ELECTRONIC STRUCTURE OF FE-OXO AND MN-OXO COMPLEXES

这项提议涉及到量子力学的使用。 计算和随后的分析，以检查电子 双核、多核Fe-O络合物和Mn-O的结构 络合物作为金属蛋白活性中心的相关模型 系统。Fe-O络合物存在于：(A)核糖核苷酸中 还原酶，(B)甲烷单加氧酶，(C)紫酸 磷酸酶，和(D)氯氰菊酯。一种多核锰氧络合物 发生在放氧复合体中的活性部位 光系统II。 我们所有的计算都将是Xα或局部自旋 密度自洽场类型。我们将系统地研究 相关模型络合物作为氧化态的函数， 配位几何构型和底物配体的结合 反应中间体。这些计算结果将与 磁化率和磁化率的实验结果 穆斯堡尔谱、电子自旋共振和/或光学光谱学 用于蛋白质和合成类似物。此外，我们将研究 电子密度分布和自旋密度分布 一些细节，因为这些功能应该紧密关联 具有催化作用的机理。定性和定量配基 我们还将探索束缚能量学。我们的目标是联系 预测和实验属性，以及获得洞察力 转化为这些酶的催化功能和调节。

This proposal involves the use of quantum mechanical calculations and subsequent analysis to examine the electronic structure of dinuclear and polynuclear Fe-O complexes and Mn-O complexes as relevant models for active sites of metalloprotein systems. Fe-O complexes are found in: (a) ribonucleotide reductase, (b) methane monooxygenase, (c) purple acid phosphatases,and (d) hemerythrin. A polynuclear Mn-O complex occurs at the active site in the oxygen evolving complex of photosystem II. All of our calculations will be of the Xalpha or local spin density self consistent field type. We will systematically study relevant model complexes as a function of oxidation state, coordination geometry, and binding of substrate ligands or reaction intermediates. The calculations will be compared with experimental results by magnetic susceptibility, and by Mossbauer, electron spin resonance and/or optical spectroscopies for proteins and synthetic analogues. Further, we will examine electron density distributions and spin density distributions in some detail since these features should be closely associated with catalytic mechanism. Qualitative and quantitative ligand binding energetics will also be explored. Our goal is to relate predicted and experimental properties as well as to gain insight into catalytic function and regulation in these enzymes.