Zhou Maojun, Wang Lei, Wu Yun, Liu Junliang, Sun Dandan, Zhu Xiaoyan, Feng Yuchao, Qin Mengying, Chen Shangwu, Xu Anlong
State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; State Key Laboratory of Biocontrol, Shenzhen R&D Center, People's Republic of China.
Toxicon. 2015 May;98:5-11. doi: 10.1016/j.toxicon.2015.01.009. Epub 2015 Jan 16.
A peptide toxin, lt16a, from the venom of the worm-hunting Conus litteratus, shares the typical signal peptide sequences of M-superfamily conotoxins, which usually contain six cysteine residues that are arranged in a CC-C-C-CC pattern. Interestingly, lt16a comprises 21 amino acid residues in its mature region and has a cysteine framework XVI, which is arranged in a C-C-CC pattern. The coding region of lt16a was cloned into the pTRX vector and the fusion protein was overexpressed in Escherichia coli. After cleaving the fusion protein and purifying the protein lt16a using chromatography, the mass of lt16a was found by mass spectrometry to be consistent with the expected mass of 2357.7 Da. Whole-cell patch clamp experiments demonstrated that lt16a could inhibit both the TTX-sensitive and TTX-resistant sodium currents in adult rat dorsal root ganglion neurons. The inhibition of lt16a on TTX-resistant sodium currents was stronger than on TTX-sensitive sodium currents. To our knowledge, this is the first report of a framework XVI conotoxin that can inhibit voltage-gated sodium channel currents in mammalian sensory neurons. This report helps facilitates an understanding of the sequence diversity of conotoxins.
一种来自捕食蠕虫的织锦芋螺毒液的肽毒素lt16a，具有M超家族芋螺毒素典型的信号肽序列，该序列通常包含六个以CC-C-C-CC模式排列的半胱氨酸残基。有趣的是，lt16a的成熟区域由21个氨基酸残基组成，具有以C-C-CC模式排列的半胱氨酸框架XVI。将lt16a的编码区克隆到pTRX载体中，并在大肠杆菌中过表达融合蛋白。在裂解融合蛋白并使用色谱法纯化lt16a蛋白后，通过质谱法发现lt16a的质量与预期的2357.7 Da质量一致。全细胞膜片钳实验表明，lt16a可以抑制成年大鼠背根神经节神经元中TTX敏感和TTX抗性的钠电流。lt16a对TTX抗性钠电流的抑制作用强于对TTX敏感钠电流的抑制作用。据我们所知，这是关于一种能够抑制哺乳动物感觉神经元电压门控钠通道电流的框架XVI芋螺毒素的首次报道。本报告有助于促进对芋螺毒素序列多样性的理解。
