摘要
从一名丙型肝炎病人的外周血单个核细胞(PBMC)中分别克隆了前体和成熟人白细胞介素-18(hIL-18)的基因,并应用大肠杆菌表达系统(pQE-30),成功地表达了重组hIL-18的前体和成熟蛋白。从人PBMC中提取总RNA,用poly(T)8-12反转录成cDNA,再以PCR扩增出特异DNA 片段。利用E.coli表达载体pQE-30,构建分别表达hIL-18前体和成熟蛋白的的重组质粒pQEIL18p 和pQEIL18m ,转化E.coliM15后,经IPTG诱导,表达出相对分子质量分别为24KD和19KD的重组蛋白,表达量占菌体蛋白的30% 和35% 。序列测定证实,hIL-18前体蛋白基因长582bp,成熟蛋白基因长477bp。经金属螯合层析纯化,获得了高纯度的表达蛋白。生物学活性鉴定,重组成熟蛋白能显著刺激Con
The cDNAs encoding precursor and mature human interleukin 18 was amplified from total RNA of a hepatitis C virus carriers peripheral blood mononuclear cells (PBMC) by RT PCR respectively. Two recombinant plasmids pQEIL18 p and pQEIL18 m were constructed by cloning cDNA of IL 18 p and IL 18 m into pQE 30 vector.By induction of IPTG, the E.coli M15 harbouring the two kinds of constructs expressed recombinant proteins with molecular weight 24KD and 19KD, respectively. Both proteins were purified with Nickel chelate affinity chromatography. The recombinant mature IL 18 induced INF γ production of Con A stimulated PBMC.
出处
《免疫学杂志》
CAS
CSCD
北大核心
1999年第4期226-228,共3页
Immunological Journal