Purification and characterization of a vulnificolysin-like cytolysin produced by Vibrio tubiashii

An extracellular cytolysin from Vibrio tubiashii was purified by sequential hydrophobic interaction chromatography with phenyl-Sepharose CL-4B and gel filtration with Sephacryl S-200. This protein is sensitive to heat and proteases, is inhibited by cholesterol, and has a molecular weight of 59,000 and an isoelectric point of 5.3. In addition to lysing various erythrocytes, it is cytolytic and/or cytotoxic to Chinese hamster ovary cells, Caco-2 cells, and Atlantic menhaden liver cells in tissue culture. Lysis of erythrocytes occurs by a multihit process that is dependent on temperature and pH. Twelve of the first 17 N-terminal amino acid residues (Asp-Asp-Tyr-Val-Pro-Val-Val-Glu-Lys-Val-Tyr-Tyr-Ile-Thr-Ser-Ser-Lys) are identical to those of the Vibrio vulnificus cytolysin.