Wang Lei, Pi Canhui, Liu Junliang, Chen Shangwu, Peng Can, Sun Dandan, Zhou Maojun, Xiang Hui, Ren Zhenghua, Xu Anlong
State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, Department of Biochemistry, College of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou, 510275, People's Republic of China.
J Pept Sci. 2008 Oct;14(10):1077-83. doi: 10.1002/psc.1044.
A novel conotoxin named lt6c, an O-superfamily conotoxin, was identified from the cDNA library of venom duct of Conus litteratus. The full-length cDNA contains an open reading frame encoding a predicted 22-residue signal peptide, a 22-residue proregion and a mature peptide of 28 amino acids. The signal peptide sequence of lt6c is highly conserved in O-superfamily conotoxins and the mature peptide consists of six cysteines arranged in the pattern of C-C-CC-C-C that is defined the O-superfamily of conotoxins. The mature peptide fused with thioredoxin, 6-His tag, and a Factor Xa cleavage site was successfully expressed in Escherichia coli. About 12 mg lt6c was purified from 1L culture. Under whole-cell patch-clamp mode, lt6c inhibited sodium currents on adult rat dorsal root ganglion neurons. Therefore, lt6c is a novel O-superfamily conotoxin that is able to block sodium channels.
一种名为lt6c的新型芋螺毒素，属于O超家族芋螺毒素，是从织锦芋螺毒管的cDNA文库中鉴定出来的。全长cDNA包含一个开放阅读框，编码一个预测的22个残基的信号肽、一个22个残基的前体区域和一个由28个氨基酸组成的成熟肽。lt6c的信号肽序列在O超家族芋螺毒素中高度保守，成熟肽由六个半胱氨酸组成，排列方式为C-C-CC-C-C，这是O超家族芋螺毒素的定义模式。与硫氧还蛋白、6-组氨酸标签和凝血因子Xa切割位点融合的成熟肽在大肠杆菌中成功表达。从1升培养物中纯化出约12毫克lt6c。在全细胞膜片钳模式下，lt6c抑制成年大鼠背根神经节神经元上的钠电流。因此，lt6c是一种能够阻断钠通道的新型O超家族芋螺毒素。
