Thioredoxin-mimetic peptides as catalysts of S-denitrosylation and anti-nitrosative stress agents
Thioredoxin-mimetic peptides as catalysts of S-denitrosylation and anti-nitrosative stress agents
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DOI：
10.1016/j.freeradbiomed.2014.11.021
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发表时间：
2015-02-01
影响因子：
7.4
通讯作者：
Benhar, Moran
中科院分区：
文献类型：
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作者：
Kronenfeld, Gali;Engelman, Rotem;Benhar, Moran
S亚硝化是一种重要的翻译后调节蛋白质活性的机制，它是将一氧化氮部分与半胱氨酸残基偶联，形成S亚硝硫醇。越来越多的证据表明，高S亚硝化可能导致与多种人类疾病相关的细胞功能障碍。硫氧还蛋白和硫氧还蛋白还原酶在SNO的细胞分解代谢和亚硝化应激保护中的重要作用也越来越受到重视。在此，我们研究了硫氧还蛋白模拟多肽(TXM)、Ac-Cys-Pro-Cys-酰胺(CB3)和Ac-Cys-Gly-Pro-Cys-酰胺(CB4)在无细胞条件下和在亚硝化应激条件下对SNO还原酶的活性和保护作用。体外生化分析表明，血栓素M多肽能还原S-亚硝基谷胱甘肽等小分子亚硝基化合物，是一种通用、高效的蛋白质脱氮剂。特别是，CB3被发现是一种高效的SNO代谢剂。值得注意的是，CB3通过与硫氧还蛋白还原酶结合来促进GSNO还原，从而模拟硫氧还蛋白的活性。此外，在无细胞的裂解物体系中，CB3和CB4都具有NADPH依赖的反硝化蛋白质的活性。进一步的研究表明，TXM多肽可以保护过氧化还蛋白-硫氧还蛋白系统免受SNO依赖的抑制。事实上，SNO抑制的PRX1可以有效地脱氮，并被CB3或CB4重新激活。此外，在体外和完整细胞中，CB3都保护硫氧还蛋白还原酶不受SNO介导的失活。CB3和CB4对GSNO诱导的人神经母细胞瘤SH-SY5Y细胞和大鼠胰岛素瘤INS-1832/13细胞的生长抑制有部分解救作用。综上所述，本研究结果表明TXM多肽具有有效的脱氮活性和保护作用，并提示它们在治疗与亚硝化应激相关的病理条件方面具有潜在的治疗价值。(C)2014 Elsevier Inc.保留所有权利。
S-nitrosylation, the coupling of a nitric oxide moiety to a reactive cysteine residue to form an S-nitrosothiol (SNO), is an important posttranslational mechanism for regulating protein activity. Growing evidence indicates that hyper-S-nitrosylation may contribute to cellular dysfunction associated with various human diseases. It is also increasingly appreciated that thioredoxin and thioredoxin reductase play significant roles in the cellular catabolism of SNO and protection from nitrosative stress. Here, we investigated the SNO reductase activity and protective effects of thioredoxin-mimetic peptides (TXMs), Ac-Cys-Pro-Cys-amide (CB3) and Ac-Cys-Gly-Pro-Cys-amide (CB4), both under cell-free conditions and in nitrosatively stressed cultured cells. In vitro biochemical analyses revealed that the TXM peptides reduced small-molecule SNO compounds, such as S-nitrosoglutathione (GSNO), and acted as general and efficient protein-denitrosylating agents. In particular, CB3 was found to be a highly potent SNO-metabolizing agent. Notably, CB3 mimicked the activity of thioredoxin by coupling with thioredoxin reductase to enhance GSNO reduction. Moreover, in a cell-free lysate system, both CB3 and CB4 synergized with an NADPH-dependent activity to denitrosylate proteins. Further investigation revealed that the TXM peptides protect the peroxiredoxin-thioredoxin system from SNO-dependent inhibition. Indeed, SNO-inhibited Prx1 was efficiently denitrosylated and reactivated by CB3 or CB4. In addition, CB3 protected thioredoxin reductase from SNO-mediated inactivation both in vitro and in intact cells. Finally, CB3 and CB4 partially rescued human neuroblastoma SH-SY5Y cells and rat insulinoma INS-1 832/13 cells from GSNO-induced growth inhibition. Collectively, the present findings indicate the efficient denitrosylation activity and protective effects of TXM peptides and suggest their potential therapeutic value in treating pathological conditions related to nitrosative stress. (C) 2014 Elsevier Inc. All rights reserved.