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通过兼并引物PCR结合RACE技术,克隆了棉铃虫Helicoverpa armigera(Hbner)保幼激素环氧水解酶(juven-ile hormone epoxide hydrolase,JHEH)的基因,该基因的开放阅读框为1389bp,编码463个氨基酸。预测蛋白分子量为52kD,等电点为6.39。N末端存在由20个氨基酸组成的疏水性信号肽序列,存在组成JHEH催化三联体的氨基酸Asp(227)、Glu(403)和His(430)以及组成阴氧离子洞的氨基酸Tyr(298)、Tyr(373)和HGWP花样结构。其氨基酸序列与其它鳞翅目昆虫有很高的同源性。在大肠杆菌中表达JHEH基因的编码区,Western blot结果表明,棉铃虫JHEH已被成功表达。利用该基因序列可以在分子水平上研究棉铃虫JHEH基因的时空表达情况,进一步研究保幼激素(juvenile hormone,JH)的代谢途径及其功能。
The gene of juvenile hormone epoxide hydrolase (JHEH) of Helicoverpa armigera (Hbner) was cloned by PCR and RACE technique. The open reading frame of this gene was 1389bp and encoding 463 Amino acids. The predicted molecular weight was 52kD and the isoelectric point was 6.39. There is a hydrophobic signal peptide sequence consisting of 20 amino acids at the N terminus. The amino acids Asp (227), Glu (403) and His (430) which make up the JHEH catalytic triad and the amino acid Tyr (298) Tyr (373) and HGWP pattern structures. Its amino acid sequence and other Lepidoptera have very high homology. The coding region of JHEH gene was expressed in Escherichia coli. Western blot showed that the JHEH of Helicoverpa armigera was successfully expressed. Using this gene sequence, the temporal and spatial expression of JHEH gene in Helicoverpa armigera could be studied at molecular level to further study the metabolic pathway and function of juvenile hormone (JH).