Shiga Toxins

Shiga toxins, also called verotoxins, consists of two domains: the A polypeptide confers the activity, and the B polypeptide pentamer confers the receptor-specific binding. The A polypeptide has an N-glycosidase activity that cleaves an adenine from the 28S rRNA of the 60S cytoplasmic ribosome. This activity renders the 28S rRNA unable to interact with the elongation factors EF-1 and EF-2, thus inhibiting protein synthesis. The B polypeptide forms a pentamer that binds to the eukaryotic cell receptor globotriaosylceramide (Gb3). Shiga toxins then enter the cells by receptor-mediated endocytosis.

Once the Shiga toxins have been endocytosed, they are retrogradely transported through the Golgi apparatus to the rough endoplasmic reticulum where they effectively target the ribosomes. In addition to inhibiting protein synthesis, Shiga toxins induce cytokines such as interleukin-1, interleukin-6, and interleukin-8. They have also been shown to induce expression of tumor necrosis factor (TNF), induce F-actin depolymerization, and activate a Src kinase.

The effects of Shiga toxin 1 and Shiga toxin 2 have been shown to vary with cell type because Gb3 receptors are present in certain tissues, particularly sensory neurons and renal cells. In those cell types, the receptor concentration and binding is modulated by factors such as tumor necrosis factor (TNF), interleukins, and fatty acid content of the membranes. Shiga toxin 1 and Shiga toxin 2 differ in their effects on various tissues. However, they have both been shown to induce apoptosis in several different cell types.

Shiga toxin 1 and 2 provided by List Labs are recombinantly expressed in E. coli and are highly purified. Shiga toxins are very toxic and should be handled with extreme caution.

• Product #161 Shiga Toxin 1, recombinant from E. coli, is provided lyophilized in PBS buffer.
• Product #162 Shiga Toxin 2, recombinant from E. coli, is provided as a liquid in a Tris buffer solution.

Shiga Toxin Antibodies

Rabbit polyclonal antibodies to Shiga Toxin 1 and 2 are provided by List. Anti-Shiga Toxin Camelid Antibody, which is a heterotetramer VHH that recognizes both Shiga Toxin 1 and Shiga Toxin 2, is also available. Anti-Shiga Toxin 1 or Anti-Shiga Toxin 2 Antibody, when paired with the Anti-Shiga Toxin Camelid Antibody, can be used in a standard sandwich ELISA.

• Product #761 Anti-Shiga Toxin 1 (Rabbit), IgG is provided as a frozen liquid in PBS buffer solution.
• Product #765 Anti-Shiga Toxin 2 (Rabbit), IgG is provided as a frozen liquid in PBS buffer solution.
• Product #766 Anti-Shiga Toxin Camelid Antibody, VHH is provided as a liquid in PBS buffer solution.