ELECTRONIC STRUCTURE OF FE-OXO AND MN-OXO COMPLEXES

FE-OXO 和 MN-OXO 配合物的电子结构

• 批准号: 3302315
• 负责人: Louis Noodleman
• 金额: $ 10.2万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-05-01 至 1992-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3302315
• 关键词: Mossbauer spectrometry; acid phosphatase; active sites; biomagnetism; catalyst; chemical models; electron spin resonance spectroscopy; electronic spectra; enzyme model; iron oxide; iron sulfur protein; manganese; metalloproteins; oxidoreductase; oxygenases; quantum chemistry

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.

该提案涉及使用量子力学 计算和随后的分析以检查电子 双核和多核 Fe-O 配合物和 Mn-O 的结构 配合物作为金属蛋白活性位点的相关模型 系统。 Fe-O 复合物存在于： (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) 血红蛋白。 多核Mn-O配合物 发生在放氧复合物的活性位点 光系统 II. 我们所有的计算都将是 Xalpha 或局部自旋 密度自洽场类型。 我们将系统地学习 作为氧化态函数的相关模型复合物， 配位几何形状，以及底物配体的结合或 反应中间体。 计算结果将与 磁化率实验结果，以及 穆斯堡尔、电子自旋共振和/或光学光谱 用于蛋白质和合成类似物。 进一步，我们将检查 电子密度分布和自旋密度分布 一些细节，因为这些功能应该密切相关 具有催化机制。 定性和定量配体 还将探索结合能量学。 我们的目标是联系 预测和实验特性以及获得洞察力 深入了解这些酶的催化功能和调节。