STUDIES WITH STAPHYLOCOCCAL TOXINS: V. POSSIBLE IDENTIFICATION OF ALPHA HEMOLYSIN WITH A PROTEOLYTIC ENZYME

Abstract

Alpha hemolysin has been separated from many of the other components present in culture filtrates of four strains of Staphylococcus aureus using a column chromatographic procedure with carboxymethyl-cellulose as the selective adsorbent, and graded levels of phosphate buffer at pH 6.0 to provide selective elution. The preparation of alpha hemolysin obtained in this manner hemolyzed rabbit and sheep erythrocytes, induced a dermonecrotic reaction in rabbits, was lethal to mice, and was proteolytic. The hemolytic activity of the preparation was stimulated by ethylenediamine tetraacetic acid, presumably by removing toxic ions from solution. Divalent cations inhibited activity of the alpha hemolysin, but stimulated the activity of a distinctive sheep hemolysin, which is shown to be a separate entity.Alpha hemolysin, obtained by the chromatographic procedure, and subjected further to resolution by zone electrophoresis retained its capacity to induce dermonecrosis, to hemolyze rabbit erythrocytes, and to hydrolyze casein. Apparent loss of the capacity of the preparation to hemolyze sheep erythrocytes was discussed.The possibility that alpha hemolysin is a specific proteolytic enzyme is suggested by the observation that under no conditions could a separation be effected between the hemolytic and proteolytic properties of the alpha hemolysin recovered from a number of different cultures.