摘要
目的 获得人胰腺α-淀粉酶(AMY2A)基因并进行原核表达。方法 采用基因工程技术,根据人AMY2A基因序列设计并合成特异性引物;从人胰腺组织中提取总RNA,反转录成CDNA第一链;逆转录-聚合酶链反应(RT-PCR)扩增人胰腺AMY2A基因,经BamH Ⅰ和Kpn Ⅰ双酶切、连接并插入原核表达载体pGEX-5T,构建pGEX-5T-AMY2A重组表达载体,在大肠杆菌BL21中异丙基硫代半乳糖苷酶(IPTG)诱导表达AMY2A蛋白。包涵体经尿素变性、复性及谷胱苷肽琼脂糖柱亲和层析纯化、AMY2A酶活性测定和免疫印迹分析。结果 重组质粒测序和酶切结果显示AMY2A基因已正确插入pGEX-5T,重组蛋白、复性及纯化产物SDS聚丙烯酰胺凝胶电泳(SDS-PAGE)在84 000处有一条明显的蛋白表达条带,AMY2A检测具有酶活性,免疫印迹分析表明重组蛋白具有人胰腺淀粉酶抗原性。结论 作者已克隆并在大肠杆菌中初步表达并获得纯化的谷胱苷肽转移酶(GST)-AMY2A融合蛋白。
Objective To obtain recombinant human pancreatic alpha-amylase protein (AMY2A). Methods Human pancreatic AMY2A cDNA was synthesized by RT-PCR using total RNA from human pancreatic tissues and a couple of primers designed according to the know sequence of human pancreatic alpha-amy lase gene, then digested with BamH Ⅰ and Kpn Ⅰ and inserted into the prokaryotic expression plasmid pGEX-5T vector. Construct The prokaryotic expression vector pGEX-5T-AMY2A was constructed and transformed into E. coli BL21 cell . Protein expressed under the induction of IPTG. The inclusion bodies were isolated and solubilized with urea and washed denatured and refolded. The fusion protein wes purified by affinity chrom atography with glutathione agarose. Results Sequence and restrction analysis revealed AMY2A gene was cloned in frame into pGEX-5T, SDS-PAGE profile showed a clear protein band with a relative molecular weight of 84000 and western blot indicated that the expressed product specifically reacted to polyclonal anti -human pancreatic AMY2A genes. Conclusion Human pancreatic AMY2A gene was successfully cloned,expressed and purification.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2004年第7期452-455,共4页
Chinese Journal of Laboratory Medicine
