Spectroscopic Studies of Mononuclear Non-Heme Fe Enzymes

单核非血红素铁酶的光谱研究

基本信息

批准号：
8270473
负责人：
EDWARD I SOLOMON
金额：
$ 39.53万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-07-01 至 2015-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8270473
关键词：
Active Sites Affect Anabolism Antibiotics Antineoplastic Agents Area Asthma Atherosclerosis Binding Biological Factors Biology Bioremediations Bleomycin Catechols Chemistry Cleaved cell Collagen Complex Coupled DNA DNA Repair Dependence Development Dioxygen Dioxygenases Disease Electronics Environment Enzymes Face Freezing Funding Goals Gray unit of radiation dose Heme Heme Iron Hereditary Disease Hydroxylation Hypoxia Iron Lead Ligands Ligation Lipoxygenase Methodology Methods Modeling Molecular Mono-S Mononuclear Mutation Nature Nuclear Oxygen Pharmaceutical Preparations Phenylketonurias Porphyrins Proteins Pterins Reaction Regulation Relative (related person)Research Research Project Grants Roentgen Rays Series Signal Transduction Site Solutions Spectrum Analysis Structure Study models Temperature Triad Acrylic Resin Tyrosinemias absorption cancer therapy carboxylate circular magnetic dichroism cofactor density electronic structure enzyme model extradiol dioxygenase frontier halogenation insight molecular orbital oxidation taurine dioxygenase theories

项目摘要

DESCRIPTION (provided by applicant): Non-heme iron (NHFe) enzymes are ubiquitous in biology and catalyze a wide range of reactions involving dioxygen. These include mono- and dioxygenation, H-atom abstraction for hydroxylation, halogenation and desaturation and electrophilic aromatic attack. The non-heme enzymes can be divided into classes that use a ferrous center to activate dioxygen and classes that use a ferric site to activate substrate for the spin forbidden reaction with dioxygen. The ferrous enzymes include the pterin and ?-ketoglutarate dependent dioxygenases, the Rieske dioxygenases, the extradiol dioxygenases and the anticancer drug Bleomycin. While the natures of the cosubstrate-FeII interactions that activate O2 are not defined, peroxo and high valent oxo intermediates have been trapped in a number of these enzymes and relevant model complexes of these intermediates exist with abiological ligation. The ferric/substrate activating enzymes are the lipoxygenases and the intradiol dioxygenases. Lipoxygenase is thought to activate substrate by H-atom abstraction while for the intradiol dioxygenases substrate activation is thought to occur through direct coordination to the ferric center. No intermediate has been trapped for either enzyme. The non-heme iron enzymes have generally been challenging to study due to their lack of spectral features. The goals of this research project have been to generate new spectroscopic methods and approaches to study the non-heme iron enzymes. These methods are used to experimentally define substrate and cofactor interactions with the iron sites and the natures of the intermediates and their key geometric and electronic contributions to reactivity. Further these experimental results are strongly coupled with density functional theory (DFT) calculations to define structure/function correlations, to understand how the iron site is activated for reaction by substrate or cofactor binding, and to understand their reaction mechanisms on a molecular level. Spectroscopic methods are also being developed to directly probe iron centers in highly covalent porphyrin environments to understand how heme relates to NHFe in oxygen activation and in factors that control reactivity.

描述（由申请人提供）：非血红素（NHFE）酶在生物学中无处不在，并催化涉及二氧化物的广泛反应。这些包括单一和二氧化，H原子抽象用于羟基化，卤代化和去饱和以及电芳族芳香攻击。非血红素酶可以分为使用亚铁中心激活二恶英和使用铁位点激活底物的类别的类别，以激活与二恶英的自旋禁止反应。亚铁酶包括翼蛋白和酮戊二酸二加氧酶，rieske dioxygyass，介入二加氧酶和抗癌药物博来霉素。尽管未定义激活O2的cosubstrate-FEII相互作用的本质，但在许多这些酶中，过氧和高的氧中间体被困在许多这些中间体的许多模型复合物中。铁/底物激活酶是脂氧酶和二氧二加氧酶的内二氧化酶。人们认为脂氧酶通过H原子抽象激活底物，而对于内二醇二加氧酶的底物底物激活被认为是通过直接协调到铁中心而发生的。没有中间体被困于任何一种酶。由于缺乏光谱特征，非血红素铁酶通常一直在研究。该研究项目的目标是生成新的光谱方法和研究非血红素铁酶的方法。这些方法用于实验定义与铁位点以及中间体的本质及其对反应性的关键几何和电子贡献的底物和辅因子相互作用。此外，这些实验结果与密度功能理论（DFT）计算强烈结合，以定义结构/功能相关性，以了解如何通过底物或辅助因子结合激活铁位点以进行反应，并在分子水平上了解其反应机制。还开发了光谱法以直接探测高价值的卟啉环境中的铁中心，以了解血红素与氧气激活和控制反应性的因素的关系。