Beta-toxin was purified about 340-fold from culture supernatant fluid of Clostridium perfringens type C with a yield of about 24% in terms of biologically active beta-toxin. The purification involved ammonium sulfate fractionation, gel filtration through Sephadex G-100, isoelectrofocusing in a pH 3 to 6 gradient, and immunoaffinity chromatography. The purified beta-toxin gave a single band on p...

Beta toxin is a neutral sphingomyelinase secreted by certain strains of Staphylococcus aureus. This virulence factor lyses erythrocytes in order to evade the host immune system as well as scavenge nutrients. The structure of beta toxin was determined at 2.4-A resolution using crystals that were merohedrally twinned. This structure is similar to that of the sphingomyelinases of Listeria ivanovii...

Achieving efficient heterologous protein production and secretion by Bacillus subtilis is an attractive prospect, although often disappointingly low yields are reached. The expression of detoxified Clostridium perfringens beta-toxin (beta-toxoid) is exemplary for this. Although beta-toxin can be efficiently expressed and secreted by Bacillus subtilis, the genetically detoxified, and industriall...

Beta-toxin is one of the lethal toxins of Clostridium perfringens. It shares sequence homology with the pore-forming alpha-toxin of Staphylococcus aureus and structural homology has been indicated by mutagenesis studies. Human endothelial cells are sensitive to the toxic effect of alpha-toxin and in order to investigate the function of beta-toxin we have looked at the effect of the protein on h...

The interaction of two Bacillus thuringiensis cytolytic toxins, CytA and CytB, with a phospholipid bilayer and their structure in the membrane-bound state were investigated by proteolysis using phospholipid vesicles as a model system. A toxin conformational change upon membrane binding was detected by comparing the proteolytic profile of membrane-bound toxin and saline-solubilized toxin. When m...

In this research a molecular method based on polymerase chain reaction for typing of Clostridium perfringens was developed and toxin genotypes of 64 isolates from sheep and goats in Iran were determined. The PCR assays were developed for detection of alpha (cpa), beta (cpb) and epsilon (etx) toxin genes, allowing classification of the isolates into genotypes A B, C and D. The field isolates ...

in this research a molecular method based on polymerase chain reaction for typing of clostridium perfringens was developed and toxin genotypes of 64 isolates from sheep and goats in iran were determined. the pcr assays were developed for detection of alpha (cpa), beta (cpb) and epsilon (etx) toxin genes, allowing classification of the isolates into genotypes a b, c and d. the field isolates ...

The intermediate lobe cells of pituitary gland synthesize and secrete bioactive peptides derived from proopiomelanocortin. In the present study, we investigated the effects of cholera toxin on the release of beta-endorphin (beta-Ep) from dispersed-intermediate lobe cells of rats. Cholera toxin added into culture medium, enhanced the intracellular accumulation of adenosine 3', 5'-monophosphate (...

Clostridium perfringens beta-toxin is a key mediator of necrotizing enterocolitis and enterotoxemia. It is a pore-forming toxin (PFT) that exerts cytotoxic effect. Experimental investigation using piglet and rabbit intestinal loop models and a mouse infection model apparently showed that beta-toxin is the important pathogenic factor of the organisms. The toxin caused the swelling and disruption...

BACKGROUND Presentation after Clostridium difficile infection may depend on the level of epithelial exposure to toxins. We investigated epithelial barrier function and expression of interleukin (IL)-8 and transforming growth factor (TGF)-beta in response to varying concentrations of C. difficile toxin A. METHODS T84 cells were either preexposed or continuously exposed to C. difficile toxin A ...