Repositioning small molecule drugs as allosteric inhibitors of the BFT‐3 toxin from enterotoxigenic Bacteroides fragilis

DOI: 10.1002/pro.4427

Authors: Ana Jimenez‐alesanco (Universidad de Zaragoza) , Ulrich Eckhard (Molecular Biology Institute of Barcelona (IBMB), Higher Scientific Research Council (CSIC)) , Marta Asencio Del Rio (Universidad de Zaragoza; Instituto de Investigación Sanitaria de Aragón (IIS Aragon)) , Sonia Vega (Universidad de Zaragoza) , Tibisay Guevara (Molecular Biology Institute of Barcelona (IBMB), Higher Scientific Research Council (CSIC)) , Adrian Velazquez-Campoy (Universidad de Zaragoza; Instituto de Investigación Sanitaria de Aragón (IIS Aragon); Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas Digestivas (CIBERehd)) , Francesc Xavier Gomis‐rüth (Molecular Biology Institute of Barcelona (IBMB), Higher Scientific Research Council (CSIC); University of Zaragoza) , Olga Abian (Universidad de Zaragoza; Instituto de Investigación Sanitaria de Aragón (IIS Aragon); Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas Digestivas (CIBERehd))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Protein Science , VOL 31

State: Published (Approved)
Published: October 2022

Abstract: Bacteroides fragilis is an abundant commensal component of the healthy human colon. However, under dysbiotic conditions, enterotoxigenic B. fragilis (ETBF) may arise and elicit diarrhea, anaerobic bacteremia, inflammatory bowel disease, and colorectal cancer. Most worrisome, ETBF is resistant to many disparate antibiotics. ETBF's only recognized specific virulence factor is a zinc-dependent metallopeptidase (MP) called B. fragilis toxin (BFT) or fragilysin, which damages the intestinal mucosa and triggers disease-related signaling mechanisms. Thus, therapeutic targeting of BFT is expected to limit ETBF pathogenicity and improve the prognosis for patients. We focused on one of the naturally occurring BFT isoforms, BFT-3, and managed to repurpose several approved drugs as BFT-3 inhibitors through a combination of biophysical, biochemical, structural, and cellular techniques. In contrast to canonical MP inhibitors, which target the active site of mature enzymes, these effectors bind to a distal allosteric site in the proBFT-3 zymogen structure, which stabilizes a partially unstructured, zinc-free enzyme conformation by shifting a zinc-dependent disorder-to-order equilibrium. This yields proBTF-3 incompetent for autoactivation, thus ablating hydrolytic activity of the mature toxin. Additionally, a similar destabilizing effect is observed for the activated protease according to biophysical and biochemical data. Our strategy paves a novel way for the development of highly specific inhibitors of ETBF-mediated enteropathogenic conditions.

Diamond Keywords: Bacteria

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Instruments: I04-1-Macromolecular Crystallography (fixed wavelength)

Other Facilities: XALOC at ALBA

Added On: 29/09/2022 13:59

Documents:
Protein Science - 2022 - Jimenez%E2%80%90Alesanco - Repositioning small molecule drugs as allosteric inhibitors of the BFT%E2%80%903 toxin.pdf

Discipline Tags:

Pathogens Antibiotic Resistance Health & Wellbeing Biochemistry Chemistry Structural biology Biophysics Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)