重组降血压肽在大肠杆菌中的高效表达

目的利用基因工程技术在大肠杆菌中高效表达降血压肽,为大规模生产降血压肽奠定基础。方法分析降血压肽结构和功能之间的关系,人工合成具有较高活性的降血压肽基因序列,并进一步串联融合为6拷贝降血压肽,克隆至表达载体pGEX-4T-2上并转化宿主菌BL21中,重组菌经诱导培养、亲和色谱以及凝血酶酶切分离纯化得降血压肽。结果融合蛋白质的表达量为1.1 g/L,纯化得到的目的降血压肽含量达0.14 g/L,抑制活性达到85%。结论串联的6拷贝降血压七肽可在大肠杆菌中高效表达。

High-level expression of recombinant angiotensin-converting enzyme inhibitory peptide in E.coli

PurposeTo produce angiotensin-converting enzyme inhibitory peptides(ACEIP) on a large scale,express ACEIP in E.coil by gene technology.MethodsBased on the relationship between bioactivity and molecular structure of the ACEIP,the six same peptides were jointed by specific enzyme cleavage site to construct a multi-copy peptide.The corresponding coding gene was synthesized by using favored condons of E.coli,and cloned into the plasmid pGEX-4T-2,and then transformed into E.coli BL21.After the induced culture,the recombinant fusion protein expressed by this positive strain was analyzed and purified with Glutathione Seoharose 4B column,hydrolyzed with thrombin and purified by HiTrap Benzamidine FF.ResultsThe expression level of soluble GST-ACEIP was about 1.1 g/L,and the target peptide was about 0.14 g/L.The inhibitory rate of ACE of the final target peptide was 85%.ConclusionThe fusion ACEIP can express in E coil BL21.