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Mur-LH, the broad-spectrum endolysin of Lactobacillus helveticus temperate bacteriophage phi-0303

Stéphanie-Marie Deutsch1, Stéphane Guezenec, Michel Piot

  • 1Laboratoire de Recherches de Technologie Laitière, Institut National de la Recherche Agronomique, 35042 Rennes Cédex, France. sdeutsch@labtechno.roazhom.inra.fi

Applied and Environmental Microbiology
|January 9, 2004
PubMed

Insights

Researchers cloned and characterized the phi-0303 bacteriophage lysin gene from Lactobacillus helveticus. The resulting endolysin, Mur-LH, demonstrated broad-spectrum N-acetylmuramidase activity against various bacterial species.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Bacteriophages are viruses that infect bacteria.
  • Temperate bacteriophages can integrate their genome into the host or remain as a plasmid.
  • Bacteriophage-derived lysins are enzymes with potential antimicrobial applications.

Purpose of the Study:

  • To clone and characterize the gene encoding a lytic protein from the Lactobacillus helveticus bacteriophage phi-0303.
  • To investigate the enzymatic activity and substrate specificity of the expressed lysin.
  • To assess the potential of the lysin as a broad-spectrum antimicrobial agent.

Main Methods:

  • Cloning of the phi-0303 lysin gene in Escherichia coli.
  • Expression and purification of the recombinant lysin (Mur-LH).
  • Enzymatic assays using whole bacterial cells and cell wall hydrolysis.
  • Biochemical analysis and N-terminal sequencing of the protein.

Main Results:

  • The lysin gene (lys) was identified within a 4.1-kb DNA fragment of phi-0303.
  • The lys gene encodes a 373-amino acid protein (Mur-LH) with a molecular mass of 40,207 Da.
  • Recombinant Mur-LH exhibited N-acetylmuramidase activity against Lactobacillus helveticus cell walls.
  • The endolysin showed broad-spectrum lytic activity against various Gram-positive bacteria, including lactobacilli, lactococci, and Bacillus subtilis.

Conclusions:

  • The phi-0303 bacteriophage encodes an endolysin, Mur-LH, with potent N-acetylmuramidase activity.
  • Mur-LH displays a broad spectrum of lytic activity, making it a promising candidate for antimicrobial applications.
  • This study contributes to understanding bacteriophage lysins and their potential use in combating bacterial infections.

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