Separation of two hemolysins from Aeromonas hydrophila by isoelectric focusing

Two hemolytic proteins (hemolysin I and II) with isoelectric points of 5.5 and 4.3 were purified by isoelectric focusing from the culture supernatant fluid of Aeromonas hydrophila. The purified hemolysins were unstable after dialysis and upon heating at 37 C and were inactivated by proteolytic enzymes. The two hemolysins were lethal for mice in a dose of 10 mug (hemolysin I) and 3 mug (hemolysin II) and showed similar hemolytic spectra on red cells of different species. Both were also cytotoxic for HeLa cells and human fibroblasts and gave dermonecrosis in rabbits.