Hongotoxin

Hongotoxin (HgTX) is an ion channel toxin, which blocks "Shaker"-type (K_v1) K⁺ channels.

ource

Centruroides limbatus Citation
last =Koschak
first =A
date =
year =
title =Subunit composition of brain voltage-gated potassium channels determined by hongotoxin-1, a novel peptide derived from Centruroides limbatus venom.
publisher =J. Biol. Chem.
publication-date =January 30,1998
volume = Vol. 273
pages = 2639-2644] , a Central American scorpion found meanly in Costa Rica, Honduras and Panama. [ [http://www.ub.ntnu.no/scorpion-files/c_limbatus.php scorpion files] ]

Chemistry

Hongotoxin belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 2 subfamily.

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).

Target

Hongotoxin (HgTX) targets are "Shaker"-type (K_v1) K⁺ channels.

HgTX₁ shows high affinity with K_v1.1, K_v1.2, K_v1.3 voltage-gated potassium channels, but much lower affinity with K_v1.6 (see table 1 and 2).

HgTX₂ [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=34925057 Hongotoxin-2] ] , HgTX₃ [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=34925059 Hongotoxin-3] ] , HgTX₄ [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=34925062 Hongotoxin-4] ] and HgTX₅ [ [http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=protein&id=34925065 Hongotoxin-5] ] are potent selective inhibitors of Kv1 voltage-gated potassium channels ( [http://www.qsarworld.com/insilico-chemistry-similarity-principle.php/ By similarity] ).

ND, not determined. All measurements in "pM"All measurements in "pM"

Mode of action

The mode of action is not yet known.

References