中文摘要：

利用PCR和RACE技术从皱纹盘鲍（Haliotis discus hannai）肌肉中克隆亮氨酸氨肽酶基因cDNA序列,并对其结构进行分析。皱纹盘鲍亮氨酸氨肽酶（Haliotis discus hannai leucine aminopeptidase,Hdh-LAP）cDNA全长共3251 bp,包含5＇非编码区（5＇UTR）56 bp,3＇非编码区（3＇UTR）651 bp,开放阅读框（open reading frame,ORF）2544 bp,共编码847个氨基酸残基。多序列比对结果显示,该氨基酸序列与太平洋牡蛎（Crassostrea gigas）、霸王莲花青螺（Lottia gigantea）、囊舌虫（Saccoglossus kowalevskii）的亮氨酸氨肽酶序列相似性分别为85%、68%和61%。预测Hdh-LAP基因编码蛋白质的相对分子质量为95.09 ku,理论等电点为5.16。Hdh-LAP蛋白质的二级结构以α-螺旋和无规则卷曲为主,其中α-螺旋占38.02%,无规则卷曲占30.11%,β-折叠占22.43%,β-转角占9.45%。Hdh-LAP主要分布在细胞质（59.2%）、线粒体（10.0%）和溶酶体（10%）中,推测其可能在能量代谢和辅因子的生物合成过程中发挥信号转导和转录因子调控的作用。系统发育关系分析结果显示,Hdh-LAP与牡蛎亮氨酸氨肽酶关系最近。荧光定量PCR结果表明,Hdh-LAP基因在鲍肌肉、肝胰腺、性腺、血淋巴细胞、腮、外套膜等6个组织中均有表达,在血淋巴细胞中表达量最高,肌肉次之,性腺最少。

英文摘要：

The full-length cDNA of a leucine aminopeptidase from abalone（ Haliotis discus hannai）（ Hdh-LAP） was cloned by PCR and RACE technology. The full length of Hdh-LAP gene was 3251 bp,which included a 5＇ untranslated region（ UTR） of 56 bp,a 3＇UTR of 651 bp and an open reading frame（ ORF） of 2544 bp coding 847 amino acid residues with an estimated molecular weight of 95. 09 ku and a theoretical isoelectric point of 5. 16. Interestingly,the amino acid sequences of Hdh-LAP showed a high degree of identity（ 85%） to those of Crassostrea gigas and lower degree of identities（ 68% and 61%） to those of Lottia gigantea and Saccoglossus kowalevskii.The secondary structure of Hdh-LAP was mainly composed of α-helices（ 38. 02%） and random coil（ 30. 11%）. Subcellular localization analysis revealed that Hdh-LAP was mainly distributed in the cytoplasm（ 59. 2%）,mitochondria（ 10%） and lysosome（ 10%）,indicating that Hdh-LAP may play a role in signal transduction and transcriptional regulation in the energy metabolism and cofactor biosynthesis. Phylogenetic analysis exhibited that Hdh-LAP was closely related to LAP from Crassostrea gigas. Quantitative real-time PCR（ qPCR） showed that LAP gene was expressed in all tissues,with highest expression levels in the hemocytes and muscle,while barely detectable in the hepatopancreas,gills,mantle and gonad.