Rodríguez Sergio, Hao Guixia, Liu Weitian, Piña Benjamín, Rooney Alejandro P, Camps Francisco, Roelofs Wendell L, Fabriàs Gemma
Department of Biological Organic Chemistry, IIQAB-CSIC, IBMB-CSIC, Jordi Girona 18, 08034 Barcelona, Spain.
Insect Biochem Mol Biol. 2004 Dec;34(12):1315-28. doi: 10.1016/j.ibmb.2004.09.003.
Desaturation of fatty acids is a key reaction in the biosynthesis of moth sex pheromones. The main component of Spodoptera littoralis sex pheromone blend is produced by the action of Delta11 and Delta9 desaturases. In this article, we report on the cloning of four desaturase-like genes in this species: one from the fat body (Sls-FL1) and three (Sls-FL2, Sls-FL3 and Sls-FL4) from the pheromone gland. By means of a computational/phylogenetic method, as well as functional assays, the desaturase gene products have been characterized. The fat body gene expressed a Delta9 desaturase that produced (Z)-9-hexadecenoic and (Z)-9-octadecenoic acids in a (1:4.5) ratio, whereas the pheromone gland Sls-FL2 expressed a Delta9 desaturase that produced (Z)-9-hexadecenoic and (Z)-9-octadecenoic acids in a (1.5:1) ratio. Although both Delta9 desaturases produced (Z)-9-tetradecenoic acid from myristic acid, transformed yeast grown in the presence of a mixture of myristic and (E)-11-tetradecenoic acids produced (Z,E)-9,11-tetradecadienoic acid, but not (Z)-9-tetradecenoic acid. The Sls-FL3 gene expressed a protein that produced a mixture of (E)-11-tetradecenoic, (Z)-11-tetradecenoic, (Z)-11-hexadecenoic and (Z)-11-octadecenoic acids in a 5:4:60:31 ratio. Despite having all the characteristics of a desaturase gene, no function could be found for Sls-FL4.
脂肪酸去饱和作用是蛾类性信息素生物合成中的关键反应。棉铃虫性信息素混合物的主要成分是由Δ11和Δ9去饱和酶作用产生的。在本文中，我们报道了该物种中四个类去饱和酶基因的克隆：一个来自脂肪体（Sls-FL1），三个来自性信息素腺体（Sls-FL2、Sls-FL3和Sls-FL4）。通过计算/系统发育方法以及功能分析，对去饱和酶基因产物进行了表征。脂肪体基因表达一种Δ9去饱和酶，该酶以（1:4.5）的比例产生（Z）-9-十六碳烯酸和（Z）-9-十八碳烯酸，而性信息素腺体的Sls-FL2表达一种Δ9去饱和酶，该酶以（1.5:1）的比例产生（Z）-9-十六碳烯酸和（Z）-9-十八碳烯酸。虽然两种Δ9去饱和酶都能从肉豆蔻酸产生（Z）-9-十四碳烯酸，但在肉豆蔻酸和（E）-11-十四碳烯酸混合物存在下生长的转化酵母产生了（Z,E）-9,11-十四碳二烯酸，而不是（Z）-9-十四碳烯酸。Sls-FL3基因表达一种蛋白质，该蛋白质以5:4:60:31的比例产生（E）-11-十四碳烯酸、（Z）-11-十四碳烯酸、（Z）-11-十六碳烯酸和（Z）-11-十八碳烯酸的混合物。尽管Sls-FL4具有去饱和酶基因的所有特征，但未发现其功能。
