Reaction of staphylococcal alpha-toxin with peptide-induced antibodies

Abstract

Two peptides representing separate 13-amino-acid sequences of staphylococcal alpha-toxin have been synthesized and acrylamide gel-purified alpha-toxin monomer and hexamer forms have been prepared and used to produce antisera in rabbits. We report here that each synthetic peptide, P-I and P-II, induces the formation of a specific precipitating antiserum. Moreover, these sera also react with the toxin monomer and sometimes with the hexamer, indicating that each peptide has more than one epitope. The purified toxin monomer can induce antibodies to fragments of toxin but is significantly less potent than the hexamer in inducing antibodies to the toxin monomer and almost not effective in inducing a response to the toxin hexamer. The purified toxin hexamer induces responses that are almost the reciprocals of the monomers, with the antihexamer and-monomer responses dominating and almost no responses to fragments of toxin being induced. These responses are interpreted in terms of the stability of the toxin hexamer to proteolytic degradation, compared with the relative sensitivity of the monomer to proteases. In assays of toxinneutralization activity, only those sera containing antihexamer antibodies can block toxin hemolytic activity. This is true for both peptideand toxin-induced antisera. The basis for this apparent association between

Staphylococcal alpha toxin: a study with chronically instrumented awake sheep

“…Also, it is probable that some alpha toxin is neutralized by binding nonproductively to nonreactive cells antibodies during the course of these experiments by the repeated administration of alpha toxin appears either to TIME (MINUTES) block the response to alpha toxin or to require the use of and PLA in sheep VS-201-89 following a lethal greatly increased doses to achieve comparable responses. 3 alpha toxin to evoke a response in the sheep is consistent with the previous in vitro finding of its lack of hemolytic activity (5,17,26) and with the demonstration of the toxoid property of the purified hexamer form of alpha toxin (3,15,16). Figure 4 summarizes the various mechanisms that we speculate contribute to a lack of response to alpha toxin.…”

“…The anti-alpha toxin antibody was polyclonal rabbit serum obtained after immunization of rabbits with alpha toxin excised from denaturing polyacrylamide electrophoresis gets (16).…”

Alpha-toxin of Staphylococcus aureus.

“…Harshman et al generated monoclonal antibodies against N-and C-terminal peptide domains (68,73). Because an antibody directed against an epitope located in the C-terminal fragment inhibited the binding of alpha-toxin to cells, the binding region was proposed to reside in the C-terminal half of the molecule.…”

Inhibition of Pore-Forming Proteins

“…In addition to the anthrax toxin, many studies have been done on finding neutralizing mAbs against other pathogenic PFPs, such as toxin B from Clostridium difficile [151], S. aureus α-toxin [152,153], Clostridium perfringens ε-toxin [154,155], and others. Interestingly, some broad-spectrum mAbs were found to inhibit disparate PFPs, for example α-toxin together with four different types of leukotoxins [156].…”