蝎毒素BmK M2的分离鉴定及其电生理活性研究

从东亚钳蝎蝎毒中分离鉴定出新型的Na⁺通道毒素，采用Sephadex-G-50分子筛、高效液相色谱、多肽指纹图谱及氨基酸测序等技术从野生东亚钳蝎毒液中分离鉴定了一种长链多肽毒素BmK M2，其相对分子质量为7 235.5，由64个氨基酸组成，包含4对二硫键。序列比对显示，BmK M2的序列与已发现的Na⁺通道毒素BmK M1、BmK M3、BmK M9等具有较高的序列和结构相似性，是一种潜在的新型Na⁺通道调节剂。全细胞膜片钳实验结果显示，BmK M2可显著增强电压门控Na⁺通道Nav1.7的激活，延迟Nav1.7的稳态失活及关闭状态失活，但对Nav1.8无活性。实验结果表明BmK M2可作为一种新型的Na⁺通道探针，用于Nav1.7结构功能研究以及靶向药物的开发。

Isolation, identification and electrophysiological activity of BmK M2 from Buthus martensii Karsch venom

This study aimed to isolate and identify novel toxin peptides targeting voltage-gated sodium channels (VGSGs) from the venom of the Buthus martensii Karsch (BmK) scorpion. Using G50-gel filtration, HPLC, peptide fingerprinting and amino acid sequencing, a novel sodium channel modulator, BmK M2, was identified from BMK scorpion. BmK M2 is a relatively abundant long chain polypeptide toxin in BmK scorpion venom with a molecular weight of 7 235.59, consisting of 64 amino acids and 4 pairs of disulfide bonds.Sequence alignment showed that the amino acid sequence of BmK M2 had high sequence and structural similarity to that of the discovered sodium channel toxins of BmK M1, BmK M3 and BmK M9, etc.BmK M2 is a potential new sodium channel modulator.Electrophysiological results revealed that BmK M2 can significantly enhance the activation, delay the steady-state inactivation and closed-state inactivation of Nav1.7, but has no activity on Nav1.8.BmK M2 can be used as a novel peptide probe for the study of the structure and function of Nav1.7 and the development of drugs targeting Nav1.7.