Hainantoxin-Ⅵ, A Novel Tarantula Neurotoxin Inhibiting Insect Voltage-gated Sodium Channel Inactivation
- VernacularTitle:海南捕鸟蛛毒素-Ⅵ,一种新型的抑制昆虫电压门控钠通道失活的狼蛛神经毒素
- Author:
Ruilan WANG
;
Jianyi PAN
;
Yucheng XIAO
;
Meichi WANG
;
Songping LIANG
- Publication Type:Journal Article
- Keywords:
spider neurotoxin;
dorsal unpaired median (DUM) neuron;
sodium channel
- From:
Chinese Journal of Biochemistry and Molecular Biology
2008;24(9):796-802
- CountryChina
- Language:Chinese
-
Abstract:
The neurotoxin peptide, hainantoxin-Ⅵ (HNTX- Ⅵ), has been isolated from the venom of Chinese tarantula Ornithoconus hainana by a combination of ion exchange chromatography and reverse phase HPLC. The toxin was found to contain 34 amino acid residues with 6 conserved cysteine residues. The effects of HNTX-VI on voltage-gated sodium channels were studied via whole-cell patch clamp techniques. Although several inhibitors of mammalian neuronal sodium channel activation (hainantoxin Ⅰ-Ⅴ) had been characterized from the same venom, the present study indicated that HNTX-Ⅵ had the ability to slow the inactivation kinetics of the sodium channels in Cockroach Periplaneta Americana dorsal unpaired median (DUM) neurons in a similar manner to δ-atractoxins. After HNTX-Ⅵ treatment, steady-state sodium channel inactivation became incomplete, leading to a non-inactivating component at potentials more positive than - 55 mV. The novel function of the tarantula toxin HNTX-Ⅵ not only supplies a useful tool for exploring the gating mechanisms of sodium channels but also provides theoretical foundations for exploiting novel and safe insecticides.
