Redox-sensitivity and site-specificity of S- and N- denitrosation in proteins.
Redox-sensitivity and site-specificity of S- and N- denitrosation in proteins.
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DOI：
10.1371/journal.pone.0014400
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发表时间：
2010-12-21
期刊：
影响因子：
3.7
通讯作者：
Jourd'heuil D
中科院分区：
文献类型：
--
作者：
Jourd'heuil FL;Lowery AM;Melton EM;Mnaimneh S;Bryan NS;Fernandez BO;Park JH;Ha CE;Bhagavan NV;Feelisch M;Jourd'heuil D
S亚硝化-蛋白质半胱氨酸残基上形成S-亚硝硫醇(RSNO)-是一种翻译后修饰，参与信号转导和一氧化氮(NO)转运。最近的研究也表明N-亚硝胺(RNNO)在体内蛋白质中的形成，尽管它们的生物学意义仍然不清楚。在这项研究中，我们描述了一种基于氧化还原的机制，通过这种机制，蛋白质中的N-亚硝基-色氨酸残基可以被反硝化。谷胱甘肽(GSH)对N-乙酰-亚硝基色氨酸(NANT)的反硝化反应需要分子氧，并受超氧化物歧化酶(SOD)的抑制。只有在无氧或有超氧化物歧化酶存在时，才能观察到反硝化生成S-亚硝基谷胱甘肽(GSNO)。以突变型重组人血清白蛋白(HSA)为底物，研究了GSH对蛋白质的脱氮作用。在好氧条件下，只有Trp-214和Cys-37两个残基被NO亚硝化。HSA中的亚硝基-Trp-214对GSH或抗坏血酸的反硝化反应不敏感，而Cys-37在GSH存在下反硝化反应明显，而抗坏血酸的反硝化作用不明显。在含有Trp-214的螺旋II的多肽片段中恢复了Trp-214的GSH依赖的反硝化反应。最后，细胞裂解产物与NANT的孵育显示了一种与GSNO不同的蛋白质亚硝化模式。我们认为GSH对亚硝化色氨酸的反硝化是通过亚硝基Trp均相裂解到NO和Trp氨基自由基来进行的，这是由GSH氧化生成GSSG产生的超氧化物所驱动的。总体而言，Trp残基对氧化还原活性生物分子的可及性决定了蛋白质相关亚硝基物种的稳定性，因此在HSA的情况下，N-亚硝基-Trp-214对低分子抗氧化剂的反硝化不敏感。此外，RNNO可以产生游离的NO，并以氧依赖的方式转移其NO部分，尽管位点特异性似乎与RSNO显著不同。
S-nitrosation – the formation of S-nitrosothiols (RSNOs) at cysteine residues in proteins – is a posttranslational modification involved in signal transduction and nitric oxide (NO) transport. Recent studies would also suggest the formation of N-nitrosamines (RNNOs) in proteins in vivo, although their biological significance remains obscure. In this study, we characterized a redox-based mechanism by which N-nitroso-tryptophan residues in proteins may be denitrosated. The denitrosation of N-acetyl-nitroso Trp (NANT) by glutathione (GSH) required molecular oxygen and was inhibited by superoxide dismutase (SOD). Transnitrosation to form S-nitrosoglutathione (GSNO) was observed only in the absence of oxygen or presence of SOD. Protein denitrosation by GSH was studied using a set of mutant recombinant human serum albumin (HSA). Trp-214 and Cys-37 were the only two residues nitrosated by NO under aerobic conditions. Nitroso-Trp-214 in HSA was insensitive to denitrosation by GSH or ascorbate while denitrosation at Cys-37 was evident in the presence of GSH but not ascorbate. GSH-dependent denitrosation of Trp-214 was restored in a peptide fragment of helix II containing Trp-214. Finally, incubation of cell lysates with NANT revealed a pattern of protein nitrosation distinct from that observed with GSNO. We propose that the denitrosation of nitrosated Trp by GSH occurs through homolytic cleavage of nitroso Trp to NO and a Trp aminyl radical, driven by the formation of superoxide derived from the oxidation of GSH to GSSG. Overall, the accessibility of Trp residues to redox-active biomolecules determines the stability of protein-associated nitroso species such that in the case of HSA, N-nitroso-Trp-214 is insensitive to denitrosation by low-molecular-weight antioxidants. Moreover, RNNOs can generate free NO and transfer their NO moiety in an oxygen-dependent fashion, albeit site-specificities appear to differ markedly from that of RSNOs.
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DOI：
10.1073/pnas.0306706101
发表时间：
2004-03-23
影响因子：
11.1
作者：
Bryan, NS;Rassaf, T;Feelisch, M
通讯作者：
Feelisch, M
影响因子：
4.8
作者：
Bhattacharya, AA;Curry, S;Franks, NP
通讯作者：
Franks, NP
影响因子：
11
作者：
Harohalli, K;Petersen, CE;Bhagavan, NV
通讯作者：
Bhagavan, NV
影响因子：
3.9
作者：
Li, S;Whorton, AR
通讯作者：
Whorton, AR
DOI：
10.1039/p29820001383
发表时间：
1982-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
影响因子：
--
作者：
MEYER, TA;WILLIAMS, DLH;OOI, SL
通讯作者：
OOI, SL