用ＰＣＲ法获得了ＨＢｓＡｇｐｒｅＳ１（１－６５）肽段基因，将该基因融合在肿瘤坏死因子（ｈＴＮＦα）之后，插入表达载体ＰＳＢ－９２中，使融合基因的５′端直接置于大肠肝菌ＰＬ启动子下游，采用３０℃培养，４２℃诱导，获得了ＴＮＦ与ｐｒｅＳ１（１－６５）融合蛋白的表达产物。ＳＤＳ－ＰＡＧＥ电泳显示表达产物为２５ｋＤ，约占细菌总蛋白的３５％。表达产物经Ｗｅｓｔｅｒｎｂｌｏｔ验证，能分别特异地与ｈＴＮＦα抗体与ｐｒｅＳ１抗体结合，稀释复性后，该融合蛋白还具有ＴＮＦ的生理功能（对Ｌ９２９细胞的细胞毒活性）。经ＤＮＡ序列测定，ｐｒｅＳ１（１－６５）肽基因正确地融合在ｈＴＮＦα基因之后。该结果提供了一种制备ｐｒｅＳ１的新方法，为进一步开展治疗肝癌和乙肝的导向药物打下基础。

The gene encoding the N terminal 1-65 amino acids of preS1 was amplified by PCR and fused to the 3′ end of hTNF α gene to form a hTNF α preS1 fused gene which was directly inserted into the expression vector pSB 92 between EcoRⅠ and BamHⅠ sites and under the control of P 1 promoter. The fused hTNF α preS1(1-65) gene can be expressed in E.coli by temperature induction. The expression level was up to more than 35% and expressed fussion protein was shown by a major band with a expected molecular weight about 25kD on SDS PAGE, and also confirmed by Western blot analysis with anti hTNFα monoclonal antibody and anti preS1 monoclonal antibody. After renaturation, the fused protien displayed the hTNFα biological activity. The preS1(1-65) gene is found to be accurately fused to hTNFα by sequence analysis.