The Properties of Phospholipase Enzymes in Staphylococcal Toxins

Abstract

SUMMARY Two phospholipase enzymes have been identified in toxic preparations from Staphylococcus aureus, each having a mode of action like that of phospholipase C. One enzyme hydrolysed phosphatidyl inositol and lysophosphatidyl inositol, while the other hydrolysed sphingomyelin and lysophosphatidyl choline. The latter enzyme was always associated with β-haemolysin activity and it is concluded that β-haemolysin, sphingomyelinase and lysophospholipase are activities of one protein. A phospholipase A was also detected in a toxic preparation from an αβ strain. A study of cultural conditions showed that this enzyme was produced under a variety of conditions, but only when the β-haemolysin activity was high.