Altitoxin
 | This article relies on a single source. (March 2018) |
Altitoxin is a neurotoxin found in the South African scorpion Parabuthus transvaalicus. Injection of altitoxin in mice leads to akinesia, depression and death.[1]
Sources
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Altitoxin is secreted by the venom gland of the South African spitting (or fattail) scorpion Parabuthus transvaalicus.[1]
Chemistry
[edit]Altitoxin, with the amino acid sequence ADVPGNYPLDKDGNTYTCLELGENKDCQKVCKLHGVQYGYCYAFFCWCKELDDKDVSV, is 58 amino acid residues long and has a molecular mass of 6598 Da; it has 3 disulfide bridges (Cys18-Cys41, Cys27-Cys46, and Cys31-Cys48).[1] It has large homology to other toxins from the venom of Parabuthus transvaalicus, including bestoxin, birtoxin, ikitoxin and dortoxin.
Target
[edit]Altitoxin has sequence homology to scorpion β-toxins, suggesting it might target sodium channels. However, its depressing action following injection into mice [1] is not in agreement with the effect of β-toxins on sodium channels. Related scorpion toxins, which include birtoxin and bestoxin, exhibit highly divergent biological activity,[1] indicating that the mode of action of these toxins is highly diverse.
Toxicity
[edit]An injection of 100 ng altitoxin in 20 g mouse (ED99) causes a state of akinesia and depression. Lethality is reached at injecting 200 ng.[1]
References
[edit]- 1 2 3 4 5 6 Inceoglu, B.; Lango, J.; Pessah, I. N.; Hammock, B. D. (2005). "Three structurally related, highly potent, peptides from the venom of Parabuthus transvaalicus possess divergent biological activity". Toxicon. 45 (6): 727–33. Bibcode:2005Txcn...45..727I. doi:10.1016/j.toxicon.2005.01.020. PMID 15804521.