人组织因子途径抑制因子在毕赤酵母中高拷贝表达

目的 构建高拷贝表达重组人组织因子途径抑制因子的毕赤酵母并对蛋白表达条件进行初步优化,为相关研究奠定基础.方法 将PCR扩增得到的TFPI cDNA片段与表达质粒pPIC9K连接构建重组质粒rhTFPI-pPIC9K,采用PCR方法及DNA测序对其进行鉴定.将重组质粒转化酵母细胞GS115,利用G418抗性实验筛选含有...

High-copy expression of tissue factor pathway inhibitor in pichia pastoris

Objective To generate recombinant Pichia pastoris for high-copy expression of human tissue factor pathway inhibitor (TFPI). Methods The cDNA encoding human TFPI was inserted into the expression vector pPIC9K and the constructed expression vector rhTFPI-pPIC9K was confirmed by restriction endonuclease analysis and DNA sequencing. The recombinant plasmids were subsequently transformed into Pichia pastoris GS115 cells, and the transformants were confirmed by PCR amplification of the genomic DNA.The recombinant Pichia pastoris with high copies of TFPI cDNA was screened by G418 selection. Western blot and TFPI ELISA Kit were employed to analyzing. The temperature, time and concentration of methanol for the induction of recombinant protein were optimized. Results PCR analysis and DNA sequencing confirmed the successful construction of the expression vector rhTFPI-pPIC9K. Real time quantitative PCR and Western blot analysis demonstrated the positive correlation between TFPI expression level and the copy number of TFPI cDNA in Pichia pastoris cells. Optimization of the induction condition significantly elevated the expression level and activity of TFPI (9.95±0.78 mg/L and 3.91±1.37 U/mL). Conclusion The Pichia pastoris strain with high copy of TFPI expression was successfully constructed, which lays a solid foundation for the further investigation on the function of TFPI and its application in the prevention and therapy of diseases.