Ferric and ferrous iron in nitroso-myoglobin: computer simulations of stable and metastable States and their infrared spectra.
Ferric and ferrous iron in nitroso-myoglobin: computer simulations of stable and metastable States and their infrared spectra.
复制标题
亚硝基肌红蛋白中的三价铁和二价铁：稳定和亚稳态及其红外光谱的计算机模拟。
作者：
D. R. Nutt;M. Meuwly
NO与铁的结合参与许多血红素蛋白的生物学功能。与配体如CO和O（2）相反，其仅结合二价铁（Fe（II）），NO结合二价铁和三价铁（Fe（III））。因此，在特定蛋白质中，可以预期天然氧化态是针对所需功能而定制的。本文提出了三价铁与NO相互作用的从头计算势能面，该势能面具有三个极小值，分别对应于eta（1）-NO配位（全局极小值）、eta（1）-ON配位和eta（2）配位.这与Fe（II）-NO的势能面形成对比，Fe（II）-NO的势能面仅显示两个最小值（Fe（II）的eta（2）配位模式是过渡态，而不是最小值）。此外，NO的结合能对于Fe（III）比对于Fe（II）大得多。我们已经进行了分子动力学模拟NO绑定到铁肌红蛋白（Mb（III）），并比较这些Mb（II）获得的结果。在我们的模拟的持续时间（1.5 ns），所有三种结合模式被发现是稳定的，在200 K和瞬态稳定在300 K，最终转化为eta（1）-NO的全球最小构象。我们讨论了这些结果的影响，肌红蛋白的再结合过程的研究。
The binding of NO to iron is involved in the biological function of many heme proteins. Contrary to ligands like CO and O(2), which only bind to ferrous (Fe(II)) iron, NO binds to both ferrous and ferric (Fe(III)) iron. In a particular protein, the natural oxidation state can therefore be expected to be tailored to the required function. Herein, we present an ab initio potential-energy surface for ferric iron interacting with NO. This potential-energy surface exhibits three minima corresponding to eta(1)-NO coordination (the global minimum), eta(1)-ON coordination and eta(2) coordination. This contrasts with the potential-energy surface for Fe(II)-NO, which exhibits only two minima (the eta(2) coordination mode for Fe(II) is a transition state, not a minimum). In addition, the binding energies of NO are substantially larger for Fe(III) than for Fe(II). We have performed molecular dynamics simulations for NO bound to ferric myoglobin (Mb(III)) and compare these with results obtained for Mb(II). Over the duration of our simulations (1.5 ns), all three binding modes are found to be stable at 200 K and transiently stable at 300 K, with eventual transformation to the eta(1)-NO global-minimum conformation. We discuss the implication of these results related to studies of rebinding processes in myoglobin.
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DOI：
10.1006/bbrc.1997.7470
发表时间：
1997-10-09
影响因子：
3.1
作者：
Kharitonov, VG;Russwurm, M;Koesling, D
通讯作者：
Koesling, D
影响因子：
2.9
作者：
Maes, EM;Roberts, SA;Montfort, WR
通讯作者：
Montfort, WR
硝基蛋白 4 的超高分辨率结构中配体诱导的血红素褶皱和弯曲无几何形状。
影响因子：
2.9
作者：
Roberts,SA;Weichsel,A;Qiu,Y;Shelnutt,JA;Walker,FA;Montfort,WR
通讯作者：
Montfort,WR
影响因子：
15
作者：
Merchant, KA;Noid, WG;Fayer, MD
通讯作者：
Fayer, MD