The lytic enzyme of the Pseudomonas phage phi 6. Purification and biochemical characterization

Biochim Biophys Acta. 1992 Sep 4;1159(1):44-50. doi: 10.1016/0167-4838(92)90073-m.


The lytic enzyme of the lipid-containing bacteriophage phi 6, protein P5, has been purified to apparent homogeneity from disrupted viral particles. The enzyme is a monomer with a molecular mass of approx. 24 kDa. The optimal pH for P5 activity is 8.5 and the protein is readily inactivated at temperatures above 20 degrees C. Protein P5 is active against several Gram-negative bacteria, but no activity against Gram-positive species was detected. Analysis of cell wall digests indicates that P5 is not a glycosidase, but an endopeptidase splitting the peptide bridge formed by meso-diaminopimelic acid and D-alanine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophage phi 6 / enzymology*
  • Endopeptidases / isolation & purification*
  • Endopeptidases / metabolism
  • Gram-Negative Bacteria / metabolism
  • Gram-Positive Bacteria / metabolism
  • Hydrogen-Ion Concentration
  • Nephelometry and Turbidimetry
  • Substrate Specificity
  • Temperature
  • Viral Proteins / isolation & purification
  • Viral Proteins / metabolism


  • Viral Proteins
  • Endopeptidases
  • protein P5, Pseudomonas phage phi 6