Purification of the delta toxin of Staphylococcus aureus

Abstract

An improved procedure for the purification of the delta toxin of Staphylococcus aureus strain E-delta has been devised which relies upon precipitation at pH 4.0 and further treatment with ammonium sulphate. A final step consists of passage twice through a column of DEAE-cellulose. Toxin obtained by this method appeared to be homogeneous on the basis of immunodiffusion and electrophoresis studies. However, two peaks with sedimentation coefficients of 2.8 S and 9.8 S were obtained when toxin was examined in the ultracentrifuge. Proline was identified as the N-terminal amino acid. No other N-terminal amino acids were detected in the purified toxin.