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Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
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Published on: December 17, 2013

Pbp, a cell-surface exposed plasminogen binding protein of Bacteroides fragilis

Robert Sijbrandi1, Michiel Stork, Joen Luirink

  • 1Department of Molecular Microbiology, Faculty of Earth and Life Sciences, VU-University Amsterdam de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.

Microbes and Infection
|April 12, 2008
PubMed

Insights

Bacteroides fragilis plasminogen binding protein (Pbp) is a cell surface protein crucial for plasminogen binding. This protein is implicated as a virulence factor in intra-abdominal infections caused by B. fragilis.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Molecular Biology

Background:

  • Bacteroides fragilis, a Gram-negative anaerobic bacterium, resides in the human gut but is linked to severe intra-abdominal infections.
  • Virulence factors of B. fragilis are key to its role in infection development.

Purpose of the Study:

  • To identify and characterize a putative plasminogen binding protein (Pbp) from B. fragilis.
  • To investigate the role of Pbp in plasminogen binding and its potential contribution to pathogenicity.

Main Methods:

  • Gene cloning, sequencing, and protein expression in E. coli.
  • Subcellular localization studies using protease accessibility assays.
  • Assessment of Pbp's necessity and sufficiency for plasminogen binding.

Main Results:

  • A ~60-kDa protein, Pbp, was identified and localized to the outer membrane and cell surface of B. fragilis.
  • Pbp was sufficient and necessary for plasminogen binding to whole bacterial cells.
  • Pbp-like proteins were found in other Bacteroides subspecies.

Conclusions:

  • The cell surface protein Pbp plays a significant role in B. fragilis-mediated plasminogen binding.
  • Pbp is a potential virulence factor contributing to the pathogenicity of B. fragilis infections.

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