title: Purification and characterisation of two forms of toxin B produced by Clostridium difficile.
abstract: Toxin B from Clostridium difficile was purified to homogeneity by gel filtration and high resolution ion exchange chromatography. Two forms of toxin B were found. Form 1 which seemed to consist of two identical subunits of 220-300 kDa; femtogram amounts of this toxin induced rounding of fibroblast cells. Form 2 contained subunits of 43 kDa and 105 kDa; the stoichiometric ratio probably being 4:1; picogram amounts were needed to induce rounding of fibroblast cells. Immunological studies suggested that both subunit types were antigenic and had epitopes which were identical with those of form 1.
mesh_terms: D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000302:isolation & purification* / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003013:Clostridium / Q000032:analysis*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006801:Humans; D005779:Immunodiffusion; D008168:Lung / Q000166:cytology / Q000187:drug effects; D008970:Molecular Weight
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; C031815:toxB protein, Clostridium difficile