
Tomonori Suzuki ◽  
Hirokazu Kouguchi ◽  
Ken Inui ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Toxin Complex

scholarly journals Role of nontoxic components of serotype D botulinum toxin complex in permeation through a Caco-2 cell monolayer, a model for intestinal epithelium

2007 ◽  
Vol 49 (3) ◽  
pp. 346-352 ◽  
Author(s):  
Koichi Niwa ◽  
Kumiko Koyama ◽  
Shin-ichi Inoue ◽  
Tomonori Suzuki ◽  
Kimiko Hasegawa ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Intestinal Epithelium ◽  
Cell Monolayer ◽  
Toxin Complex

scholarly journals Atomistic Analysis of ToxN and ToxI Complex Unbinding Mechanism

2018 ◽  
Vol 19 (11) ◽  
pp. 3524 ◽  
Author(s):  
Guodong Hu ◽  
Xiu Yu ◽  
Yunqiang Bian ◽  
Zanxia Cao ◽  
Shicai Xu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Noncoding Rna ◽  
Md Simulations ◽  
Normal Function ◽  
Toxin Complex ◽  
Potentials Of Mean Force ◽  
Protein Toxins ◽  
Function Relationship ◽  
The Stability ◽  
Smd Simulations

ToxIN is a triangular structure formed by three protein toxins (ToxNs) and three specific noncoding RNA antitoxins (ToxIs). To respond to stimuli, ToxI is preferentially degraded, releasing the ToxN. Thus, the dynamic character is essential in the normal function interactions between ToxN and ToxI. Here, equilibrated molecular dynamics (MD) simulations were performed to study the stability of ToxN and ToxI. The results indicate that ToxI adjusts the conformation of 3′ and 5′ termini to bind to ToxN. Steered molecular dynamics (SMD) simulations combined with the recently developed thermodynamic integration in 3nD (TI3nD) method were carried out to investigate ToxN unbinding from the ToxIN complex. The potentials of mean force (PMFs) and atomistic pictures suggest the unbinding mechanism as follows: (1) dissociation of the 5′ terminus from ToxN, (2) missing the interactions involved in the 3′ terminus of ToxI without three nucleotides (G31, A32, and A33), (3) starting to unfold for ToxI, (4) leaving the binding package of ToxN for three nucleotides of ToxI, (5) unfolding of ToxI. This work provides information on the structure-function relationship at the atomistic level, which is helpful for designing new potent antibacterial drugs in the future.

scholarly journals Efficacy of a Potential Trivalent Vaccine Based on Hc Fragments of Botulinum Toxins A, B, and E Produced in a Cell-Free Expression System

2010 ◽  
Vol 17 (5) ◽  
pp. 784-792 ◽  
Author(s):  
R. Zichel ◽  
A. Mimran ◽  
A. Keren ◽  
A. Barnea ◽  
I. Steinberger-Levy ◽  
...  
Keyword(s):  
Expression System ◽  
Free Expression ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Dose ◽  
Botulinum Toxins ◽  
Free System ◽  
Toxin Complex ◽  
A Cell ◽  
Cell Free Expression System

ABSTRACT Botulinum toxins produced by the anaerobic bacterium Clostridium botulinum are the most potent biological toxins in nature. Traditionally, people at risk are immunized with a formaldehyde-inactivated toxin complex. Second generation vaccines are based on the recombinant carboxy-terminal heavy-chain (Hc) fragment of the neurotoxin. However, the materialization of this approach is challenging, mainly due to the high AT content of clostridial genes. Herein, we present an alternative strategy in which the native genes encoding Hc proteins of botulinum toxins A, B, and E were used to express the recombinant Hc fragments in a cell-free expression system. We used the unique property of this open system to introduce different combinations of chaperone systems, protein disulfide isomerase (PDI), and reducing/oxidizing environments directly to the expression reaction. Optimized expression conditions led to increased production of soluble Hc protein, which was successfully scaled up using a continuous exchange (CE) cell-free system. Hc proteins were produced at a concentration of more than 1 mg/ml and purified by one-step Ni+ affinity chromatography. Mice immunized with three injections containing 5 μg of any of the in vitro-expressed, alum-absorbed, Hc vaccines generated a serum enzyme-linked immunosorbent assay (ELISA) titer of 105 against the native toxin complex, which enabled protection against a high-dose toxin challenge (103 to 106 mouse 50% lethal dose [MsLD50]). Finally, immunization with a trivalent HcA, HcB, and HcE vaccine protected mice against the corresponding trivalent 105 MsLD50 toxin challenge. Our results together with the latest developments in scalability of the in vitro protein expression systems offer alternative routes for the preparation of botulinum vaccine.

scholarly journals Gambaran Umum, Prevalensi, dan Pencegahan Antraks pada Manusia di Indonesia

2020 ◽  
pp. 135-148
Author(s):  
Ihda Zuyina Ratna Sari ◽  
Silvia Apriliana
Keyword(s):  
Social Economic ◽  
Economic Conditions ◽  
Public Knowledge ◽  
Health Official ◽  
The People ◽  
Global Issue ◽  
Standard Operating ◽  
Toxin Complex ◽  
Cutaneous Anthrax ◽  
And Control

