Shiga toxin (Stx) is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC) infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs) are short linear aminoacidic sequences, with a positive net charge, which di...

Accelerating rates of health care-associated infections caused by Clostridium difficile, with increasing recurrence and rising antibiotic resistance rates, have become a serious problem in recent years. This study was conducted to explore whether a combination of antibiotics with human antimicrobial peptides may lead to an increase in antibacterial activity. The in vitro activities of the antim...

Recent studies have shown that only a subset of major histocompatibility complex (MHC) class II molecules are able to present bacterial superantigens to T cells, leading to the suggestion that class-II associated peptides may influence superantigen presentation. Here, we have assessed the potential role of peptides on superantigen presentation by (a) analyzing the ability of superantigens to bl...

The primary structure of Cerebratulus lacteus toxin B-II has been investigated by automated Edman degradation of the reduced, carboxymethylated protein and of tryptic peptides derived from the maleylated protein. As a result of these studies, the identity of all 55 amino acid residues in the polypeptide chain has been unambiguously determined. Hydroxyproline, an amino acid not normally found in...

Toxin-antitoxin (TA) systems play important roles in bacterial physiology, such as multidrug tolerance, biofilm formation, and arrest of cellular growth under stress conditions. To develop novel antimicrobial agents against tuberculosis, we focused on VapBC systems, which encompass more than half of TA systems in Mycobacterium tuberculosis. Here, we report that theMycobacterium tuberculosis Vap...

Exocytosis of secretory granules by adrenal chromaffin cells is blocked by the tetanus toxin light chain in a zinc specific manner. Here we show that cellular synaptobrevin is almost completely degraded by the tetanus toxin light chain within 15 min. We used highly purified adrenal secretory granules to show that synaptobrevin, which can be cleaved by the tetanus toxin light chain, is localized...

Erabutoxin a was partially hydrolysed with enzymes and sulphuric acid and the resulting peptides were separated from each other by column chromatography and paper electrophoresis. From the results of amino acid analyses of the sulphur-containing peptides and their oxidized components, all four disulphide bridges in the toxin molecule were located. The disulphide bonds were found between half-cy...

Pore formation in the target cell membranes is a common mechanism used by many toxins in order to kill cells. Among various described mechanisms, a toroidal pore concept was described recently in the course of action of small antimicrobial peptides. Here we provide evidence that such mechanism may be used also by larger toxins. Membrane-destabilizing effects of equinatoxin II, a sea anemone cyt...

Two structurally related (48.6% amino acid sequence identity) peptides with cytotoxic activity against human non-small cell lung adenocarcinoma A549 cells were purified from the venom of the Eastern green mamba Dendroaspis angusticeps using reversed phase HPLC. The peptides were identified as members of the three-finger superfamily of snake toxins by mass fingerprinting of tryptic digests. The ...

Produced from the pathogenicity islands of Staphylococcus aureus clinical isolates, stable SprG1 RNA encodes two peptides from a single internal reading frame. These two peptides accumulate at the membrane, and inducing their expression triggers S. aureus death. Replacement of the two initiation codons by termination signals reverses this toxicity. During growth, cis-antisense RNA SprF1 is expr...