The purification and properties of two staphylolytic enzymes from Streptomyces griseus.

1. Two staphylolytic enzymes have been purified from cultures of a soil isolate of Streptomyces griseus. 2. The purified enzymes were shown to be basic proteins of low molecular weight. Each enzyme released N-acetylmuramic acid reducing groups from the cell walls of Staphylococcus aureus. 3. The enzymes lysed whole staphylococci best at higher pH values and lower ionic strengths than when the substrate was isolated cell walls or purified mucopeptide. 4. Added teichoic acid did not inhibit the enzymes, but it formed an ethanol-precipitable complex with them. 5. The possibility that teichoic acid on the surface of whole cells prevents the access of the enzymes to their mucopeptide substrate is discussed.