目的PTD-SOD是含有PTD和SOD的融合蛋白,前人的研究表明它能跨膜进入细胞,具有比SOD更高的生物利用率。但至今为止的表达都是在大肠杆菌中完成的,得到的是没有活性的包涵体。本文将人工合成的PTD-SOD全基因插入含有AOX1基因启动子和分泌信号肽序列的毕赤酵母表达载体pPICZα中,重组载体转化进入毕赤酵母。结果表明,经甲醇诱导,配合蛋白PTD-SOD成功得到分泌表达,表达量随诱导时间的延长而递增,诱导8d后活力达到最高,值为301.48U·mL^-1。由于本文构建的毕赤酵母表达系统表达的PTD-SOD是有活性的分泌蛋白,这就为下游的工艺操作带来了极大的便利,为PTD-SOD的理化研究和工业化生产提供了物质基础。
OBJECTIVE PTD-SOD is the fusion protein of PTD and SOD. Previous reports showed that it had the ability to tranverse the cell membranes and had higher bioavailability than SOD. However, the expression up to now is still in E. coli in the form of inclusion bodies without any enzyme activity. Therefore, the coding sequence of was inserted PTD-SOD into yeast expression vector pPICZα containing AOXI promoter and α-factor signal peptide sequence,and then the recombinant vector was transformed into. P. pastoris. It was found that the fusion protein was successfully expressed in the form of secretion protein by P. pastoris inducted with methanol induction the expression level increased with prolongation of induction time. After 8 days of methanol induction, the expressed PTD-SOD reached the peak of 301,48U - mL-J. As PTD-SOD expressed in Pichia system is a kind of secretion protein,it brings great convenience for the downstream technology of recombinant protein. Therefore, this paper provided basis theoretic research and industrial production of PTD-SOD.