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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
14:05

Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes

Published on: September 19, 2013

Characteristics of the biologically active 35-kDa metalloprotease virulence factor from Listeria monocytogenes

A Coffey1, B van den Burg, R Veltman

  • 1Laboratory of Food Microbiology, Wageningen Agricultural University, The Netherlands.

Journal of Applied Microbiology
|March 29, 2000
PubMed

Insights

Listeria monocytogenes produces an extracellular protease essential for virulence. This study identifies optimal conditions for its production and characterizes its properties, revealing it as a heat-stable metalloprotease.

Area of Science:

  • Microbiology
  • Biochemistry
  • Structural Biology

Background:

  • Listeria monocytogenes is a pathogen that spreads via cell-to-cell transmission.
  • Extracellular protease production is crucial for Listeria monocytogenes virulence, specifically for lecithinase maturation.
  • Understanding protease production and characteristics is key to developing control strategies.

Purpose of the Study:

  • To determine environmental factors promoting the production of active Listeria monocytogenes protease.
  • To isolate and biochemically characterize the mature protease.
  • To elucidate the structural basis for the protease's stability and specificity.

Main Methods:

  • Optimizing environmental parameters for protease production.
  • Developing polyclonal antibodies for protease detection.
  • Utilizing high-performance liquid affinity chromatography for isolation.
  • Biochemical assays using casein and actin as substrates.
  • Homology modeling for structural analysis.

Main Results:

  • Identified environmental conditions for increased production of the 35-kDa active protease.
  • Isolated the active protease and characterized it as a zinc-dependent metalloprotease.
  • Demonstrated protease activity against casein across broad pH and temperature ranges.
  • Showed the protease degrades actin and possesses high thermal stability with narrow substrate specificity.
  • Developed a 3D model based on thermolysin homology.

Conclusions:

  • Established optimal conditions for producing a key virulence factor of Listeria monocytogenes.
  • Characterized the protease as a stable metalloprotease with implications for virulence.
  • Structural insights provide a basis for understanding the protease's functional characteristics.

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