Heat stable enterotoxin

To ensure the safety of food products, representative samples must be inspected so that foodborne bacteria can be identified.15,18,19 Bacteria producing heat-stable enterotoxins, such as Staphylococcus aureus, may be identified by biochemical and serological techniques.20,21 Molecular methods are now widely used for the identification of many pathogenic foodborne bacteria,15,22,23 In addition bacteria used as starter cultures for cheese, yogurt, other fermented foods and beverages, and probiotic dietary supplements may be identified for quality assurance.22,24,25... 

Savarino SJ, Fasano A, Watson J, Martin BM, Levine MM, Guandalini S, Guerry P Enteroaggregative Escherichia coli heat-stable enterotoxin 1 represents another subfamily of E. coli heat-stable toxin. Proc Natl Acad Sci USA 1993 90 3093-3097. 

Crane, J. K., Azar, S. S., Stam, A., and Newburg, D. S. (1994). Oligosaccharides from human milk block binding and activity of the Escherichia coli heat-stable enterotoxin (STa) in T84 intestinal cells. /. Nutr. 124, 2358-2364. 

Yersinia enterocolitica Proliferation in gut associated lymphoid tissue (facultative intracellular pathogen)(heat stable enterotoxin, LPS, invasin, attachment/invasion protein adhesion Ail) Bacillus cereus Emetic toxin (vomiting) Enterotoxins (diarrheal illness) ... 

The protein that we study here is the toxic domain of heat stable Enterotoxin (PDB ID lETN). Heat stable Enterotoxins (ST) are produced by E. Coli bacteria in the intestine and are responsible for acute diarrhea in humans and animals. They display a remarkable ability... 

E. coli heat-stable enterotoxin post-SPPS modification, Bz(4-Bz)-OSu [156]... 

The targeting of antibodies to the periplasm requires the use of signal peptides. The pelB leader of the pectate lyase gene of Erwinia carotovora (56) is commonly used. The gill leader (9), the phoA leader of the E. coli alkaline phosphatase, and the ompA leader of E. coli outer membrane protein OmpA have also been used, being common to many protein expression vectors (57,58). Further examples are the heat-stable enterotoxin II (stll) signal sequence (47) and the bacterial chloramphenicol acetyltransferase (cat) leader (59). 

Field M., Graf L. H., Laird W. J. and Smith P. L. (1978) Heat-stable enterotoxin of Escherichia coli in vitro effects on guanylate cyclase activity, cyclic GMP concentration, and ion transport in small intestine. Proc. Natl. Acad. Sci. USA 75, 2800-2804. 

Gianella R. A. and Drake K. W. (1979) Effect of purified E. coli heat-stable enterotoxin on intestinal cyclic nucleotide metabolism and fluid secretion. Infect. Immun. 24, 19-23. 

Wiygul G., and Sikorowski P. P. (1991). The effect of a heat-stable enterotoxin isolated from Escherichia coli on pheromone production in fat bodies isolated from male boll weevils. Exp. exp. appl. 60, 305-308. 

A further type of PM-located GC is gastrointestinal (GI) C-type GC that is activated by the paracrine peptide hormone guanylin. Guanylin is secreted by GI cells and resultant GC activation and cGMP elevation results in increased Cl transport via the cystic fibrosis transmembrane conductance regulator (CFTR) into the intestinal lumen with resultant increased water flow. The Escherkhia coli heat-stable enterotoxin mimics guanylin in activating this intestinal C-type GC and consequently causes diarrhoea. 

B. cereus can cause two distinct types of food-bome intoxicants (as opposed to infections) (1) an emetic (vomiting) illness with a short incubation time of a few hours and (2) a diarrheal illness with an incubation time of 8-6 h. The emetic form is caused by a preformed heat-stable enterotoxin of molecular weight less than 5000 Da. The long incubation form of the illness is mediated by a heat-labile enterotoxin of molecular weight of 50 000 Da, which activates intestinal enzymes and causes intestinal fluid secretion. 

Sato, T., Gariepy, J., Lane, A., Frayman, F., Wilbur, D., Robien, W., Schoolnik, G. K., and Jardetzky, O. Structural characteristics for biological activity of heat-stable enterotoxin ST I, Biochemistry, 25, 7854,1986. 

The binding of enterotoxin (produced by several bacterial species) to another type of guanylate cyclase found in the plasma membrane of intestinal cells causes diarrhea. For example, one form of traveler s diarrhea is caused by a strain of E. coli that produces heat stable enterotoxin. The binding of this toxin to an enterocyte plasma membrane receptor linked to guanylate cyclase triggers excessive secretion of electrolytes and water into the lumen of the small intestine. 

Leitman, D. C., Waldman, S. A., and Murad, F. (1994). Regulation of particulate guanylate cyclase by natriuretic peptides and Escherichia coli heat-stable enterotoxin. Adv. Pharmacol. 26, 67-86. 

Forte, L. R., Thorne, P. K., Eber, S. L., et al. (1992). Stimulation of intestinal CL transport by heat-stable enterotoxin Activation of cAMP-dependent protein kinase by cGMP. Am. J. Physiol. 263, C607-C615. 

Regulation of Articulate Guanylate Cyclase by Natriuretic Peptides and Escherichia coli Heat-Stable Enterotoxin Dale C. Leitman, Scott A. Waldman, and Ferid Murad... 

Some receptors appear to be linked to the stimulation of guanylyl-cyclase. These membrane receptors mediate the action of the atrial natriuretic peptide (ANP), the heat-stable enterotoxin of E. coli and the receptors involved in fertilization in some species. These membrane receptors are glycoproteins of about 130-160 kDa spanning the membrane only once. The binding of the peptides occurs at the extracellular domain, while the intracellular regions contain both cyclase catalytic domains, converting GTP to cGMP, and a protein kinase-like domain. 

Bassford P J, Silhavy T J, Beckwith J R (1979). Use of gene fusion to study secretion of maltose-binding protein into Escherichia coli periplasm. J. Bact. 139 19-31. Yamanaka H, Nomura T, Fuji Y, Okamoto K (1998). Need for TolC, an Escherichia coli outer membrane protein, in the secretion of heat-stable enterotoxin I across the outer membrane. Microb. Pathogen. 25 111-120. 

Hughes, J. M., Murad, F., Chang, B., and Guerrant, R. L., 1978, Role of cyclic GMP in the action of heat-stable enterotoxin of Escherichia coli, Nature 271 755. 

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