Pyocin S2, a bacteriocin, was purified from the mitomycin C-induced lysate of Pseudomonas aeruginosa strain M47. The preparation was chromatographically homogeneous and sodium dodesyl sulfate (SDS) disc gel electrophoresis showed a single staining band. The conditions to keep its activity stable were defined. Pyocin S2 appears to be a simple protein: it contains neither detectable amount of carbohydrate nor phosphorus. Its amino acid composition was analyzed. Its molecular weight was determined to be approximately 72, 000 from its mobility on SDS disc gel electrophoresis or 78, 000 from its sedimentation coefficient of 4.2 S combined with the elution profile of Sephadex G-200 chromatography. The frictional ratio was calculated to be 1.52.
The killing action of pyocin S2 on the sensitive cells showed a single hit process.