Dinitrosyliron complexes are the most abundant nitric oxide-derived cellular adduct: biological parameters of assembly and disappearance
Dinitrosyliron complexes are the most abundant nitric oxide-derived cellular adduct: biological parameters of assembly and disappearance
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DOI：
10.1016/j.freeradbiomed.2011.06.030
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发表时间：
2011-10-15
影响因子：
7.4
通讯作者：
Thomas, Douglas D.
中科院分区：
文献类型：
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作者：
Hickok, Jason R.;Sahni, Sumit;Thomas, Douglas D.
众所周知，一氧化氮((中心点)NO)与细胞内的铁和硫醇反应生成二亚硝基络合物(DNIC)。然而，人们对它们的形成和生物命运知之甚少。我们的定量测量表明，DNIC的细胞浓度是所有(中心点)NO加合物中比例最大的(900pmol/mg蛋白质，或45-90微米)。利用小鼠巨噬细胞(RAW 264.7)，我们测量了内源性和外源性(中心点)NO与铁和O(2)浓度相关的DNIC组装和消失的数量和动力学。DNIC的量等于或大于测量的可络合铁的量，并取决于(中心点)无暴露的剂量和持续时间。DNIC的形成与iNOS的上调相平行，并且发生在低生理(中心点)的NO浓度(50-500 nM)时。降低O(2)浓度可降低酶促合成NO的速率，但不影响DNIC的生成量。时间测量显示，DNIC以氧不依赖的方式消失(t(1/2)=80min)，并在去除(中心点)NO源后很长时间内仍可被检测到(>；24小时)。这些结果表明，DNIC将在(中心点)NO产生的所有蜂窝环境下形成，并且必须始终考虑DNIC对(中心点)NO的众多观测效应的贡献。(C)2011 Elsevier Inc.保留所有权利。
It is well established that nitric oxide ((center dot)NO) reacts with cellular iron and thiols to form dinitrosyliron complexes (DNIC). Little is known, however, regarding their formation and biological fate. Our quantitative measurements reveal that cellular concentrations of DNIC are proportionally the largest of all (center dot)NO-derived adducts (900 pmol/mg protein, or 45-90 mu M). Using murine macrophages (RAW 264.7), we measured the amounts, and kinetics, of DNIC assembly and disappearance from endogenous and exogenous sources of (center dot)NO in relation to iron and O(2) concentration. Amounts of DNIC were equal to or greater than measured amounts of chelatable iron and depended on the dose and duration of (center dot)NO exposure. DNIC formation paralleled the upregulation of iNOS and occurred at low physiologic (center dot)NO concentrations (50-500 nM). Decreasing the O(2) concentration reduced the rate of enzymatic (center dot)NO synthesis without affecting the amount of DNIC formed. Temporal measurements revealed that DNIC disappeared in an oxygen-independent manner (t(1/2) = 80 min) and remained detectable long after the (center dot)NO source was removed (>24 h). These results demonstrate that DNIC will be formed under all cellular settings of (center dot)NO production and that the contribution of DNIC to the multitude of observed effects of (center dot)NO must always be considered. (C) 2011 Elsevier Inc. All rights reserved.