人α_2b型干扰素的基因克隆及其在大肠杆菌中的表达提高

GENE CLONING AND INCREASING EXPRESSION OF HU-IFN-α_2b IN E.coli

应用ＰＣＲ的方法，从人的染色体片段制备人α_２ｂ干扰素的ｃＤＮＡ，将其克隆到ｐＲＣ_（２３）表达载体上，构建成重组表达质粒ｐＭＺＩ_２Ａ和ｐＭＺＩ_２Ｂ，并转化大肠杆菌ＤＨ_（５α）组建成工程菌。ｐＭＺＩ_２Ａ和ｐＭＺＩ_２Ｂ的区别在于后者的α_２ｂ基因５＇－端起始密码ＡＴＧ上游编制了一段ＳＤ顺序，与ｐＬ启动子上连接的ＳＤ顺序组成双ＳＤ顺序。表达重组质粒中由于不含ｃＩｔＳ基因，所以采取３７℃连续培养后比较两者的抗病毒活性，表明ｐＭＺＩ_２Ｂ的表达比ｐＭＺＩ_２Ａ有明显的提高，分别为１．６９×１０￣４ＩＵ／ｍｌ和３．４６×１０￣３ＩＵ／ｍｌ。

The expression plasmids of recombinant Hu-IFN-α_2b,pMZI_2A and pMZI_2B were constructed,and expressed under the control of pL promoter in E.coli.pMZI_2B is different from pMZI_2A on upstream of ATG codon. Two SD sequences were weaved in pMZI_2B. cItS gene was not contained in two recombinant plasmids.After culture the anti-virus activity of pMZI_2B (1.69×10￣4 IU/ml)was higher than pMZI_2A(3.46× 10￣3IU/ml).