摘要
通过阳离子交换和反相HPLC柱层析从海南捕鸟蛛(Ornithoconus hainana)粗毒中分离到一种新型的神经毒素,海南捕鸟蛛毒素-Ⅵ(HNTX-Ⅵ),由34个氨基酸残基组成,含有6个保守的半胱氨酸残基.运用全细胞膜片钳技术,研究了HNTX-Ⅵ对电压门控钠通道的影响.先前从海南捕鸟蛛粗毒中分离到的几种毒素,具有抑制哺乳动物钠通道激活的特性.本文研究结果表明,HNTX-Ⅵ能以类似于δ-atractoxins作用方式延缓蜚蠊背侧不成对中间(dorsal unpaired median,DUM)神经细胞的钠通道的失活,且导致钠通道稳态失活变得不完全,在预钳制电压大于-55 mV时形成不完全失活结构.HNTX-Ⅵ的这种新的功能不仅为探索钠通道的门控机制提供了有用的工具,也为开发新的安全的杀虫剂提供理论基础.
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.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2008年第9期796-802,共7页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金(No.30500146)
国家重点基础研究发展规划(973计划)项目(No.2006CB708508)资助~~
