Purification and some properties of bacteriophage T4 particle-associated lysozyme.

Bacteriophage T4 particle-associated lysozyme, purified to electrophoretic homogeneity, was found to be a protein with a relative molecular mass of 15000. The lysozyme was purified from the particles of bacteriophage T4 e mutant and from the lysates of the 5tsl e T4 mutant, in which the enzyme is in soluble form. In the purification procedure advantage was taken of the affinity of the enzyme for GlcNAc-MurNac-LAla-DGlu-msA2pm-DAla (C6 muropeptide), one of the products of the digestion of Escherichia coli murein with lysozyme. The test for the quick estimation of bacteriolytic activity of the enzyme, using E. coli B freeze-dried cells, is described. The pH optimum of the particle-associated lysozyme was equal to about 6.0, ionic strength optimum to 0.05-0.1 M, and optimum Triton X-100 concentration to 1%, when this substrate was used. Some of the aspects of the possible biological significance of the particle-associated lysozyme in bacteriophage T4 infection are discussed.