Shiga toxin is a bacterial toxin consisting of A and B subunits. Generally, the essential cytotoxicity of the toxin is thought to be mediated by the A subunit, which possesses RNA cleavage activity and thus induces protein synthesis inhibition. We previously reported, however, that the binding of the Shiga toxin 1-B subunit to globotriaosyl ceramide, a functional receptor for Shiga toxin, induc...

BACKGROUND Shiga toxin-producing E. coli (STEC) are a group of common and potentially deadly intestinal pathogens expressing Shiga toxin (Stx) as a primary virulence factor. Of the two types of Stx, Stx2 is responsible for more severe symptoms during infection, while Stx1 is almost identical to the Shiga toxin from Shigella dysenteriae, a ubiquitous pathogen in developing countries. Although an...

The Dsb family of enzymes catalyzes disulfide bond formation in the gram-negative periplasm, which is required for folding and assembly of many secreted proteins. Pertussis toxin is arguably the most complex toxin known: it is assembled from six subunits encoded by five genes (for subunits S1 to S5), with 11 intramolecular disulfide bonds. To examine the role of the Dsb enzymes in assembly and ...

UNLABELLED Epsilon toxin secreted by Clostridium perfringens types B and D has been directly implicated as the causative agent of fatal enterotoxemia in domestic animals. The aim of the present study is to use in silico approach for identification of B-cell epitope(s) of epsilon toxin, and its expression in fusion with a carrier protein to analyze its potential as vaccine candidate(s). Using di...

The genes that encode the enterotoxigenic Escherichia coli (ETEC) CS4 fimbriae, csaA, -B, -C, -E, and -D', were isolated from strain E11881A. The csa operon encodes a 17-kDa major fimbrial subunit (CsaB), a 40-kDa tip-associated protein (CsaE), a 27-kDa chaperone-like protein (CsaA), a 97-kDa usher-like protein (CsaC), and a deleted regulatory protein (CsaD'). The predicted amino acid sequences...

This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure-activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) ...

References 1. Schmidt H. Shiga-toxin-converting bacteriophages. Res Microbiol. 2001;152:687–95. http://dx.doi.org/10.1016/ S0923-2508(01)01249-9 2. Melton-Celsa A, Mohawk K, Teel L, O’Brien A. Pathogenesis of Shiga-toxin producing Escherichia coli. Curr Top Microbiol Immunol. 2012;357:67–103. http://dx.doi.org/10.1007/82_2011_176 3. Manning SD, Motiwala AS, Springman AC, Qi W, Lacher DW, Ouelle...

As is the case for Saccharomyces boulardii, Saccharomyces cerevisiae W303 protects Fisher rats against cholera toxin (CT). The addition of glucose or dinitrophenol to cells of S. boulardii grown on a nonfermentable carbon source activated trehalase in a manner similar to that observed for S.cerevisiae. The addition of CT to the same cells also resulted in trehalase activation. Experiments perfo...

The present study uses the B subunit of cholera toxin, a protein that binds specifically to ganglioside GM1, to examine the role of endogenous GM1 in the process of growth and differentiation of mouse neuroblastoma N18 cells. Binding of the B subunit to neuroblastoma N18 cells inhibited DNA synthesis with concomitant induction of differentiation. The B subunit induced pronounced morphological c...