title: The identification and purification of multiple forms of theta-haemolysin (theta-toxin) of Clostridium perfringens type A.
abstract: The theta-haemolysin of Clostridium perfringens was purified from culture supernatant fluids of type A strains by fractional ammonium sulphate precipitation and isoelectric focusing in narrow pH 5 to 8 gradients. Four components detected on electrofocusing were designated theta-1(pI6-8to6-9),theta-2(pI6-5to6-6),theta-3(pI6-1to6-3) and theta-4(pI5-7to5-9). Specific activities ranged from 0-4 x 10-6 to 1-2 x 10-6 haemolytic units/mg protein and 2950 to 3600 LD-50/mg protein. Each haemolytic component was activated by cysteine hydrochloride, and inactivated by cholesterol, by addition of sheep erythrocyte ghosts and by heating at 60 degrees C for 10 min; mouse erythrocytes were more resistant than sheep erythrocytes to haemolysis. A reaction of identity was obtained between components in gel diffusion. Sodium dodecyl sulphate polyacrylamide discgel electrophoresis gave molecular weights in the range 59,000 to 62,000 for each component. A similar value was obtained for theta-1 on density gradient ultracentrifugation. Although the multiple forms were free of 11 factors present  in culture supernatants, crossed immunoelectrophoresis and disc gel electrophoresis revealed minor contaminants. These studies reveal that theta-haemolysin has physical properties in common with other oxygen-labile haemolysins.
mesh_terms: D000645:Ammonium Sulfate; D000818:Animals; D002499:Centrifugation, Density Gradient; D005591:Chemical Fractionation; D002784:Cholesterol / Q000494:pharmacology; D003016:Clostridium perfringens / Q000032:analysis*; D003545:Cysteine / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000276:immunology; D006460:Hemolysin Proteins / Q000032:analysis / Q000302:isolation & purification; D006461:Hemolysis; D006358:Hot Temperature; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007525:Isoelectric Focusing; D007928:Lethal Dose 50; D051379:Mice / Q000276:immunology; D008970:Molecular Weight; D012756:Sheep / Q000276:immunology
chemical_list: D006460:Hemolysin Proteins; D002784:Cholesterol; D003545:Cysteine; D000645:Ammonium Sulfate