Density functional theory study of Fe(IV) d-d optical transitions in active-site models of class I ribonucleotide reductase intermediate X with vertical self-consistent reaction field method
Density functional theory study of Fe(IV) d-d optical transitions in active-site models of class I ribonucleotide reductase intermediate X with vertical self-consistent reaction field method
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DOI：
10.1021/ic060566
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发表时间：
2006-10-16
影响因子：
4.6
通讯作者：
Noodleman, Louis
中科院分区：
文献类型：
--
作者：
Han, Wen-Ge;Liu, Tiqing;Noodleman, Louis
采用对称性破缺密度泛函理论结合斯莱特过渡态垂直自洽反应场方法，计算了I类核糖核苷酸还原酶（RNR）中间体X的四种活性中心结构模型的Fe（IV）d-d跃迁能.我们的模型I（图1）包含两个μ-氧桥，一个末端水和一个双齿羧酸基团，与实验相比，产生了最好的Fe（IV）d-d跃迁能量。我们以前的研究（J. Am. Soc.2005，127，15778-15790）还表明，天然和突变体Y122 F形式的模型I的大多数其他计算性质，包括几何形状、自旋状态、pK（α）、Fe-57、H-1和O-17超精细张量以及Fe-57穆斯堡尔异构体位移和四极分裂，也是最好的协议与现有的实验数据。该模型可能代表RNR中间态X的活性中心结构。
The Fe(IV) d-d transition energies for four active-site structural models of class I ribonucleotide reductase (RNR) intermediate X have been calculated using broken-symmetry density functional theory incorporated with the Slater transition state vertical self-consistent reaction field methodology. Our model I ( Figure 1), which contains two mu-oxo bridges, one terminal water, and one bidentate carboxylate group, yields the best Fe( IV) d-d transition energies compared with experiment. Our previous study (J. Am. Chem. Soc. 2005, 127, 15778-15790) also shows that most of the other calculated properties of model I in both native and mutant Y122F forms, including geometries, spin states, pK(a)'s, Fe-57, H-1, and O-17 hyperfine tensors, and Fe-57 Mossbauer isomer shifts and quadrupole splittings, are also the best in agreement with the available experimental data. This model is likely to represent the active-site structure of the intermediate state X of RNR.