E.coli HB101(pBV-IL-6)的流加分批培养及其产物纯化

The Fed Batch Cultivation of E.coli HB101(pBV-IL-6) and the Purification of Product

E.coli HB101(pBV-IL-6)工程菌株的表达产物为N端缺失25个氨基酸残基的IL-6衍生物。通过摇瓶试验选定了培养基配方及pH值的控制范围,在5L发酵罐的半连续培养中确定了培养和诱导时间。在此基础上放大到30L发酵罐进行培养,结果表明,菌密度达到5.15g/L(干重),rIL-6衍生物占菌体总蛋白的34.8％。表达产物经过纯化和复性,纯度达95％以上(SDS-PAGE分析),采用依赖IL-6的小鼠杂交瘤细胞株7TD-1和~3H-TdR掺入法测定生物活性,rIL-6衍生物比活性为7.71×10~6U/mg。

The derivative of interleukin-6 which deflated 25 ammo acid residues at N-termmus was produced from genetic engineering bacteria. The composition of the medium and the range of pH were investigated by the cultivation of flasks. The time of cultivation and induction were determined by the fed batch cultivation in 5L fermentor. When the fermentation was carried out under the determined conditions in 30L fermentor, the density of cell was 5. ! 5 g/ L (dry weight) the derivative of recombiant interleukin-6 in the total protion of the cell was 34. 8%. The purity of product was above 95% after renaturation and purification. The method of H-l dR incorporation into an IL-6-de-pendent mouse-mouse hybrid cell 7TD1 was utilized to determine the activity of IL-6. The specific activity of the derivative of IL-6 was 7. 17X 106 U/mg (protein).