cholera toxin

Cholera toxin, a multifunctional protein produced by Vibrio cholera, does not just cause cholera but also able to influence the immune system in many ways.

Cholera toxin B subunit (from vibrio cholerae) is non-toxic to cells and lacks inherent adenylate cyclase activity. It adheres to cells by binding to ganglioside GM1.8. Research indicates that this subunit is an excellent marker for microglia due to their surface richness in ganglioside GM1, though it is not as effective for oligodendrocytes or astrocytes. Additionally, CTB is reported to be an excellent tracer for studying axonal transport using immunohistochemistry and has been widely used as a marker for membrane lipid rafts.

Iobenguane sulfate (MIBG sulfate) is a high-affinity substrate for cholera toxin that disrupts cellular mono(ADP-ribosylation). Radioiodinated Iobenguane sulfate is used clinically as a tumor-targeted radiopharmaceutical for diagnosing and treating adrenergic tumors.

Ganglioside GM1is a monosialylated ganglioside and the prototypic ganglioside for those containing one sialic acid residue.1,2It is found in a large variety of cells, including immune cells and neurons, and is enriched in lipid rafts in the cell membrane.3It associates with growth factor receptors, including TrkA, TrkB, and the GDNF receptor complex containing Ret and GFRα, and is required for TrkA expression on the cell surface. Ganglioside GM1interacts with other proteins to increase calcium influx, affecting various calcium-dependent processes, including inducing neuronal outgrowth during differentiation. Ganglioside GM1acts as a receptor for cholera toxin, which binds to its oligosaccharide group, facilitating toxin cell entry into epithelial cells of the jejunum.4,5Similarly, it is bound by the heat-labile enterotoxin fromE. coliin the pathogenesis of traveler's diarrhea.6Ganglioside GM1gangliosidosis, characterized by a deficiency in GM1-β-galactosidase, the enzyme that degrades ganglioside GM1, leads to accumulation of the gangliosides GM1and GA1in neurons and can be fatal in infants.1Levels of ganglioside GM1are decreased in the substantia nigra pars compacta in postmortem brain from patients with Parkinson's disease.3Ganglioside GM1mixture contains a mixture of ovine ganglioside GM1molecular species with primarily C18:0 fatty acyl chain lengths, among various others. [Matreya, LLC. Catalog No. 1544] 1.Kolter, T.Ganglioside biochemistryISRN Biochem.506160(2012) 2.Mocchetti, I.Exogenous gangliosides, neuronal plasticity and repair, and the neurotrophinsCell Mol. Life Sci.62(19-20)2283-2294(2005) 3.Ledeen, R.W., and Wu, G.The multi-tasked life of GM1 ganglioside, a true factotum of natureTrends Biochem. Sci.40(7)407-418(2015) 4.Turnbull, W.B., Precious, B.L., and Homans, S.W.Dissecting the cholera toxin-ganglioside GM1 interaction by isothermal titration calorimetryJ. Am. Chem. Soc.126(4)1047-1054(2004) 5.Blank, N., Schiller, M., Krienke, S., et al.Cholera toxin binds to lipid rafts but has a limited specificity for ganglioside GM1Immunol. Cell Biol.85(5)378-382(2007) 6.Minke, W.E., Roach, C., Hol, W.G., et al.Structure-based exploration of the ganglioside GM1 binding sites of Escherichia coli heat-labile enterotoxin and cholera toxin for the discovery of receptor antagonistsBiochemistry38(18)5684-5692(1999)

GM1a Ganglioside oligosaccharide, a semisynthetic derivative of ganglioside GM1, serves as the natural receptor for cholera toxin and is crucial for both general growth regulation and the coupling of hormone-induced responses [1].

Endo CNTinh-03 effectively inhibits the increase of cAMP and cGMP triggered by agonists such as G protein-coupled receptors, adenylate cyclase, and guanylate cyclase, with an IC50 of 4 μM. It also blocks the chloride ion currents induced by cholera toxin and Escherichia coli (STa) toxins, alleviates secretory diarrhea in mouse models, and prevents cyst growth in models of polycystic kidney disease.

CTB (Cholera Toxin B subunit) is an activator of p300 histone acetyltransferase and induces apoptosis in MCF-7 cells.

Ganglioside GM1-binding peptide sp3 is a synthetically engineered peptide that specifically binds to the pentasaccharide region of GM1 ganglioside. The dynamic transitions of Ganglioside GM1-binding peptide sp3 may play a crucial role in the functions of GM1 as a receptor for various ligands, such as in the conventional pathway of cholera toxin infection. This peptide is useful for studies on the interactions between GM1 and its ligands.