CYP341B14: a cytochrome P450 involved in the specific epoxidation of pheromone precursors in the fall webworm Hyphantria cunea.
CYP341B14: a cytochrome P450 involved in the specific epoxidation of pheromone precursors in the fall webworm Hyphantria cunea.
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DOI：
10.1016/j.ibmb.2014.09.009
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发表时间：
2014-11
影响因子：
3.8
通讯作者：
Y. Rong;T. Fujii;S. Katsuma;Masanobu Yamamoto;T. Ando;Y. Ishikawa
中科院分区：
文献类型：
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作者：
Y. Rong;T. Fujii;S. Katsuma;Masanobu Yamamoto;T. Ando;Y. Ishikawa
美国白蛾（Hyphantria cunea）性信息素的4种成分中有2种分子中含有环氧环，即顺式-9，10-环氧-（3 Z，6 Z）-3，6-二十一碳二烯和顺式-9，10-环氧-（3 Z，6 Z）-1，3，6-二十一碳三烯。这些化合物被认为是由膳食亚麻酸通过以下酶促反应生物合成的：链延长、末端去饱和（在后一种组分的情况下）、脱羧和环氧化。这种生物合成的最后一步，环氧化，是已知的，特别是发生在性信息素腺体的女性。我们确定了参与信息素前体的环氧化的酶，通过关注细胞色素P450，这是已知的催化各种化合物的氧化。从美国白蛾性信息素腺体cDNA文库中鉴定出3个P450样序列（Hc_epo1、Hc_epo2和Hc_epo3）。在这些克隆中，只有Hc_epo1在信息素腺体中特异表达。Hc_epo1基因全长1527 bp，编码509个氨基酸，预测分子量为57.9 kDa。推导的Hc_epo1氨基酸序列具有P450的特征。系统发育分析表明，Hc_epo1属于CYP 341家族中的CYP 341 B分支。因此，它被命名为CYP 341 B14。随后使用瞬时表达CYP 341 B14的Sf-9细胞的功能测定证明，该P450蛋白能够特异性地环氧化信息素前体（3 Z，6 Z，9 Z）-3，6，9-二十一碳三烯中第9位的（Z）-双键。
Two of the four sex pheromone components in the fall webwormHyphantria cunea(Lepidoptera: Arctiidae),cis-9,10-epoxy-(3Z,6Z)-3,6-henicosadiene andcis-9,10-epoxy-(3Z,6Z)-1,3,6-henicosatriene, possess an epoxy ring within their molecules. These compounds have been suggested to be biosynthesized from dietary linolenic acid via the following enzymatic reactions; chain elongation, terminal desaturation (in the case of the latter component), decarboxylation, and epoxidation. The last step of this biosynthesis, epoxidation, is known to occur specifically in the sex pheromone gland of females. We identified the enzyme involved in the epoxidation of pheromone precursors by focusing on cytochromes P450, which are known to catalyze the oxidation of various compounds. Three P450-like sequences (Hc_epo1,Hc_epo2, andHc_epo3) were identified in the cDNA library prepared from the sex pheromone gland ofH. cunea. Among these clones, onlyHc_epo1was specifically expressed in the pheromone gland. The full-length sequence ofHc_epo1contained an ORF of 1527 bp, which encoded a protein of 509 amino acids with a predicted molecular weight of 57.9 kDa. The deduced Hc_epo1 amino acid sequence possessed the characteristics of P450. A phylogenetic analysis of the sequence indicated that Hc_epo1 belonged to the CYP341B clade in the CYP341 family. Therefore, it was named CYP341B14. A subsequent functional assay using Sf-9 cells transiently expressing CYP341B14 demonstrated that this P450 protein was able to specifically epoxidize a (Z)-double bond at the 9th position in the pheromone precursor, (3Z,6Z,9Z)-3,6,9-henicosatriene.