[Purification and some properties of bacteriolytic enzyme R1 from Streptomyces griseus RX-17]

Bacteriolytic enzyme R1 was purified to electrophoretic homogeneity with the recovery of 6.89% activity by ammonium sulfate precipitation, CM-Sephadex C - 50, CM-Sepharose Fast Flow and Sephadex G-75 chromatography from the culture supernatant of Streptomyces griseus RX-17. The molecular weight and PI of R1 were 16.8 kD and 9.10. The optimal temperature and pH for R1 against Streptococcus mutans Ingbritt were 70 degrees C and 6.6, respectively. Below 50 degrees C and at range pH 6 - 10, R1 was stable. While treated at 60 degrees C for 1 hour, the residual activity was only about 20.3%. Zn2+, Cu2+, Fe2+, Cd2+ and Pb2+ could completely inactivate the enzyme. Chelating agents, hydroxylamine hydrochloriae, Monoiodoacetic acid inhibited the lytic activity against Streptococcus mutans Ingbritt, whereas Mg2+, 2-Mercaptoethanol and some surfactants could stimulate the activity. The enzyme had a broad bacteriolytic spectrum against many G+, G- bacteria which were resistant to egg-white lysozyme. Especially high activity was shown on Streptococcus mutans, Staphylococcus aureus and Lactobaillus.