Anthrax is a neglected zoonotic disease that remains a global issue because it can cause regular epidemics. Anthrax affects not only health systems but also social-economic conditions, safety, and welfare of the people. This paper aimed to give an overview of human anthrax, prevalence, and prevention in Indonesia. A literature search was performed using search engines such as Google Scholar, Crossref, Mendeley, PLoS One, Elsevier, dan the Ministry of Health official website. The literature used were published between 2015-2020. Anthrax is caused by Bacillus anthracis that affects animals and humans. The virulence factors of these bacteria are determined by the tripartite toxin complex and poly-γ-D-glutamic acid capsule. Anthrax in humans can be found in four forms, namely cutaneous, gastrointestinal, inhalational, and injection anthrax. Each form of anthrax can develop into meningitis and sepsis. Anthrax treatment is commonly done by administering antibiotics. In Indonesia, 14 provinces have been declared anthrax endemic areas. The prevalence of human anthrax in Indonesia is fluctuating and most of it is cutaneous anthrax. Prevention and control of anthrax can be done mainly by vaccination, obeying the rules or standard operating procedures of the authorities, multisectoral cooperation, strengthening anthrax surveillance, increasing resources for diagnosis, increasing public knowledge, and awareness.

scholarly journals Botulinum Toxin Complex: A Delivery Vehicle of Botulinum Neurotoxin Traveling Digestive Tract

10.5772/46023 ◽  
2012 ◽  
Author(s):  
Yoshimasa Sagane ◽  
Ken Inui ◽  
Shin-Ichiro Miyashita ◽  
Keita Miyata ◽  
Tomonori Suzuki ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Digestive Tract ◽  
Botulinum Neurotoxin ◽  
Delivery Vehicle ◽  
Toxin Complex

Purification and Characterization of a High-Molecular-Weight Insecticidal Protein Complex Produced by the Entomopathogenic BacteriumPhotorhabdus luminescens

1998 ◽  
Vol 64 (8) ◽  
pp. 3029-3035 ◽  
Author(s):  
David J. Bowen ◽  
Jerald C. Ensign
Keyword(s):  
Molecular Weight ◽  
Insecticidal Activity ◽  
Protein Complex ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Protein Toxin ◽  
The Family ◽  
Toxin Complex

ABSTRACT Photorhabdus luminescens is a gram-negative enteric bacterium that is found in association with entomopathogenic nematodes of the family Heterorhabditidae. The nematodes infect a variety of soil-dwelling insects. Upon entering an insect host, the nematode releases P. luminescens cells from its intestinal tract, and the bacteria quickly establish a lethal septicemia. When grown in peptone broth, in the absence of the nematodes, the bacteria produce a protein toxin complex that is lethal when fed to, or injected into the hemolymph of, Manduca sexta larvae and several other insect species. The toxin purified as a protein complex which has an estimated molecular weight of 1,000,000 and contains no protease, phospholipase, or hemolytic activity and only a trace of lipase activity. The purified toxin possesses insecticidal activity whether injected or given orally. Analyses of the denatured complex by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed it to be composed of several protein subunits ranging in size from 30 to 200 kDa. The complex was further separated by native gel electrophoresis into three components, two of which retained insecticidal activity. The purified native toxin complex was found to be active in nanogram concentrations against insects representing four orders of the classInsecta.

scholarly journals Botulinum and Tetanus Neurotoxins

2019 ◽  
Vol 88 (1) ◽  
pp. 811-837 ◽  
Author(s):  
Min Dong ◽  
Geoffrey Masuyer ◽  
Pål Stenmark
Keyword(s):  
Motor Neurons ◽  
Host Proteins ◽  
Tetanus Neurotoxin ◽  
Synaptic Vesicle Exocytosis ◽  
Receptor Recognition ◽  
Toxin Complex ◽  
Vesicle Exocytosis ◽  
Botulinum Neurotoxins ◽  
Distinct Features ◽  
Progenitor Toxin

Botulinum neurotoxins (BoNTs) and tetanus neurotoxin (TeNT) are the most potent toxins known and cause botulism and tetanus, respectively. BoNTs are also widely utilized as therapeutic toxins. They contain three functional domains responsible for receptor-binding, membrane translocation, and proteolytic cleavage of host proteins required for synaptic vesicle exocytosis. These toxins also have distinct features: BoNTs exist within a progenitor toxin complex (PTC), which protects the toxin and facilitates its absorption in the gastrointestinal tract, whereas TeNT is uniquely transported retrogradely within motor neurons. Our increasing knowledge of these toxins has allowed the development of engineered toxins for medical uses. The discovery of new BoNTs and BoNT-like proteins provides additional tools to understand the evolution of the toxins and to engineer toxin-based therapeutics. This review summarizes the progress on our understanding of BoNTs and TeNT, focusing on the PTC, receptor recognition, new BoNT-like toxins, and therapeutic toxin engineering.

Sign in / Sign up

Export Citation Format

Share Document