Principles of C-H and O2 Activation

描述（由申请人提供）：本申请的首要目的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）的研究集中在理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。氧活化的研究是针对那些在氧物种的性质和/或导致产物形成的反应途径方面仍然特别神秘的反应。重要的酶脂氧合酶已成为一个中心针的研究，旨在了解氢隧道在酶催化的作用，未来的研究包括探针的蛋白质运动和他们的联系的隧道事件，高压隧道的影响，和表征的嗜热同系物比较嗜温大豆脂氧合酶。在脂肪氧合酶中，氧在蛋白质的离散区域内的通道，与底物结合口袋正交，已经被假定;这将使用位点特异性诱变进一步测试。酪胺？单加氧酶（T2 M）是真核细胞铜蛋白的一个小家族的成员，在激素/神经递质的产生中发挥重要作用;描述了一个详细的程序，检查与C-H和氧活化过程有关的蛋白质的关键区域。铜酶半乳糖氧化酶（GalO），假定产生类似的Cu（II）-超氧-中间体，将对比T2 M作为基准，了解O-H与C-H激活。非血红素酶的2-His，1-Asp家族利用共同的活性位点来官能化广泛的不同反应。研究被描述为检查这个家庭的两个成员，依赖于不同的还原剂;抗坏血酸在1-氨基环丙烷1-羧酸氧化酶（ACCO）反应和α-酮戊二酸在牛磺酸双加氧酶（TauD）反应。TauD是针对隧道的详细研究，而ACCO的研究将集中在ACC分解的神秘途径及其与氧活化的联系。最后，催化去除作为质子的由铜胺氧化酶（CAO）催化的带电氢物质和作为氢化物离子的由葡萄糖氧化酶（GO）催化的带电氢物质的两种酶系统提供了询问隧穿过程中底物特异性（CAO）和反应驱动力（GO）之间的相互关系的独特机会。上述研究对我们理解自然界的催化剂具有根本意义，该实验室先前发表的研究结果导致了关于酶催化的物理起源的范式转变。了解后者提供了小的仿生催化剂的合成，新的蛋白质/肽为基础的催化剂的设计和指导药物设计的概念平台的建立的指导方针。 有氧生活的两个最基本的过程是C-H和O2激活。本申请的目的是阐明和编纂这些反应的酶激活的原则。

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.