人胰岛素样生长因子I基因的半合成及其克隆表达

将人胰岛素样生长因子 Ⅰ（ＩＧＦ－ Ｉ）基因克隆到 ｐＥＴ１１Ｃ中，构建成 ｐＥＴＩＧＦ－ Ｉ表达载体，完成人ＩＧＦ－Ｉ基因在大肠杆菌中的高表达。方法：利用固相亚磷酸三酯法化学合成人ＩＧＦ－Ｉ基因的２条寡核苷酸片段，通过互补配对和Ｋｌｅｎｏｗ酶促补平成完整的ＩＧＦ－Ｉ双链ＤＮＡ片段，然后经酶切克隆于ｐＴＶ１１８Ｎ载体中，构建ｐＴＶＩＧＦ－Ｉ克隆载体并测定ＤＮＡ序列后，构建ＰＥＴＩＧＦ－Ｉ表达载体。结果：合成的人ＩＧＦ－Ｉ基因经测序证明与设计的一致，人 ＩＧＦ－ Ｉ基因在大肠杆菌中表达量高于 １０％。结论：选用大肠杆菌偏性密码子，小分子的人 ＩＧＦ－ Ｉ在大肠杆菌中可实现高表达

The Semisynthesis of a Gene Encoding hIGF- I and Its Cloning and Expression in E. coli

Purpose: The gene of human insulin-like growth factor I (IGF- I ) was cloned to vectot pET11C and expression vector pETIGF- I was constructed. IGF- I was over expressed in E. coli after selection of induced condition. Methods: Two oligonucleotides of human IGF-I DNA were synthesized by means of the solid-phase phospho-triester method. The double- stranded DNA fragment of IGF- I was obtained by way of base complementarity and polymerization, the gene was then inserted into a plasmid vector pTV118N after appropriate cleavage with restriction endonuclease. The recombinant plasmid pETIGF- I was constructed after DNA sequencing and the objective gene cloning to pET11C. Results: The sequence of synthesized gene of human IGF- I was the same as that of the designed one. The expressed clever of human IGF- I gene was more than 10% in E. coli. Conclusion: Human IGF- I of low molecular weight was over expressed in E. coli after choosing the partial coden of E. coli.