Specificity of a bacteriolytic enzyme from Pseudomonas aeruginosa.

A bacteriolytic enzyme isolated from shake-flask cultures of Pseudomonas aeruginosa and capable of lysing cells of Staphylococcus aureus was purified approximately 500-fold by passage through diethylaminoethyl cellulose and chromatography on carboxymethyl-cellulose. The purified enzyme was shown to act as an endopeptidase, cleaving the pentaglycine cross-bridges of the cell wall peptidoglycan at d-alanyl-glycine and glycyl-glycine linkages with the release of di-, tri-, and tetraglycine fragments. Release of NH(2)-alanine indicated weak N-acetylmuramyl-l-alanine amidase activity, but most of the residual peptide remained attached to the glycan. No hydrolysis of the glycan occurred. The lytic spectrum of the enzyme toward a variety of other cell walls of known peptidoglycan composition indicated relatively high specificity for peptidoglycans with polyglycine bridges.