类弹性蛋白标签在重组蛋白分离纯化中的应用

Application of Elastin-like Polypeptide Tag for Recombinant Proteins Purification

类弹性蛋白(elastin-like polypeptide,ELP)是一种非常有前途的重组蛋白分离纯化标签。这种人工合成的蛋白质多肽是由五肽重复序列单元(VPGXG)串联组成,具有温度诱导的可逆相变特性。ELP与目的蛋白融合后,赋予重组蛋白相类似的可逆相变性质。多次可逆相变循环(inverse transition cycling,ITC)之后,就可以从蛋白溶液混合液中选择性地分离出ELP融合蛋白,再经特异性酶切或者改变环境条件引发内含肽发生自我剪切去除ELP标签,从而得到单一的目的蛋白,实现简单快速分离纯化重组蛋白。目前,该技术已成功应用于原核大肠杆菌和植物表达系统中。大肠杆菌表达ELP-绿色荧光融合蛋白的最高产量可达1.6g/L。这种非色谱分离纯化重组蛋白的方法具有技术简单、操作快速、成本低、易于扩大等优点。重点从该技术的原理、技术路线以及发展方向进行综述。

Elastin-like polypeptide （ ELP ） is an extremely promising recombinant protein purification tag. The artificial polypeptides consist of repeats of the pentapeptide （ VPGXG ） with a reversible phase transition at a specific temperature. ELP fusion protein retains this behavior when a target protein is fused to the ELP at the gene level. Once isolating a recombinant ELP fusion protein from the protein solution by repeating inverse transition cycling （ ITC ） , the ELP tag can be proteolytically removed, or self-cleave mediated by intein in response to solution condition shift, then we can recover the pure target protein. At present, the method is used successfully in expression systems such as E.coli and plants. The highest yield of GFP-ELP fusion protein is 1.6 g/L in E.coli. This non-chromatographic purification method is simple, rapid, cost-effective, and easy to scale up. This review summarizes mechanism, technical route and development direction of this method.