Natural engineering of multi-electron biological oxidation & reduction

细胞活动及其调控的能量基础依赖于体内一系列氧化还原酶蛋白。 生物氧化还原代谢和呼吸膜能量转换。这个 底物氧化还原和能量转换的多个催化位的机理，特别是在 线粒体！呼吸，已被证明很难通过实验获得，因为自然的复杂性和 脆弱。人们仍然对它们知之甚少。我们的提案旨在揭示氧化还原的自然工程-- 多电子辅因子和底物在这些位置上的耦合质子交换和转移 氧化还原。我们的方法建立在我们的蛋白质电子隧道工程指南的基础上， 在上一次赠款期间得到了加强，以使从头设计和组装简单而坚固的阿尔法- 用于多电子催化的以蛋白质为基础的模型和模板的螺旋蛋白质。 模型将被设计成提供最简单的水溶性或跨膜结构，能够 捕捉天然氧化还原中心的功能特性。它们的简单性和适应性使我们能够 调查呼吸链中仍未解决的催化功能问题。Maquettes将是 在溶液和电极上用光和电测法激活，一步步地解剖 电子转移和质子交换的热力学和动力学。Maquettes将整合所有密钥 双电子、多质子辅因子/底物苯醌、烟酰胺和黄素，以及两和四- 电子衬底O2。我们的定位是专注于可逆能量转换催化的问题 细胞色素BD的QO位对苯二酚的作用机理研究 医学上有害的短路和激进的产生。我们将扩展我们创造的稳定氧气的模型 亚铁血红素状态，以考察两电子和四电子氧还原以及生理上重要的两电子和四电子氧还原. NO和H_2O_2的电子化学有了稳定和适应性强的模型，我们可以开发生理 化学在开发纳米级设备中的作用。 人类通过氧气呼吸分解食物会产生健康生活所需的全部能量。 是细胞调节的核心部分。氧自由基有稳定缓慢的释放是正常的 随着时间的推移，这会导致细胞损伤、衰老和疾病。在压力下，在许多手术中 程序中爆发的自由基可能会加速这些有害的过程。关于这笔赠款的研究 描述了一种新的方法来理解健康的氧化能量供应和控制的基本过程，如 以及有害的激进一代。随着进步，我们将更好地预测和跟踪疾病的发生 并采取行动减缓或逆转它。

The energetic foundation of cellular activity and its regulation relies on a string of oxidoreductase proteins in biological oxidative and reductive metabolism and respiratory membrane energy conversion. The mechanisms of many catalytic sites of substrate oxidation-reduction and energy conversion, particularly in mitochondria! respiration, have proven to be difficult to access experimentally due to natural complexity and fragility. They remain poorly understood. Our proposal aims to reveal the natural engineering of the redox- coupled proton exchange and transfer operating at these sites of multi-electron cofactor and substrate oxidation-reduction. Our approach builds on our engineering guidelines for protein electron tunneling, strengthened in the last grant period, to inform the de novo design and assembly of simple and robust alpha- helical proteins intended to serve as protein-based models, maquettes, for multi-electron catalysis. Maquettes will be designed to provide the simplest water-soluble or trans-membrane structures that can capture the functional properties of natural redox centers. Their simplicity and adaptability allow us to investigate catalytic functional problems that remain unsolved in the respiratory chain. Maquettes will be activated with light and electrometric methods in solution and on electrodes to dissect step-by-step the thermodynamics and kinetics of electron transfer and proton exchange. Maquettes will incorporate all key two-electron, multi-proton cofactors/substrates quinone, nicotinamide and flavin, and the two-and four- electron substrate O2. We are positioned to focus on the problem of reversible energy conversion catalysis of hydroquinone-quinone in the Qo site of the cytochrome bd aiming to determine the mechanistic root of medically harmful short-circuits and radical generation. We will extend our maquette creation of a stable O2 ferrous heme state, to examine two- and four-electron O2 reduction and the physiologically important two- electron chemistries of NO and H2O2. With stable and adaptable maquettes, we can exploit physiological chemistry in the development of nanoscale devices. The breakdown of food by oxygen respiration in humans produces all the energy needed for a healthy life and is a central part of cellular regulation. It is normal that there is a steady slow release of oxygen radicals that over time cause cellular damage, aging and disease. Under stress, and in during many surgical procedures bursts of radicals can accelerate these deleterious processes. The research of this grant describes a new way to understand the processes underlying healthy oxidative energy supply and control as well as deleterious radical generation. With progress we will be better predict and track the onset of disease and act to slow it or reverse it.