重组胸腺肽α1在大肠杆菌中的表达与免疫活性检测

根据大肠杆菌密码子偏嗜性修改、合成胸腺肽alpha 1（Tα1）基因并连接到pET32α（＋）中构建融合表达载体pET32α-Tα1,转化大肠杆菌BL21（DE3）,IPTG诱导,经15%SDS-PAGE检测,Tα1获得可溶性表达。将诱导表达菌高压均质破碎后进行亲和层析纯化,洗脱蛋白峰经脱盐处理后进行免疫活性测定。通过脾淋巴细胞转化试验测定纯化重组Tα1和人用Tα1的活性,结果显示,重组表达的Tα1具有明显的促进淋巴细胞增殖的活性;脱E受体法E玫瑰花环试验测定结果显示,制备的重组Tα1的E玫瑰花结百分率高于空白对照组14.3%以上（胸腺肽溶液的质量标准为提高10%）,能够明显增强T细胞的活性。

The expression of recombinant thymosin alpha 1 in E.coli and its biological function

According to Escherichia coli codon preference,synthesize thymosin alpha 1（Tα1） gene and attach to vector pET32α（＋）,convert Escherichia coli BL21（DE3）.After IPTG induction,by 15% SDS-PAGE detected,Tα1 obtain soluble expression.A positive fusion protein band,which matches protein molecular weight about 21 800,was detected in the expression product.Then the expressed recombinant Tα1 was purified by Ni2＋ affinity chromatography,and test samples was prepared by the desalination after eluting protein peaks was collected.The immune activity of purified recombinant Tα1 was detected by lymphocyte transformation test and E rosette test.The results showed that recombinant fusion Tα1 could obviously promote BALB/c mice spleen lymphocyte proliferation.The E rosette percentage of purified recombinant Tα1 was higher 14.3% than the control group,being higher than the quality standards of thymosin solution（not less than 10% of the percentage of E rosette）,indicating could significantly enhance the activity of T cells.These results suggest that recombinant Tα1 have a similar immunological activity in vitro,compared with the synthetic or natural Tα1.