The Changes of Rare Cordons Increase Expression Level of SEA
改造稀有密码子提高SEA蛋白表达量

The rare codons of a fragment in staphylococcal enterotoxin A gene were turned into the most high usage frequency codons in E.coli by overlap PCR technique. Genes of sea and sea m were cloned into 7ZTS expression vector and transformed into JM109(DE3),respectively. The result shows that expression level of sea gene was very low, but the expression level of sea m was as high as 15% of total cell proteins. The expression product shows activity of antitumor in vivo .