March 18, 2014

By: dpinkston@listlabs.com

Shiga Toxins May be Purchased without Government Approval

The CDC has removed Shiga toxins (Stx1 and Stx2) from the list of materials requiring oversight.  As a result, Shiga Toxins are no longer classified as select agents and may be purchased without government approval for your research and investigative needs.   While Shiga toxins carry fewer restrictions, the interest in them and their value for research has never been higher.

Usage of Shiga Toxins in Research

As tools, these cytotoxins are valuable in studying intracellular transport within the Golgi apparatus.  They can be used to eliminate mammalian cell types with Gb3 receptors. Shiga toxins are potent virulence factors, important in human health.  They are implicated in many cases of food borne illness, estimated to affect 76 million people and cause 5,000 deaths every year in the United States alone.  Shiga toxin producing bacteria, usually Escherichia coli O157, enter the food chain through contamination, infect the gastrointestinal tract and cause diarrheal illness.  The bacteria infect the large intestine and produce Shiga toxin which crosses the gastrointestinal epithelium entering the blood stream; ultimately the toxins are responsible for organ damage.  These potent virulence factors are important targets for the development of therapies and for the detection of contamination.

Shiga toxins function by inhibiting eukaryotic protein synthesis by cleaving a specific adenine from the 28S RNA of the 60S subunit of the ribosome.  Although Shiga toxin 1 and Shiga toxin 2 share only 56% amino acid homology, making them immunologically distinct, activities of these two forms of toxin, binding affinity to Gb3 and N-glycosidase activity, appear to be identical.  In spite of these similarities, Shiga toxin 2 is more closely associated with human disease.  Although endothelial cells are the primary cell type vulnerable to shiga toxin, several other types express Gb3 receptors and are therefore potential targets.

Get Shiga Toxins for Research from ListLabs

Both Shiga 1 and Shiga 2 and mouse antibodies to the toxins are available from List Labs. You can read more about them here. At this time we are evaluating polyclonal and monoclonal antibodies that recognize all seven subtypes of Stx2 and monoclonals that recognize all subtypes of Stx1.  Look for these antibodies to appear in our future offerings.