Hainantoxin-Ⅵ, A Novel Tarantula Neurotoxin Inhibiting Insect Voltage-gated Sodium Channel Inactivation / 中国生物化学与分子生物学报
Chinese Journal of Biochemistry and Molecular Biology
;
(12): 796-802, 2008.
Article
in Chinese
| WPRIM
| ID: wpr-410144
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.
Full text:
Available
Index:
WPRIM (Western Pacific)
Language:
Chinese
Journal:
Chinese Journal of Biochemistry and Molecular Biology
Year:
2008
Type:
Article
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