Nitric oxide inhibits peroxidase activity of cytochrome c• cardiolipin complex and blocks cardiolipin oxidation
Nitric oxide inhibits peroxidase activity of cytochrome c• cardiolipin complex and blocks cardiolipin oxidation
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DOI：
10.1074/jbc.m509507200
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发表时间：
2006-05-26
影响因子：
4.8
通讯作者：
Kagan, Valerian E.
中科院分区：
文献类型：
--
作者：
Vlasova, Irina I.;Tyurin, Vladimir A.;Kagan, Valerian E.
在细胞凋亡的早期阶段，NO的产生增加表明其通过尚未确定的机制参与程序性细胞死亡的调节。最近，一个重要的作用，催化活性的过氧化物酶形式的五配位细胞色素c（细胞色素c）在一个复杂的与cardiopecific磷脂，心磷脂（CL），已被证明在执行过程中的凋亡程序。因为Cyt C（.）CL复合物作为CL加氧酶，选择性地氧化凋亡细胞中的CL，该反应依赖于蛋白质衍生的（酪氨酰）自由基的产生，我们推测，结合和亚硝基化的cyt c调节CL氧化。在这里，我们证明了低温电子顺磁共振光谱，CL促进铁和亚铁态的细胞色素C与NO和NO-，分别产生的混合物的五和六配位亚硝基化的细胞色素C的相互作用。在亚硝基化的CytC（.）CL复合物，NO化学反应与H2 O2激活的过氧化物酶中间体导致其还原。使用直接电子顺磁共振测量以及免疫自旋捕集与抗体对蛋白质5，5-二甲基-1-吡咯啉N-氧化物-硝酮加合物的H2 O2诱导的蛋白质衍生自由基的NO供体的剂量依赖性淬灭。在NO供体的存在下，H2 O2诱导的寡聚体形式的细胞色素c阳性染色的3-硝基酪氨酸确认NO对酪氨酸自由基的细胞色素c的反应性。NO与细胞色素c（.）CL复合物抑制其过氧化物酶活性与三种不同的底物：CL，依托泊苷，和3，3 '-二氨基联苯胺。考虑到CL氧化在细胞凋亡中的重要性，利用质谱分析来评估NO对1，1 '2，2'-叔他林油酰心磷脂氧化的影响。NO能有效抑制CytC过氧化物酶催化的1，1 '2，2'-叔他林油酰心磷脂氧化因此，NO可作为细胞色素c（.）CL络合物。
The increased production of NO during the early stages of apoptosis indicates its potential involvement in the regulation of programmed cell death through yet to be identified mechanisms. Recently, an important role for catalytically competent peroxidase form of pentacoordinate cytochrome c (cyt c) in a complex with a mitochondriaspecific phospholipid, cardiolipin (CL), has been demonstrated during execution of the apoptotic program. Because the cyt c(.)CL complex acts as CL oxygenase and selectively oxidizes CL in apoptotic cells in a reaction dependent on the generation of protein-derived (tyrosyl) radicals, we hypothesized that binding and nitrosylation of cyt c regulates CL oxidation. Here we demonstrate by low temperature electron paramagnetic resonance spectroscopy that CL facilitated interactions of ferro-and ferri-states of cyt c with NO and NO-, respectively, to yield a mixture of penta- and hexa-coordinate nitrosylated cyt c. In the nitrosylated cyt c(.)CL complex, NO chemically reacted with H2O2-activated peroxidase intermediates resulting in their reduction. A dose-dependent quenching of H2O2-induced protein-derived radicals by NO donors was shown using direct electron paramagnetic resonance measurements as well as immuno-spin trapping with antibodies against protein 5,5-dimethyl-1-pyrrolineN-oxide-nitrone adducts. In the presence of NO donors, H2O2-induced oligomeric forms of cyt c positively stained for 3-nitrotyrosine confirming the reactivity of NO toward tyrosyl radicals of cyt c. Interaction of NO with the cyt c(.)CL complex inhibited its peroxidase activity with three different substrates: CL, etoposide, and 3,3'-diaminobenzidine. Given the importance of CL oxidation in apoptosis, mass spectrometry analysis was utilized to assess the effects of NO on oxidation of 1,1'2,2'-tertalinoleoyl cardiolipin. NO effectively inhibited 1,1'2,2'-tertalinoleoyl cardiolipin oxidation catalyzed by the peroxidase activity of cyt c. Thus, NO can act as a regulator of peroxidase activity of cyt c(.)CL complexes.