Mitochondrial thioredoxin-2 from disk abalone (Haliotis discus discus):: Molecular characterization, tissue expression and DNA protection activity of its recombinant protein
Mitochondrial thioredoxin-2 from disk abalone (Haliotis discus discus):: Molecular characterization, tissue expression and DNA protection activity of its recombinant protein
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DOI：
10.1016/j.cbpb.2007.12.009
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发表时间：
2008-04-01
影响因子：
2.2
通讯作者：
Lee, Jehee
中科院分区：
文献类型：
--
作者：
De Zoysa, Mahanama;Pushpamali, Wickramaarachchilage Anoja;Lee, Jehee
硫氧还蛋白-2是线粒体特异性的硫氧还蛋白（TRx）超家族成员，在线粒体抗氧化系统中起重要作用。编码线粒体TRx-2的基因从盘鲍鱼（halotis discus discus） cDNA文库中分离，记为AbTRx-2。全长1214bp，开放阅读框519bp，编码173个氨基酸。AbTRx-2在（96）WCGPC（100）处显示特征性的TRx活性位点，在n端氨基酸序列上显示线粒体靶向肽。推导的氨基酸比较结果表明，AbTRx-2与非洲爪蟾TRx-2和人类TRx-2的同源性分别为43%和42%。纯化的重组AbTRx-2融合蛋白被证明可以催化胰岛素还原，并保护超螺旋质粒DNA免受金属催化生成活性氧引起的损伤。在鳃、套、性腺、外展肌、消化道和血细胞中检测到组成型AbTRx-2 mRNA，且具有组织特异性。AbTRx-2 mRNA在注射H2O2后3 h开始在鳃和消化道组织中表达上调，并在6 h时维持较高水平。我们的研究结果表明，TRx-2可能通过催化蛋白质二硫还原、清除ROS和减轻DNA损伤来调节线粒体氧化应激。(c) 2008爱思唯尔公司版权所有。
Thioredoxin-2 is a mitochondria-specific member of the thioredoxin (TRx) super-family that plays an important role as a component of the mitochondrial antioxidant system. The gene coding mitochondrial TRx-2 was isolated from the disk abalone (Haliotis discus discus) cDNA library, denoted as AbTRx-2. It contains 1214-bp full length with 519-bp open reading frame, encoding 173 amino acids. AbTRx-2 showed characteristic TRx active site at (96)WCGPC(100) and mitochondrial targeting peptide at the N-terminal amino acid sequence. The deduced amino acid comparison showed that AbTRx-2 shares 43 and 42% identity with Xenopus laevis and human TRx-2, respectively. Purified recombinant AbTRx-2 fusion protein was shown to catalyze insulin reduction and protect supercoiled plasmid DNA from damages induced by metal-catalyzed generation of reactive oxygen species. Constitutive AbTRx-2 mRNA was detected in gill, mantle, gonad, abductor muscle, digestive tract, and hemocytes, in a tissue specific manner. The AbTRx-2 mRNA was up-regulated in gill and digestive tract tissues initially at 3 h post-injection of H2O2 and maintained higher level at 6 h. Our results suggest that abalone TRx-2 may play an important role in regulating oxidative stress in mitochondria by catalyzing protein disulfide reduction, scavenging of ROS, and minimizing the DNA damage. (c) 2008 Elsevier Inc. All rights reserved.