Purification and characterization of a staphylococcal epidermolytic toxin

Abstract

A staphylococcal exotoxin that causes epidermolysis when injected into the skin of the newborn mouse and man was highly purified by coventional biochemical techniques. With Staphylococcus aureus EV, the epidermolytic toxin was a major protein component of supernatant culture fluids. The initial step in purification was zone electrophoresis in Pevikon carried out at pH 9.0, the isoelectric point of alpha-hemolytic toxin, which remained near the origin. Fractions containing the epidermolytic toxin, but free of alpha-toxin, were then subjected to cation exchange chromatography on carboxymethyl-Sephadex C-50 to remove trace contaminants. A major highly purified epidermolytic toxin migrated as a single band in polyacrylamide gel electrophoresis, sedimented as a single component in the analytical ultracentrifuge, and elicited a single precipitating antibody after injection into rabbits. A smaller amount of a second epidermolytic toxin, identical in molecular weight and antigenicity but differing in electrophoretic behavior from the major molecular species, was also identified. The epidermolytic factor had a molecular weight of 28,600 +/- 400 by sodium dodecyl sulfate-acrylamide electrophoresis and 32,500 +/- 120 by approach to sedimentation equilibrium.