Scorpion venom contains diverse bioactive peptides that can recognize and interact with membrane proteins such as ion channels. These natural toxins are believed to be useful tools for exploring the structure and function of ion channels. In this study, we characterized a K+-channel toxin gene, ImKTx96, from the venom gland cDNA library of the scorpion Isometrus maculates. The peptide deduced from the ImKTx96 precursor nucleotide sequence contains a signal peptide of 27 amino acid residues and a mature peptide of 29 residues with three disulfide bridges. Multiple sequence alignment indicated that ImKTx96 is similar with the scorpion toxins that typically target K+-channels. The recombined ImKTx96 peptide (rImKTx96) was expressed in the Escherichia coli system, and purified by GST-affinity chromatography and RP-HPLC. Results from whole-cell patch-clamp experiments revealed that rImKTx96 can inhibit the current of the Kv1.2 ion channel expressed in HEK293 cells. The 3D structure of ImKTx96 was constructed by molecular modeling, and the complex formed by ImKTx96 interacting with the Kv1.2 ion channel was obtained by molecular docking. Based on its structural features and pharmacological functions, ImKTx96 was identified as one member of K+-channel scorpion toxin α-KTx10 group and may be useful as a molecular probe for investigating the structure and function of the Kv1.2 ion channel.

中文翻译：

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ImKTx96是蝎Isometrus有毒的Kv1.2离子通道的肽阻滞剂。

蝎毒含有多种生物活性肽，可以识别并与膜蛋白（例如离子通道）相互作用。这些天然毒素被认为是探索离子通道结构和功能的有用工具。在这项研究中，我们从蝎Isometrus的毒液腺cDNA文库中表征了一个K +通道毒素基因ImKTx96。从ImKTx96前体核苷酸序列推导的肽含有27个氨基酸残基的信号肽和具有3个二硫键的29个残基的成熟肽。多序列比对表明ImKTx96与通常靶向K +通道的蝎毒素相似。重组的ImKTx96肽（rImKTx96）在大肠杆菌系统中表达，并通过GST亲和色谱和RP-HPLC纯化。全细胞膜片钳实验的结果表明，rImKTx96可以抑制HEK293细胞中表达的Kv1.2离子通道的电流。通过分子建模构建ImKTx96的3D结构，并通过分子对接获得ImKTx96与Kv1.2离子通道相互作用形成的复合物。基于其结构特征和药理功能，ImKTx96被确定为K +通道蝎毒素α-KTx10组的成员之一，可作为研究Kv1.2离子通道结构和功能的分子探针。通过分子对接获得2个离子通道。根据其结构特征和药理作用，ImKTx96被确定为K +通道蝎毒素α-KTx10组的成员之一，可作为研究Kv1.2离子通道结构和功能的分子探针。通过分子对接获得2个离子通道。根据其结构特征和药理作用，ImKTx96被确定为K +通道蝎毒素α-KTx10组的成员之一，可作为研究Kv1.2离子通道结构和功能的分子探针。