A protease with staphylolytic activity from Pseudomonas aeruginosa PAKS I

The supernatant from broth cultures of Pseudomonas aeruginosa PAKS I contains two different enzymes with staphylolytic activity. One of them, namely staphylolytic enzyme, seems to be specific for glycine-rich cross-links present in the cell wall of different Gram-positive bacteria and has been previously characterized. In addition to the staphylolytic activity, the second protein which we propose to be a staphylolytic protease, has proteolytic activity against casein. This enzyme is approximately 33 kDa, has an isoelectric point ranging from 7.3 to 8.1 and an optimum pH value of 8.0 for casein hydrolysis. Staphylolytic protease was detected in the extracellular medium after 12 h of cell growth. Immunocytochemical studies suggest that the protease is located within the periplasmic space of P. aeruginosa.