Characterization of a silkworm thioredoxin peroxidase that is induced by external temperature stimulus and viral infection
Characterization of a silkworm thioredoxin peroxidase that is induced by external temperature stimulus and viral infection
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DOI：
10.1016/j.ibmb.2004.09.008
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发表时间：
2005-01-01
影响因子：
3.8
通讯作者：
Jin, BR
中科院分区：
文献类型：
--
作者：
Lee, KS;Kim, SR;Jin, BR
还原H 0 的硫氧还蛋白过氧化物酶（TPx）首先在鳞翅目昆虫蚕Bombyx mori 中得到表征。 B. mori TPx (BmTPx) cDNA 包含一个 585 bp 的开放阅读框，编码 195 个氨基酸残基，并具有两个半胱氨酸残基，这是过氧化还原蛋白家族 2-Cys 亚组的特征。 BmTPx cDNA 的推导氨基酸序列与果蝇 (DmTPx-1) 的同一性为 78%，与埃及伊蚊 (AaTPx) 的同一性为 73%，与其他昆虫 2-Cys TPx 的同一性为 54-48%。编码BmTPx的cDNA在杆状病毒感染的昆虫SP)细胞中表达为25-kDa多肽。纯化的重组 BmTPx 在二硫苏糖醇存在或提供电子的情况下可还原 H2O2，并且在硫氧还蛋白作为电子供体存在的情况下具有活性。 Northern 印迹分析显示所有检查的组织中均存在 BmTPx 转录本。 Western blot分析显示BmTPx存在于脂肪体和中肠中，但不存在于血淋巴中，表明BmTPx是不可分泌的。当将H2O2注入家蚕幼虫体腔时，脂肪体组织中BmTPx mRNA表达上调。有趣的是，当家蚕幼虫暴露于低温（4℃）和高温（37℃）或杆状病毒感染时，脂肪体内BmTPx酶的表达水平特别高，这表明BmTPx似乎对温度刺激和病毒感染引起的氧化应激发挥保护作用。 (C) 2004 Elsevier Ltd. 保留所有权利。
A thioredoxin peroxidase (TPx) that reduces H 0, was firstly characterized in the lepidopteran insect, silkworm Bombyx mori. The B. mori TPx (BmTPx) cDNA contains an open reading frame of 585 bp encoding 195 amino acid residues and possesses two cysteine residues that are characteristic of 2-Cys subgroup of peroxiredoxin family. The deduced amino acid sequence of the BmTPx cDNA showed 78% identity to Drosophila melanogaster (DmTPx-1), 73% to Aedes aegypti (AaTPx), and 54-48% to other insect 2-Cys TPx. The cDNA encoding BmTPx was expressed as a 25-kDa polypeptide in baculovirus-infected insect SP) cells. The purified recombinant BmTPx was shown to reduce H2O2 in the presence or electrons donated by dithiothreitol and shown to be active in the presence of thioredoxin as electron donor. Northern blot analysis revealed the presence of BmTPx transcripts in all tissues examined. Western blot analysis showed the presence of the BmTPx in the fat body and midgut, but not in the hemolymph, Suggesting the BmTPx is not secretable. When H2O2 was injected into body cavity of B. mori larva, BmTPx mRNA expression was up-regulated in the fat body tissues. Interestingly, the expression levels of BmTPx enzyme in the fat body were particularly high when B. mori larva was exposed at low (4 degreesC) and high (37 degreesC) temperatures or baculovirus infection, suggesting that the BmTPx seems to play a protective role against oxidative stress caused by temperature stimuli and viral infection. (C) 2004 Elsevier Ltd. All rights reserved.