中国人α1型干扰素基因新变种的cDNA序列测定及其表达

Sequencing of One Novel Variant of Human Interferon α1 Gene in China and Its Expression

为了逐步阐明中国人ＩＦＮ－α基因结构与功能的特点，将从一中国汉族正常胎儿肝细胞染色体ＤＮＡ中获得的一组ＰＣＲ克隆产物（ＰＣＲＡ０１、ＰＣＲＡ０２）分别进行核苷酸序列测定。结果表明，以上两次ＰＣＲ产物序列完全相同，它们与过去分离的ＩＦＮ－α１和ＩＦＮ－αＤ基因之间的氨基酸序列差异小于１％，为ＩＦＮ－α１基因的不同变种。ＰＣＲＡ０１、ＰＣＲＡ０２开放读码框架完全相同，与ＩＦＮ－α１和ＩＦＮ－αＤ基因相比较，其第２９９位为Ｔ，与其相应编码的第１００位氨基酸为Ｖａｌ。该基因为继黎孟枫等１９９１年所分离的ＩＦＮ－α１Ｃ基因之后所发现的又一中国人α１型干扰素基因新变种——ＩＦＮ－α１／１００Ｖ，建议命名为ＩＦＮ－α１ｄ基因。将该基因克隆于原核表达载体ＰＢＶ２２０，测定其抗病毒活性为２．４×１０７Ｕ／Ｌ。

In order to elucidate the structure and function character of Chinese interferon α(IFN α) gene, the nucleotide sequences of one group of PCR cloning products PCRA01, PCRA02 which were separated from chromosome DNA of Chinese (Han nationality) fetal liver, were detected. The sequences of PCRA01 and PCRA02 were completely identical, and their differences of amino acid sequence between IFN α1 and IFN αD gene were less than 1 %, suggesting that they were probably one allelic variant of IFN α1 gene. PCRA01 and PCRA02 differed from IFN α1 and IFN αD by change in their coding regions at nucleotide position 299, thus position 100 of the amino acid sequence would be Val. It revealed that the gene we cloned was another novel variant of IFN α1 gene-IFN α1/100V after IFN α 1C gene reported by Li Mengfeng in 1991. It was proposed that IFN-α 1/100V gene was named IFN α1d gene. In addition, the anti viral activity of IFN α1/100 V was 2.4×10 7 U/L when the gene expressed in prokaryotic expression vector PBV220.