恶性疟原虫杂合多肽抗原融合基因的克隆和表达

Cloning and Expression of Complex Antigen Fusion Genes of Plasmodium falciparum

合成了５对寡核苷酸片段，分别连接在两种恶性疟原虫杂合多肽（４５肽和５８肽）抗原基因片段（ＨＰＦＧＡ和ＨＰＦＧＢ）的头部和尾部，将这两种片段分别与霍乱毒素Ｂ亚单位（ＣＴ－Ｂ）基因末端融合。两种杂合多肽抗原分别含有数个红内期和红外期有代表性的、并能被Ｔ或Ｂ淋巴细胞识别的保护性抗原表位，ＣＴ－Ｂ基因前端具有促使分泌的信号肽序列。将这两种融合基因的不同重组质粒分别转化大肠杆菌，对转化菌的培养上清检测表明融合蛋白被分泌性表达，既具有恶性疟原虫和ＣＴ－Ｂ抗原性，又保持了ＣＴ－Ｂ与其受体神经节苷脂ＣＭ１结合的生物学活性。

Five pairs of chemically synthesized complementary oligonucleotides were linked differently to both ends of two chemically synthesized gene fragments of comlex antigens which contained representative protective epitopes of exo-erythrocytic and erythrocytic stages of Plasmodium falciparum. Then the two reconstructed complex antigen gene fragments were respectively cloned and fused in correct open reading frame with cholera toxin B subunit(CT-B) gene preceded by a signal peptide sequence. After the new recombinant plasmids were transformed into E.coli,the fusion proteins could be specifically expressed.secreted to the medium and also preserved the biological activity of CT-B that binding with its receptor GM1.