两水相萃取法从重组大肠杆菌匀浆液中提取干扰素α1的研究

Study on the Extraction of Interferon α1 from Recombinant Escherichia coli Homogenate by Aqueous Two-phase Partitioning

本文以PEG磷酸酯/磷酸盐两水相系统,经两次萃取从重组大肠杆菌匀浆液中提取干扰素a_1。最适萃取条件为22%PEG磷酸酯,16%磷酸盐,3%NaCI,pri6.9。IFNa_1的分配系数达到155,收率99.6%,纯度提高25倍,对反萃取条件作了初步研究,较好的条件为20%PEG磷酸酯,10%磷酸盐,pH6.0,收率达到75.6%,但浓度有所稀释。与传统的提取方法相比,本法可省去高速离心去除细胞碎片的步骤,操作简单,能耗较低,而且收率较高,纯度电有所提高,最后IFNa_1存在于磷酸盐相中,其中PEG含员仅为0.5%左右,这对后继纯化操作很有利。

In this paper,aqueous two-phase system composed of PEG-phosphate ester/phosphate was used twice to isolate IFNα_1 from recombinant E. coli homogenate. The optimum extraction conditions were: 22% PEG-phosphate ester, 16% phosphate and 3% NaCl at pH6.9. The partition coefficient of K_(IFN) was as high as 155 with a yield of 99.6% and 25 folds increase of purity. Preliminary study on back-extraction showed 20% PEG-phosphate ester/10% phosphate system at pH6.0 was suitable with 75.6% yield and IFN concentration diluted by a factor of 4, however. In comparison with the conventional method the removal of cell debris by high-speed centrifugation was no longer needed. This would ease operation and lower energy consumption. In addition, the yield was much higher and purity somewhat higher. Finally, IFNα_1 was transfered to the phosphate phase with no more than 0.5% PEG which will facilitate the subsequent purification step.