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  • E8656 - Heat-Labile Enterotoxin, B subunit (LTB) from E. coli

E8656 Sigma

Heat-Labile Enterotoxin, B subunit (LTB) from E. coli

recombinant, expressed in Pichia pastoris, >90% (SDS-PAGE), lyophilized powder

Synonym: LTB



Related Categories Bacteria-derived adjuvants, Bioactive Small Molecule Alphabetical Index, Bioactive Small Molecules, Cell Biology, Cell Culture,
recombinant   expressed in Pichia pastoris
assay   >90% (SDS-PAGE)
form   lyophilized powder
shipped in   wet ice
storage temp.   2-8°C


Analysis Note

The activity is measured by ELISA using ganglioside GM1-coated plates (Cat. No. G7641). LTB at various concentrations is incubated on the ganglioside GM1 coated wells, followed by anti-cholera toxin antibody (Cat. No. C3062), and peroxidase-labeled goat anti-rabbit IgG (Cat.No. A0545) as the secondary antibody. Binding saturation of 50% may be achieved with = 0.12 μg/mL of LTB.

Physical form

Lyophilized from a solution containing Heat-Labile Enterotoxin, B subunit in 0.05 M Tris buffer, pH 7.5, 0.2 M NaCl, 3 mM NaN3, and 1 mM sodium EDTA.

Biochem/physiol Actions

Enterotoxigenic Escherichia coli causes diarrhea through its heat-labile enterotoxin (LT). The LT is a periplasmic protein composed of one A subunit (LTA, 27 kDa) and five non-covalently associated B subunits (LTB, 11.6 kDa each) forming a ring-like pentamer. LTB has high affinity towards the toxin receptor ganglioside GM1, a glycosphingolipid found ubiquitously on the surface of mammalian cells. Ganglioside GM1 facilitates the delivery of the A subunit to the cytosol of the target cell resulting in persistent synthesis of cAMP and subsequently diarrhea. This characteristic makes LTB a good label for microglial cells (due to the enrichment of ganglioside GM1 on their cell surface). In addition, studies made mostly with animal models demonstrated that recombinant LTB could stimulate strong serum and mucosal immune responses against LT. Other studies have indicated that LTB could be used as a potent mucosal adjuvant.

Features and Benefits

This compound is a featured product for Cyclic Nucleotide research. Click here to discover more featured Cyclic Nucleotide products. Learn more about bioactive small molecules for other areas of research at sigma.com/discover-bsm.

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Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Precautionary statements 
NONH for all modes of transport
WGK Germany 
Protocols & Articles


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