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：
7924940
负责人：
EDWARD I SOLOMON
金额：
$ 10万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-30 至 2010-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7924940
关键词：
Active Sites Affect Alkaptonuria Alzheimer&apos s Disease Anabolism Antibiotics Antineoplastic Agents Arteriosclerosis Binding Bioremediations Bleomycin Cephalosporins Complex Coupling Crystallography Cysteine DNA Alkylation DNA Repair Data Dioxygen Dioxygenases Disease Drug Design Electronics Environment Enzymes Evaluation Face Funding Goals Heme Heme Iron Hereditary Disease Hypoxia Ions Iron Lactamase Leukotrienes Ligands Ligation Lipoxins Lipoxygenase Malignant Neoplasms Metals Methodology Methods Modeling Molecular Mononuclear Nature Ocular orbit Oxygen Parkinson Disease Penicillins Phenylalanine Hydroxylase Polychlorinated Biphenyls Porphyrins Positioning Attribute Pterins Reaction Regulation Relative (related person)Research Roentgen Rays Role Site Spectrum Analysis Structure Sulfur Temperature Triad Acrylic Resin Tyrosine 3-Monooxygenase Vancomycin absorption base circular magnetic dichroism cofactor defined contribution density disorder prevention electronic structure extradiol dioxygenase improved inhibitor/antagonist insight magnetic field mutant nervous system disorder nitrile hydratase pollutant repaired superoxide reductase theories

项目摘要

DESCRIPTION (provided by applicant): Mononuclear non-heme iron enzymes catalyze a wide range of reactions which either involve O2 activation by a high-spin ferrous site or substrate activation by a high-spin ferric site. Recently a class of non-heme iron enzymes that has thiolate ligation has also been defined. These enzymes are directly related to genetic disorders (phenylketonuria, alkaptonuria), involved in the biosynthesis of antibiotics, lactamase inhibitors, and leukotrienes and lipoxins, important in the repair of DNA alkylation damage, and utilized in the treatment of certain cancers. Non-heme iron enzymes have generally been far more difficult to study than heme enzymes. New spectroscopic methods (emphasizing variable-temperature, variable-field magnetic circular dichroism, and metal K- and L-edge and ligand K-edge X-ray absorption spectroscopy) have been and are being developed which enable the detailed study of these enzymes. Density functional theory calculations supported by these spectroscopic data provide further insight into electronic structure and allow evaluation of reaction coordinates. The goals of this research are to: 1) directly probe the ferrous active sites and their interactions with substrate, cofactor and other relevant factors to elucidate catalytic mechanisms on a molecular level; 2) understand how cosubstrate binding initiates the reaction of the ferrous center with O2; 3) experimentally and theoretically understand the nature of oxygen intermediates and factors that control their reactivity; 4) determine how non-heme relates to heme iron in activating O2; 5) understand the nature of substrate activation by an oxidized iron center, and define the factor(s) leading to selectivity in aromatic ring cleavage; 6) determine the contributions of the highly covalent thiolate S-Fe(lll) bond to the different reactivities of the cysteine liganded non-heme iron enzymes. RELEVANCE: The non-heme iron enzymes are associated with a wide range of diseases including arteriosclerosis, cancer (regulation of hypoxia) and neurological disorders (Alzheimer's, Parkinson's, etc.). These enzymes are also extremely important in the treatment and prevention of disease due to their roles in the biosynthesis of antibiotics (penicillins, cephalosporins, vancomycin), anti-cancer activity (Bleomycin), DNA repair and the bioremediation of pollutants (including PCBs). These studies provide a fundamental understanding of the modes of action of these enzymes enabling strategies to improve or inhibit function and enhance drug design.

描述（由申请人提供）：单核非血红素铁酶催化了广泛的反应，这些反应涉及高自旋位点的O2激活，或者由高型铁位点激活。最近，还定义了一种具有硫醇酸盐结扎的非血红素铁酶。这些酶与遗传疾病（苯可可蛋白，烷基核酸）直接相关，与抗生素，乳糖酶抑制剂，白三烯和脂毒素有关的生物合成，对DNA烷基化损伤的修复，并用于某些癌症的治疗。与血红素酶相比，非血红素铁酶通常要难以研究得多。已经并且正在开发新的光谱法（强调可变温度，可变的磁性圆形二科运动，金属K和L边和配体K-边缘X射线吸收光谱）已经开发并且正在开发，从而可以详细研究这些酶。这些光谱数据支持的密度功能理论计算提供了对电子结构的进一步见解，并允许评估反应坐标。这项研究的目标是：1）直接探测亚铁活性位点及其与底物，辅助因子和其他相关因素的相互作用，以在分子水平上阐明催化机制； 2）了解圆锥形结合如何启动亚铁中心与O2的反应； 3）从实验和理论上了解控制其反应性的氧中间体和因素的性质； 4）确定非血红素在激活O2中与血红素铁的关系； 5）了解氧化铁中心的底物激活的性质，并定义因子导致芳族环裂解的选择性； 6）确定高共价硫醇酸盐S-FE（LLL）键对半胱氨酸配体非血红素铁酶的不同反应性的贡献。相关性：非血红素铁酶与多种疾病有关，包括动脉硬化，癌症（调节缺氧）和神经系统疾病（阿尔茨海默氏症，帕金森氏症等）。这些酶在治疗和预防疾病方面也非常重要，因为它们在抗生素（青霉素，头孢菌素，万古霉素），抗癌活性（Bleyomycin），DNA修复和污染物（包括PCB）的生物修复中的作用（包括PCB）。这些研究提供了对这些酶的作用方式的基本理解，从而使策略改善或抑制功能并增强药物设计。