重组酿酒酵母表达乙肝表面抗原过程的限制性步骤

Limiting Steps of HBsAg Expression in Recombinant Saccharomyces cerevisiae Fermentation

考察了重组酿酒酵母表达乙肝表面抗原(HBsAg)的限制性步骤,发现在对数生长期的中后期,与发酵初期相比,外源质粒的拷贝数下降了40%,此后质粒拷贝数在低水平保持稳定。在发酵过程中添加乙醇胺,抗原基因启动子的转录效率下降了24%,但抗原效价上升了31%,说明HBsAg表达的主要限制步骤在抗原多肽的翻译和颗粒形成的后加工过程。

The limiting steps of HBsAg expression in recombinant Saccharomyces cerevisiae were analyzed. It was found that, in the middle/late exponential phase, the plasmid copy number usually decreased by 40% compared with that at the beginning of fermentation, and then kept relatively stable in a low level. With the supplementation of ethanolamine, the transcription efficiency of HBsAg gene decreased but the antigen unit expressed was improved. These meant that the major limiting steps in the recombinant HBsAg expression were translation and posttranslation processing.