Maitotoxin

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Maitotoxin
Space-filling model of the maitotoxin molecule
Identifiers
CAS number [59392-53-9]
Properties
Molecular formula C164H256O68S2Na2
Molar mass 3422 g/mol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Maitotoxin or MTX is an extremely potent toxin produced by Gambierdiscus toxicus, a dinoflagellate species partially responsible for the phenomenon known as red tide. Maitotoxin is so potent that it has been demonstrated that an intraperitoneal injection of 0.13 µg/kg was lethal in mice.[1] Maitotoxin was named from the ciguateric fish Ctenochaetus striatus—called “maito” in Tahiti—from which maitotoxin was isolated for the first time - later it was shown that maitotoxin is actually produced by Gambierdiscus toxicus.

Maitotoxin activates Ca2+ permeable, non-selective cation channels, leading to an increase in levels of cytosolic Ca2+ ions. It is thought that maitotoxin leads to the formation of pores on these ion channels. Ultimately, a cell death cascade is activated, resulting in membrane blebbing and eventually cell lysis. Maitotoxin is known to activate cytosolic calcium-activated proteases calpain-1 and calapin-2, contributing to necrosis [2]. The toxicity of maitotoxin to mice is the highest in nonprotein toxins: the LD50 is 50 ng/kg.

The molecule itself exists as a system of 32 fused rings. It is notable because it is one of the largest, and most complex, non-protein or non-polysaccharide molecule produced by an organism. Maitotoxin includes 32 ether rings, 22 methyls, 28 hydroxyls, and 2 sulfuric acid esters and has an amphipathic structure. Its structure was established through analysis using nuclear magnetic resonance at Tohoku University, Harvard and the University of Tokyo in combination with mass spectroscopy, and synthetic chemical methods.

[edit] References

 The references in this article would be clearer with a different or consistent style of citation, footnoting, or external linking.
  1. ^ Yokoyama, A et al (1988). "Some Chemical Properties of Maitotoxin, a Putative Calcium Channel Agonist Isolated from a Marine Dinoflagellate". J. Biochem 104 (2): 184–187. ISSN: 0021-924X. 
  2. ^ Estacion, M and Schilling, WP (2001). "Maitotoxin-induced membrane blebbing and cell death in bovine aortic endothelial cells". BMC Physiology 1 (2). doi:10.1186/1472-6793-1-2. 
  3. ^ Murata, M et al (2001). "Structure and partial stereochemical assignments for maitotoxin, the most toxic and largest natural non-biopolymer". J. Am. Chem. Soc. 116 (16): 7098–7107. doi:10.1021/ja00095a013. 
  4. ^ Sasaki, M et al (1996). "The complete structure of maitotoxin, I; Configuration of the C1-C14 side chain". Angew. Chem. Int. Ed. Engl. 35: 1672–1675. doi:10.1002/anie.199616721. ISSN: 0570-0833. 
  5. ^ Kishi, Y (1998). "Complete structure of maitotoxin". Pure & Appl. Chem. 70 (2): 339–344. doi:10.1351/pac199870020339. 
  6. ^ Jones, Matland (2004). Organic Chemistry, Third Edition. W. W. Norton & Company. ISBN 978-0393924084. 
  7. ^ Wang, K. et al (1996). "Maitotoxin induces calpain activation in SH-SY5Y neuroblastoma cells and cerebrocortical cultures". Arch. Biochem. Biophys. 331: 208–214. doi:10.1006/abbi.1996.0300. ISSN: 0003-9861.