hIL-15-SA双功能融合蛋白的制备

目的：对双功能融合蛋白hIL-15-SA的发酵及纯化工艺进行研究。方法：采用发酵罐高密度发酵hIL-15-SA工程菌,通过镍柱亲和层析及阴离子交换层析纯化目的蛋白。免疫印迹分析产物,淋巴细胞增殖试验以及细胞锚定试验检测双功能融合蛋白hIL-15-SA的生物学活性。结果：采用半合成培养基,以3%的接种量,pH值为7.2发酵可得到湿菌47 g/L,21.15 g/L包涵体。经纯化后目的蛋白纯度为97%。细胞增殖试验和细胞表面锚定修饰试验表明,经纯化复性的hIL-15-SA融合蛋白具有双重生物活性。结论：本研究获得了高产量、高纯度的hIL-15-SA双功能融合蛋白,为后续的体内生物学功能研究奠定了基础。

Preparation of hIL-15-SA fusion protein

Objective：To study the fermentation and purification of bifunctional fusion protein hIL-15-SA.Methods：The target protein was orified through the application of affinity chromatography and anion exchange chromatography using high-density fermentation of hIL-15-SA from E.coli.Immunoblotting analysis was used to analyze the hIL-15-SA.Lymphocyte cell proliferation assay and cell-surface-modification assay were performed to analyze the bi-functionalities of the fusion protein.Results：Using the semi synthetic mediumt,he optimal inoculum size was 3% and pH value was 7.0,47 g/L wet cells and 21.15 g/L inclusion bodies were collected.The purity of target protein reached 97% after purification.Cell proliferation and cell-surface-modification assays demonstrated that the purified and refolded hIL-15-SA fusion protein retained both hIL-15 and streptavidin bioactivities.Conclusion：The work presented an efficient way to prepare hIL-15-SA bifunctional fusion protein with large quantity and good purity,thus will allow us to perform further studies in vivo.