Agelenin
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| Other names
U1-agatoxin-Aop1a, U1-AGTX-Aop1a
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3D model (JSmol)
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| Properties | |
| Molar mass | 3500 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Agelenin (toxicologically named as U1-agatoxin-Aop1a[1] and abbreviated as U1-AGTX-Aop1a) is a neurotoxic peptide isolated from the venom of the spider Allagelena opulenta which consists of 35 amino acids. It is an antagonist of the presynaptic P-type calcium channel in insects.
Sources
[edit]Agelenin is an insecticidal toxin of the venom of the species Allagelena opulenta.[1] It was first discovered in 1990.[2]
Chemistry
[edit]Agelenin consists of a polypeptide chain of 35 amino acid residues.[2] It has a short anti-parallel β-sheet connected by three disulfide bonds and four β-turns that form the compact core structure. The three amino acid residues that are thought to be essential for the inhibiting activity of agelenin are Phe9, Ser28 and Arg33.[3]
The structure of agelenin is similar to the structure of ICK toxins like ω-Aga-IVA and ω-ACTXHv1a in that they all consist of three disulfide bonds with the same bonding pattern. An important difference between agelenin and ω-Aga-IVA and ω-ACTXHv1a is that ω-Aga-IVA and ω-ACTXHv1a have functional C-terminal tails.[3]
Agelenin belongs to toxin group of agatoxins.[1] The amino acid structure of agelenin is Gly-Gly-Cys-Leu-Pro-His-Asn-Arg-Phe-Cys-Asn-Ala-Leu-Ser-Gly-Pro-Arg-Cys-Cys-Ser-Gly-Leu-Lys-Cys-Lys-Glu-Leu-Ser-Ile-Trp-Asp-Ser-Arg-Cys-Leu (GGCLPHNRFCNALSGPRCCSGLKCKELSIWDSRCL).[3]
Target
[edit]Agelenin is directed against P-subtype calcium channels in insects.[4]
Toxicity
[edit]Agelenin is not toxic in mammals, but has a PD50 of 291 pmol/g in crickets where it causes rapid, reversible paralysis.[3] In preparations of neuromuscular junctions of lobsters agelenin causes a non-reversible paralysis due to the suppression of excitatory postsynaptic potentials, presumably by inhibition of the presynaptic calcium influx.[2]
References
[edit]- ^ a b c Institute for Molecular Bioscience. (2010) “U2-agatoxin-Aop1a”, Arachnoserver. Accessed on: 11 October 2015.
- ^ a b c Hagiwara, K., Sakai, T., Miwa, A., Kawai, N. and Nakajima, T. (1990). "Complete amino acid sequence of a new type of neurotoxin from the venom of the spider, Agelena opulenta". BioMed Research International. 11: 181–186. doi:10.2220/biomedres.11.181.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b c d Yamaji, N., Sugase, K., Nakajima, T., Miki, T., Wakamori, M., More, Y. and Iwashita, T. (2007). "Solution structure of agelenin, an intisecticidal peptide isolated from the spider Agelena opulenta, and its structural similarities to insect-specific calcium channel inhibitors". FEBS Letters. 581 (20): 3789–3794. Bibcode:2007FEBSL.581.3789Y. doi:10.1016/j.febslet.2007.06.077. PMID 17644092.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Rash, L.D. and Hodgson, W.C. (2002). "Pharmacology and biochemistry of spider venoms". Toxicon. 40 (3): 225–254. Bibcode:2002Txcn...40..225R. doi:10.1016/S0041-0101(01)00199-4. PMID 11711120.
{{cite journal}}: CS1 maint: multiple names: authors list (link)