Formulation: Each vial contains 1 mg of cholera toxin (CT). When reconstituted to 0.5 ml with water, the buffer is 0.05 M Tris, 0.2 M NaCl, 0.001 M Na2EDTA at pH 7.5
Purity: ≥95% (estimated by SDS-PAGE)
Shelf life (days): 730
Notes: Cholera toxin is produced by V. cholerae and is a multimeric enterotoxin that consists of a single A subunit surrounded by five B subunits.{31319} Following binding to the membrane of enteric cells, the toxin is endocytosed and travels to the endoplasmic reticulum where the enzymatically active A subunit (CTA1) is translocated to the cytosol. Within the cytosol, CTA1 catalyzes the ADP-ribosylation of the Gsα protein, which activates adenylate cyclase, locking it in an ‘on’ position.{31320} The increased intracellular concentration of cAMP causes hypersecretion of chloride and bicarbonate ions, which results in increased fluid secretion and severe diarrhea characteristic of the disease cholera.{31319}