Principles of C-H and O2 Activation

C-H和O2活化原理

基本信息

批准号：
7937495
负责人：
JUDITH P KLINMAN
金额：
$ 10.96万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
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 2010-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7937495
关键词：
Active Sites Aerobic Amines Aromatic Amines Benchmarking Bicarbonates Binding Biomimetics Carbon Catalysis Characteristics Charge Copper Cyanides Cyclopropanes Cysteine Dependence Dependency Deuterium Distal Dopamine Drug Design Environment Enzyme Activation Enzymes Ethylenes Event Excision Family Family member Flavins Free Radicals Future Galactose Oxidase Gases Generations Goals Guidelines Heme Heme Iron Homologous Gene Hormones Hydrogen Hydrogen Bonding Hydroxylation Investigation Ions Isoenzymes Isotopes Kinetics Label Laboratories Laboratory Finding Life Ligands Link Lipoxygenase Lipoxygenase 1 Maps Measurement Measures Mechanics Mixed Function Oxygenases Motion Mutagenesis Mutate Nature Neurotransmitters Nonheme Iron Proteins Oxidases Oxygen Pathway interactions Peptides Pichia Play Positioning Attribute Process Production Property Protein Dynamics Protein Region Proteins Protons Publishing Reaction Reactive Oxygen Species Reducing Agents Resistance Roentgen Rays Role Series Side Site Site-Directed Mutagenesis Solvents Source Soybeans Specificity Structure Substrate Specificity System Temperature Tertiary Protein Structure Testing Tyramine Work Yeasts adduct alpha ketoglutarate ascorbate base carboxylate catalyst crosslink cyclopropane design diamino oxhydrase driving force electron donor flexibility fruits and vegetables glucose oxidase inhibitor/antagonist insight meetings member mutant novel oxidation particle peptidylglycine alpha-amidating monooxygenase pressure programs protein structure prototype public health relevance quantum research study taurine dioxygenase taurine-alpha-ketoglutarate dioxygenase

项目摘要

DESCRIPTION (provided by applicant): The overarching aim of this application is to elucidate the principles that govern enzyme catalyzed C-H and O2 activation processes. Studies of C-H activation (proton, hydride and hydrogen atom) are focused on understanding the role of quantum mechanical hydrogen transfer and its link to protein structure and dynamics. The investigation of oxygen activation is directed toward reactions that remain particularly enigmatic with regard to the nature of the oxygen species and/or the reaction pathway that leads to product formation. The pharmacologically important enzyme lipoxygenase has become a center pin of studies aimed at understanding the role of hydrogen tunneling in enzyme catalysis; future studies include probes of protein motions and their links to the tunneling event, the impact of high pressure on tunneling, and the characterization of a thermophilic homolog for comparison to the mesophilic soybean lipoxygenase. The channeling of oxygen within a discrete region of protein, orthogonal to the substrate-binding pocket, has been postulated in lipoxygenase; this will be further tested using site-specific mutagenesis. Tyramine ?- monooxygenase (T2M) is a member of a small family of eukaryotic copper proteins that play essential roles in the generation of hormones/neurotransmitters; a detailed program is described that examines key regions of the protein in relation to the C-H and oxygen activation processes. The copper enzyme galactose oxidase (GalO), postulated to generate a similar Cu(II)-superoxo- intermediate, will be contrasted to T2M as a benchmark for understanding O-H vs. C-H activation. The 2-His, 1-Asp family of non-heme enzymes utilizes a common active site to functionalize a wide range of disparate reactions. Studies are described to examine two members of this family that depend on different reductants; ascorbate in the 1-aminocyclopropane 1- carboxylate oxidase (ACCO) reaction and alpha-ketoglutarate in the taurine dioxygenase (TauD) reaction. TauD is targeted for detailed studies of tunneling, while studies of ACCO will focus on the enigmatic pathway for ACC breakdown and its link to oxygen activation. Finally, two enzyme systems that catalyze removal of a charged hydrogen species as a proton, catalyzed by copper amine oxidase (CAO), and as a hydride ion, catalyzed by glucose oxidase (GO), provide unique opportunities to interrogate the inter- relationship between substrate specificity (CAO) and reaction driving force (GO) in the tunneling process. The above studies are of fundamental significance to our understanding of Nature's catalysts, with previously published findings from this laboratory leading to paradigm shifts regarding the physical origins of enzyme catalysis. Understanding the latter provides guidelines for the synthesis of small biomimetic catalysts, for the design of novel protein/peptide based catalysts and for the establishment of conceptual platforms that guide drug design. PUBLIC HEALTH RELEVANCE Two of the most fundamental processes that underlie aerobic life are C-H and O2 activation. The goal of this application is to elucidate and codify the principles that govern enzyme activation of these reactions.

描述（由申请人提供）：本申请的总体目标是阐明控制酶催化的 C-H 和 O2 活化过程的原理。 C-H 活化（质子、氢化物和氢原子）的研究重点是了解量子力学氢转移的作用及其与蛋白质结构和动力学的联系。氧活化的研究针对的是对于氧物质的性质和/或导致产物形成的反应途径仍然特别神秘的反应。药理学上重要的酶脂氧合酶已成为旨在了解氢隧道在酶催化中的作用的研究的中心。未来的研究包括探索蛋白质运动及其与隧道事件的联系、高压对隧道效应的影响，以及与嗜温大豆脂氧合酶进行比较的嗜热同源物的表征。在脂氧合酶中，假设了氧在蛋白质的离散区域内的通道，该区域与底物结合袋正交。这将使用位点特异性诱变进行进一步测试。酪胺β-单加氧酶 (T2M) 是真核铜蛋白小家族的成员，在激素/神经递质的生成中发挥重要作用；描述了一个详细的程序，该程序检查与 C-H 和氧激活过程相关的蛋白质关键区域。铜酶半乳糖氧化酶 (GalO) 被假定生成类似的 Cu(II)-超氧中间体，将与 T2M 进行对比，作为了解 O-H 与 C-H 激活的基准。 2-His、1-Asp 家族非血红素酶利用共同的活性位点来实现各种不同反应的功能。研究描述了检查该家族中依赖不同还原剂的两个成员； 1-氨基环丙烷1-羧酸氧化酶 (ACCO) 反应中的抗坏血酸和牛磺酸双加氧酶 (TauD) 反应中的 α-酮戊二酸。 TauD 的目标是对隧道效应进行详细研究，而 ACCO 的研究将重点关注 ACC 分解的神秘途径及其与氧活化的联系。最后，两种酶系统可催化去除带电氢物种（由铜胺氧化酶（CAO）催化）作为质子，以及作为氢阴离子（由葡萄糖氧化酶（GO）催化），提供了独特的机会来探究两者之间的相互关系。隧道过程中的底物特异性（CAO）和反应驱动力（GO）。上述研究对于我们理解自然催化剂具有根本意义，该实验室之前发表的研究结果导致了酶催化物理起源的范式转变。了解后者为小型仿生催化剂的合成、新型蛋白质/肽催化剂的设计以及指导药物设计的概念平台的建立提供了指导。公共卫生相关性有氧生命的两个最基本的过程是 C-H 和 O2 激活。该应用的目标是阐明和整理控制这些反应的酶激活的原理。