title: Cytotoxin from an ovine strain of Pasteurella haemolytica: characterisation studies and partial purification.
abstract: A cell-free, water-soluble cytotoxin from an ovine strain of Pasteurella haemolytica biotype A serotype 1 killed sheep bronchoalveolar macrophages at 37 degrees C, but not at 4 degrees C or 22 degrees C. The cytotoxin was stable over the pH range 2-12, resistant to heat at 60 degrees C but inactivated at 100 degrees C or by autoclaving. Trypsin also destroyed the cytotoxin, which is therefore thought to contain a protein component essential for biological activity. A preliminary purification of the crude cytotoxin using gel-filtration column chromatography resulted in the isolation of a biologically active fraction which resolved as a single protein band and one carbohydrate band on non-dissociating polyacrylamide gels. However, this fraction resolved into approximately 16 component bands on a sodium dodecyl sulphate polyacrylamide gel.
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification; D001427:Bacterial Toxins / Q000302:isolation & purification*; D003603:Cytotoxins / Q000302:isolation & purification*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008264:Macrophages / Q000187:drug effects; D008970:Molecular Weight; D010325:Pasteurella / Q000032:analysis*; D012756:Sheep; D012995:Solubility; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins