title: Functional characterization of two novel scorpion sodium channel toxins from Lychas mucronatus.
abstract: The diverse α-scorpion toxins are invaluable pharmacological tools and potential drugs targeting sodium channels, but the pharmacological profiles of most toxins remains unknown so far. Here, we reported pharmacological activities of two novel α-scorpion toxins LmαTX3 and LmαTX5 from the Lychas mucronatus. Using the expression vector pET-28a, the recombinant LmαTX3 and LmαTX5 were separated by RP-HPLC and identified by MALDI-TOF-MS. Subsequently, sodium channels rNav1.2, mNav1.4, hNav1.5 and hNav1.7 were used for evaluating the pharmacological activities of LmαTX3 and LmαTX5 toxins. The electrophysiological experiments showed that both 10 μM recombinant LmαTX3 and LmαTX5 seriously inhibited the fast inactivation of mNav1.4 and hNav1.5 channels, moderately affected hNav1.7 channel, and hardly modulated rNav1.2 channel. The dose-response experiments further indicated the EC50 values of LmαTX3 were 4.98 ± 0.79 μM for mNav1.4, 1.23 ± 0.31 μM for hNav1.5 and 31.46 ± 2.32 μM for hNav1.7 channels, respectively. Similar pharmacological profiles of recombinant LmαTX5 were also observed, and its EC50 values were 4.53 ± 1.38 μM, 1.03 ± 0.43 μM and 67.62 ± 2.31 μM for mNav1.4, hNav1.5 and hNav1.7, respectively. In addition, the recombinant LmαTX3 from the vector pET-14b had much less effect on the fast inactivation of mNav1.4, hNav1.5 and hNav1.7 channels, which indicated that the expression vector pET-14b likely played a critical role in toxin function. Together, these findings first highlighted that scorpion toxins from L. mucronatus were a new molecular resource of discovering pharmacological probes and prospective drugs targeting sodium channels in the future.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: xulingna58@126.com.
authors.forename: Lingna
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: fiona2210@163.com.
authors.forename: Tian
authors.initials: T
authors.lastname: Li
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: honglianliu2011@whu.edu.cn.
authors.forename: Honglian
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address: y_fan@whu.edu.cn.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, PR China. Electronic address: liangsp@hunnu.edu.cn.
authors.forename: Songping
authors.initials: S
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China; Center for BioDrug Research, Wuhan University, Wuhan 430072, PR China. Electronic address: zjcao@whu.edu.cn.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China; Center for BioDrug Research, Wuhan University, Wuhan 430072, PR China. Electronic address: liwxlab@whu.edu.cn.
authors.forename: Wenxin
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, PR China; Center for BioDrug Research, Wuhan University, Wuhan 430072, PR China. Electronic address: ylwu@whu.edu.cn.
authors.forename: Yingliang
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA; D008969:Molecular Sequence Data; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry* / Q000494:pharmacology; D012605:Scorpions; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000187:drug effects*
chemical_list: D012604:Scorpion Venoms; D015222:Sodium Channels; D004247:DNA
keywords: Expression and purification; LmαTX3; LmαTX5; Lychas mucronatus; Pharmacological profile; Sodium channels