斜纹夜蛾普通气味结合蛋白基因SlitGOBP1的克隆及序列分析

Cloning and Sequence Analysis of SlitGOBP1 Encoding a General Odorant Binding Protein 1 from Spodoptera litura

通过PCR扩增结合RACE技术克隆获得斜纹夜蛾Spodoptera litura普通气味结合蛋白1（GOBP1）基因（Slit—GOBP1）全序列．序列测定和结构分析表明，SlitGOBP1阅读框全长为495bp，编码164个氨基酸残基，预测相对分子质量和等电点分别为19270和5．29，与已报道的10种鳞翅目昆虫GOBP1相似性为90％-41％．cDNA序列GenBank登录号为EF159978．SlitGOBP1序列中有6个保守的半胱氨酸位点，具有GOBP1的典型特征．SlitGOBP1编码的蛋白呈酸性，整个分子呈亲水性，在第40-60位和100位以后的氨基酸表现亲脂性，蛋白质二级结构主要由α螺旋构成．氨基酸序列系统进化树分析表明，昆虫间GOBP1分子具有明显的保守性，SlitGOBP1与夜蛾科的烟青虫Helicoverpa assulta、烟芽夜蛾Heliothis virescerts和棉铃虫Helicoverpa armigera GOBP1属于一个分支，相似性分别为78.1％、87.6％和79.9％、这些结果为进一步了解斜纹夜蛾感受环境信息分子机制，研制昆虫行为调节剂提供了基础．

By using the total RNA isolated from the antenna of Spodoptera litura, the full-length sequence of gene encoding a general odorant binding protein 1 （named SlitGOBP1, see GenBank EF159978） was cloned by the method of reverse transcription polymerase chain reaction （RT-PCR） and rapid amplification cDNA ends （RACE）. The sequence analysis showed that SlitGOBP1 encodes 164 amino acid residues and its open reading frame was 495 bp. Deduced SlitGOBP1 protein （Mr = 19 270; pI =5.29） had six conserved cysteines. The deduced amino acid sequence showed 90% - 41% similarity to the sequence of GOBP1 from 10 species of the moth and shared several common structural features. The protein was acidic and hydrophilic, while the amino acids in 40-60 loci and the loci after 100 were hydrophobic. The protein secondary structure mainly consists of α helices. The phylogenetic tree was created from the alignments of the amino acid sequences, and the analysis revealed that GOBP1 possessed distinct conservation in evolution and SlitGOBP1 were 78. 1%, 87.6% and 79. 9% identical to GOBP1 of Helicoverpa assulta, Heliothis virescens and ttelicoverpa armigera, respectively. The results in this study would be the basis to explore the molecular mechanism of insect receiving the message from environment.