Hongotoxin
Hongotoxin (HgTX) is an ion channel toxin, which blocks Shaker-type (Kv1) K+ channels. The toxin is derived from the venom of Centruroides limbatus,[1] a Central American scorpion found meanly in Costa Rica, Honduras and Panama.[2]
Chemistry
Hongotoxin belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 2 subfamily.[1]
There are five subtypes known of the hongotoxin peptide. HgTX1 is 39 amino acids long and shows an overall amino acid sequence homology of 89% to margatoxin (MgTX).[1]
Target
Hongotoxin (HgTX) targets are Shaker-type (Kv1) K+ channels.
HgTX1 shows high affinity with Kv1.1, Kv1.2, Kv1.3 voltage-gated potassium channels, but much lower affinity with Kv1.6 (see table 1 and 2[1]).
HgTX2,[3] HgTX3,[4] HgTX4[5] and HgTX5[6] are potent selective inhibitors of Kv1 voltage-gated potassium channels (By similarity).
| table 1 | IC50 | |||
|---|---|---|---|---|
| Kv1.1 | Kv1.2 | Kv1.3 | Kv1.6 | |
| HgTX1 | 31 | 170 | 86 | 6,000 |
| MgTx | 144 | 675 | 230 | ND |
ND, not determined. All measurements in pM
| table 2 | Ki | |||
|---|---|---|---|---|
| Kv1.1 | Kv1.2 | Kv1.3 | Kv1.6 | |
| HgTX1 | 0.08 | 0.09 | 0.24 | 8.7 |
| MgTx | 0.52 | 0.21 | 0.31 | 9.4 |
All measurements in pM
Mode of action
The mode of action is not yet known.[citation needed]
References
- ^ a b c d Koschak A, Bugianesi RM, Mitterdorfer J, Kaczorowski GJ, Garcia ML, Knaus HG (January 1998). "Subunit composition of brain voltage-gated potassium channels determined by hongotoxin-1, a novel peptide derived from Centruroides limbatus venom". The Journal of Biological Chemistry. 273 (5): 2639–44. doi:10.1074/jbc.273.5.2639. PMID 9446567.
- ^ Rein, Jan Ove. "Centruroides limbatus". The Scorpion Files.
- ^ Hongotoxin-2
- ^ Hongotoxin-3
- ^ Hongotoxin-4
- ^ Hongotoxin-5
External links
- Pragl B, Koschak A, Trieb M, et al. (2002). "Synthesis, characterization, and application of cy-dye- and alexa-dye-labeled hongotoxin(1) analogues. The first high affinity fluorescence probes for voltage-gated K+ channels". Bioconjugate Chemistry. 13 (3): 416–25. doi:10.1021/bc015543s. PMID 12009929.
Content Disclaimer
Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.
- The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
- There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
- It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
- Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
- Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.