替换稀有密码子提高HBsAg在CHO细胞中的表达量

目的　通过替换S基因稀有密码子 ,提高HBsAg在CHO细胞中的表达量。方法　利用重叠PCR技术 ,将S基因上 3个稀有密码子替换成哺乳动物细胞偏爱的密码子 ,得到Sm 基因。把S和Sm 基因分别克隆到pCI载体上 ,并转染CHO(dhfr )细胞 ,利用ELISA方法检测HBsAg的表达量。结果　获得预期的Sm 基因。在CHO细胞中 ,Sm 基因表达量明显高于S基因。结论　替换S基因稀有密码子可以提高HBsAg的表达量

Improvement of Expression Level of HBsAg in CHO Cells by Substitution of Rare Codons with Mammal Cell-preferred Codons

Objective To improve the expression level of HBsAg in CHO cells by the substitution of rare codons of S gene with mammal cell-preferred codons.Methods Substitute the three rare codons at S gene with three mammal cell-preferred codons by overlap PCR to obtain Sm gene.Clone S and Sm genes into pCI vector respectively and transfect to CHO(DHFR-) cells. Determine the expression level of HBsAg by its corresponding diagnostic kit.Results The expected Sm gene was obtained. The expression level of Sm gene in CHO cells was significantly higher than that of S gene.Conclusion The expression level of HBsAg was significantly improved by the substitution of rare codons with mammal cell-preferred codons.