Birtoxin
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| Birtoxin | |
|---|---|
| Category | Ion channel toxin, Neurotoxin |
| Species | Parabuthus transvaalicus[1] |
| Target | voltage-gated sodium channel[1] |
| Symptoms | tachypnea, convulsions, tremors, death |
| Taxonomic ID | 170972 [1] |
| Sequence length | 58 AA [1] |
Birtoxin is a neurotoxin from the venom of the South African Spitting scorpion (Parabuthus transvaalicus). By changing sodium channel activation, the toxin promotes spontaneous and repetitive firing much like pyrethroid insecticides do
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Birtoxin was isolated from the venom of the South African Spitting scorpion.[1] It is a peptide that is moderately toxic but very abundant in the venom.[1] Other peptide toxins found in the venom include: dortoxin, a lethal peptide; bestoxin, which causes writhing in mice; and altitoxin, a highly depressant peptide.[2]
Chemistry
Generally, peptide neurotoxins can be divided into two major families, the ‘long chain neurotoxins’ (LCN) with 60- to 70-residue range and known to contain eight cysteine residues; and the ‘short chain neurotoxins’ (SCN) with 30 to 40 peptides with six or eight cysteine residues. Birtoxin, together with other birtoxin-like peptides including bestoxin, is 58 amino-acid residues long, close to the ‘long chain’ family but with six cysteine residues. Birtoxin is reticulated by three disulfide bridges, instead of four, compared to other LCNs .[3] Therefore, it is considered to be the evolutionary link between ‘long chain’- and ‘short chain’- families.[4][5][6][7]
