Mechanisms of maurotoxin action on shaker potassium channels
Mechanisms of maurotoxin action on shaker potassium channels
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DOI：
10.1016/s0006-3495(00)76335-1
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发表时间：
2000-08-01
影响因子：
3.4
通讯作者：
Hoshi, T
中科院分区：
文献类型：
--
作者：
Avdonin, V;Nolan, B;Hoshi, T
Maurotoxin（α-KTx 6.2）是一种来源于突尼斯蝎形蝎Scorpio maurus palmatus的毒素，并且它是含有四个二硫键的新毒素家族的成员（Selisko等人，1998，fur. J，Biochem.254：468-479），我们研究了黑尾鲨毒素对爪蟾卵母细胞中表达的电压门控K+通道的作用机制。黑尾鲨毒素以电压依赖性方式阻断通道，其效力随着更大的超极化而增加。我们表明，已知参与其他肽毒素作用的通道孔段的外口中的氨基酸残基也参与黑尾鲨毒素与通道的相互作用。我们的结论是，尽管不寻常的二硫键模式，maurotoxin行动的机制是类似的其他K+通道毒素只有三个二硫键。
Maurotoxin (alpha-KTx6.2) is a toxin derived from the Tunisian chactoid scorpion Scorpio maurus palmatus, and it is a member of a new family of toxins that contain four disulfide bridges (Selisko et ai,, 1998, fur. J, Biochem. 254:468-479), We investigated the mechanism of the maurotoxin action on voltage-gated K+ channels expressed in Xenopus oocytes, Maurotoxin blocks the channels in a voltage-dependent manner, with its efficacy increasing with greater hyperpolarization, We show that an amino acid residue in the external mouth of the channel pore segment that is known to be involved in the actions of other peptide toxins is also involved in maurotoxin's interaction with the channel. We conclude that, despite the unusual disulfide bridge pattern, the mechanism of the maurotoxin action is similar to those of other K+ channel toxins with only three disulfide bridges.