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09:12
A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection
Published on: June 15, 2018
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Structure of the full-length Clostridium difficile toxin B
Peng Chen1, Kwok-Ho Lam1, Zheng Liu1
1Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA.
Nature Structural & Molecular Biology
|July 17, 2019
Summary
Researchers determined the crystal structure of Clostridium difficile toxin B (TcdB) holotoxin, revealing its dynamic nature and potential vulnerabilities. This structural insight aids in developing new treatments for C. difficile infection (CDI).
Area of Science:
- Microbiology and Immunology
- Structural Biology
- Infectious Diseases
Background:
- Clostridium difficile (C. diff) is an opportunistic pathogen causing infections when gut microbiota are disrupted.
- C. diff infection (CDI) is primarily mediated by the toxins TcdA and TcdB.
- Understanding TcdB holotoxin structure is crucial for developing targeted therapies.
Purpose of the Study:
- To elucidate the high-resolution crystal structure of TcdB holotoxin.
- To investigate the dynamic conformational states of the TcdB CROPs domain.
- To characterize TcdB-antibody interactions for potential therapeutic strategies.
Main Methods:
- X-ray crystallography to determine the 3.87-Å resolution structure of TcdB holotoxin.
- Biophysical studies to analyze the dynamics of the C-terminal combined repetitive oligopeptides (CROPs) domain.
- Co-crystallization of TcdB with neutralizing antibodies to determine complex structures.
Main Results:
- A unique conformation of TcdB holotoxin at endosomal pH was captured.
- The CROPs domain exhibits dynamic sampling of open and closed conformations.
- Three distinct TcdB-antibody complex structures reveal specific inhibition mechanisms.
Conclusions:
- The study provides novel structural insights into TcdB holotoxin function during intoxication.
- The dynamic nature of the CROPs domain suggests a mechanism for activity modulation.
- Identified antibody binding sites offer potential targets for new CDI therapeutics and vaccines.
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