Periplasmic expression of recombinant proteins ensures the production of biologically active proteins in a correctly folded state with several key advantages. This research focused on the in-frame cloning of rhIL-15 in pET-20 (+) vector with pelB-leader sequence to direct the protein to the bacterial periplasm. The target construct periplasmic expression was evaluated in four strains, BL21 (DE3), BL21 (DE3) pLysS, Rosetta 2 (DE3) and Rosetta-gami 2 (DE3). Soluble periplasmic expression of IL-15 was highest in Rosetta-gami 2 (DE3) followed by Rossetta 2 (DE3) whereas negligible expression was observed with rest of two expression host. Best expression clone was selected for purification by dye ligand affinity chromatography. Purified rhIL-15 was characterized by SDS-PAGE, Western blotting and SEC-HPLC. This is the first report of functional recombinant human interleukin-15 being expressed and purified with yield of 120 mg/L in the periplasmic space of E. coli.

重组蛋白的周质表达确保了正确折叠状态的生物活性蛋白的生产，具有几个关键优势。这项研究的重点是利用pelB-leader序列将pET-20（+）载体中的rhIL-15进行框内克隆，以将蛋白质引导至细菌周质。在四种菌株BL21（DE3），BL21（DE3）pLysS，Rosetta 2（DE3）和Rosetta-gami 2（DE3）中评估了靶构建体的质粒表达。IL-15的可溶性周质表达在Rosetta-gami 2（DE3）中最高，其次是Rossetta 2（DE3），而在其余两个表达宿主中观察到的表达可忽略不计。选择最佳表达克隆用于通过染料配体亲和层析纯化。通过SDS-PAGE，蛋白质印迹和SEC-HPLC对纯化的rhIL-15进行表征。大肠杆菌。