文章摘要
赵志文 张峥 刘浩文 黄智刚 吴颖.不同标签辅助的IBTX原核表达纯化及活性鉴定[J].,2014,14(7):1207-1211
不同标签辅助的IBTX原核表达纯化及活性鉴定
The Expression, Purification and Identification of IBTX inwith Different Tags
  
DOI:
中文关键词: 钾离子通道毒素  IBTX  标签蛋白  BK
英文关键词: KTX  IBTX  Protein tags  BK
基金项目:国家重点基础发展规划项目(973 子项目)(2010CB529804)
作者单位
赵志文 张峥 刘浩文 黄智刚 吴颖 华中科技大学生命科学与技术学院 
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中文摘要:
      目的:在原核体系中建立高效表达纯化IBTX(Iberiotoxin)的工艺,并比较不同标签对IBTX生物活性的影响。方法:利用引 物搭桥的方法,经PCR 扩增,获得IBTX 编码基因,以此为模板分别构建了表达质粒PET32a(+)-IBTX、pGex-6p-1-IBTX、 pDuet-MBP-IBTX,并将其转入E.coli(BL21)分别表达带有硫氧还原蛋白(TRX)、谷胱甘肽巯基转移酶(GST)、麦芽糖结合蛋白 (MBP)标签的IBTX 融合蛋白,在经过亲和层析、烟草蚀纹病毒(TEV)蛋白酶酶切、C18 反向层析纯化后真空冻干得到IBTX干粉, 以电生理实验检测其生物活性。结果:在三种标签帮助下通过原核体系表达出的IBTX 都能够特异性的阻断大电导Ca2+激活的 钾通道(BK)电流,其中MBP帮助折叠的m-IBTX 活性最佳。结论:建立了IBTX 在MBP 标签帮助下的原核表达纯化工艺,为进 一步研究蝎钾离子通道alha家族神经毒素及其突变体的原核表达奠定了基础。
英文摘要:
      Objective:To establish the process of expressing and purifing the effective IBTX in E.coli, and compare the impact of different protein tags on the bioactivity of the recombinant IBTX.Methods: The overlapping polymerase chain reaction (PCR) was used, and the IBTX coding sequence was cloned into PET32a (+), pGex-6p-1 and pDuet-MBP vectors. The plasimid PET32a (+)-IBTX, pGex-6p-1-IBTX and pDuet-MBP-IBTX were transformed into E.coli BL21 for the expression of IBTX fusion proteins. After the process of affinity chromatography, protein cleavage by TEV and reversed phase chromatography by a semi-preparative C18 column, the IBTX was lyophilized into powder and tested by the electrophysiological experiments.Results:All the IBTXs folded with the exsistence of the three tags in E.coli could specially block the BK channel, and the IBTX folded by MBP (m-IBTX) showed the greatest acitvity.Conclusion:The process of IBTX expression and purification with the help of MBP in has been well established, which provides a reference for the further research about getting the alpha-KTx family memebers and their variants in prokaryotic system.
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