一种αⅠ型干扰素基因新变种的发现和鉴定

本文从一名中国汉族正常人胎肝细胞染色体DNA中,应用PCR方法两次获得长为520 bp的人α型干扰素基因,核苷酸序列测定表明,两次扩增产物的DNA序列完全相同,与过去分离克隆的IFN-αI和IFN-αD基因相比较,其第410位和第541位核苷酸分别为C和G,由此推测它编码的IFN成熟肽第114位和第158位氨基酸应为Ala和Val,其余位点则与IFN-αD和IFN-αI完全相同.我们建议将IFN—αD,IFN—αI和我们分离的IFN-αI/158V基因分别命名为IFN-αIa,IFN-αIb和IFN-alc基因.     

Cloning, Sequencing and Expression in E. coli of Interferon-ω1 Gene

Human interferon ω1 (huIFN-ω1) gene was isolated and cloned from chromosome DNA derived from a Chinese fetal liver via polymerase chain reaction (PCR). By determining its nucleotide sequence we proved that the 88th codon should be GGA, coding for Gly. After engineering the original IFN-ω1 gene clone to a form that may be expressed as a nonfused protein, we also took the IFN-ω1 gene under the control of the PRPL promoter with an expression vector pBV220 in E. coli. The antivirus activity of the recombinant IFN-ω1 is about 6.5×10~7 units/L CULTURE (OD_(600)=0.75). Since IFN-ω1 not only has antivirus activity but also shows considerably high homology with animal trophoblast proteins which have been proved antiluteolysins as a maternal recognition signal for pregnancy, we believe that study on it will be practically and theoretically significant.     

中国人ω1型干扰素基因的克隆、一级结构测定以及在大肠杆菌中的表达

采用聚合酶链反应(PCR)方法,从中国正常胎儿肝细胞染色体DNA中分离并克隆了人ω1型干扰素基因,测定了核苷酸全序列,表明原有争议的第88位密码子为GGA的核苷酸序列是正确的,因此该氨基酸为Gly。随后又利用PCR技术将所获的ω1型干扰素基因原始克隆改造成适于在大肠杆菌中表达非融合蛋白的结构形式,并以pBV220为载体在P_RP_L串联启动子控制下进行温控表达。表达产物的抗病毒活性达6.5×10~7单位/升菌液(O. D_600=0.75)。IFN-ω1不仅具有很高的抗病毒活性,同时在结构上与动物滋养层蛋白高度相似,而后者又是作为母体妊娠识别信号存在于多种动物体内的抗黄体退化蛋白,因此本文获得的这—ω1型干扰素基因及重组蛋白在理论和实际上都有进一步研究的价值。     

A NOVEL VARIANT OF HUMAN INTERFERON α1 GENE

A 520-base pair human IFN-α gene was isolated by PCR method twice from chromosome DNA of a Chinese (Han Nationality) fetal liver. The nucleotide sequences were determined. These two separately amplified DNA fragments shared the completely identical nucleotide sequence but possessed C and G at positions 410 and 541, respectively, which differ from those oflFN-α1 and IFN-αD previously described. Therefore the deduced amino acid sequence would have an Ala at position 114 and a Val at position 158. At all other sites it has the same amino acids as those in IFN-α1 and IFN-αD. We recommend that IFN-αD gene, IFN-αI gene and IFN-αI/158V gene found in our laboratory, be named IFN-αla gene, IFN-αlb gene and IFN-αlc gene.     

脑啡肽-干扰素融合蛋白具有较高的抑制肿瘤细胞生长活性

本文根据有些肿瘤细胞表面富含δ型阿片受体的事实,化学合成了脑啡肽(Enk)N端5肽编码区,将其通过一连接3肽编码区与人α1型干扰素(IFN)基因相连,并在大肠杆菌中表达了这一融合蛋白。以体外培养的人结肠腺癌细胞和多形胶质瘤细胞为模型,采用~3H_1胸腺嘧啶核苷掺入法证明该融合蛋白抑制肿瘤细胞生长的活性显著高于单纯的IFN分子。通过Naloxone竞争阻断试验证明,这种抑制活性的增高确由Enk导向区介导。本文报道为IFN作用机制的研究提出了新课题,同时也展示了导向IFN治疗肿瘤的应用前景。