一种白细胞介素2基因变构体的高效表达与纯化工艺

利用定点诱变技术构建表达质粒pET15b-MhIL-2并将其在大肠杆菌中进行表达发酵的优化研究，高效表达出可溶性的MhIL-2重组蛋白。蛋白经过亲和层析、Thrombin酶切、离子交换层析和凝胶过滤层析纯化，MhIL-2纯度达95%，且MhIL-2比hIL-2具有更强的促进T细胞增殖生物活性。

Efficient Expression and Purification Technique of a Mutant of Human Interleukin 2

Mutants of recombinant hIL-2 (rhIL-2), generated by using site-directed mutagenesis strategy, can increase anti-tumor activity and decrease toxicity. We have used site-directed mutagenesis of hIL-2 to generate a mutant of hIL-2(MhIL-2) in which Asn88 was substituted by Arg88. To reduce the undesirable formation of inclusion body and maximize the yield of soluble MhIL-2 fusion protein, we adapted a protocol for the expression of soluble MhIL-2 fusion protein. Our results have indicated that soluble form of the MhIL-2 fusion protein is expressed from E. coli.. Moreover, it also has facilitated purification of the MhIL-2. SDS-PAGE analysis revealed that the MhIL-2 protein was efficiently purified to 95% purity by the combination of nickel ion Chelating column chromatography, Desalting column chromatography, thrombin cleavage and Superdex 75 gel filtration column chromatography. Proliferation assay of T lymphocyte of purified MhIL-2 showed that the biological activity of MhIL-2 was higher than that of standard hIL-2 in vitro. This work not only describes an efficient preparation strategy of MhIL-2, but also introduces a highly active MhIL-2 that may have important clinical applicability.