Redox enzymes - tuning and design

氧化还原酶 - 调整和设计

• 批准号: 10437246
• 负责人: ANASTASSIA N ALEXANDROVA
• 金额: $ 11.05万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10437246
• 关键词: 3-Dimensional; Aerobic; Affect; Alkenes; Area; Behavior; Binding; Biochemical; Bioinorganic Chemistry; Biotin; Catalysis; Cations; Cell Respiration; Chemistry; Complex; Electrochemistry; Electron Transport; Electrostatics; Enzymatic Biochemistry; Enzymes; Funding; Goals; Human; Hybrids; Hydrogen Bonding; Hydrophobicity; Individual; Ions; Iron; Learning; Ligands; Link; Measurement; Measures; Mechanics; Mediating; Metal Binding Site; Metalloproteins; Metals; Modification; Mutagenesis; Mutation; Nature; Organism; Oxidation-Reduction; Oxides; Oxygen; Peroxides; Phosphines; Physiological; Process; Property; Proteins; Proxy; Reaction; Reactive Oxygen Species; Research; Route; Site; Site-Directed Mutagenesis; Streptavidin; Sulfides; Sulfur; Superoxides; Synthesis Chemistry; System; Technology; Theoretical model; United States National Institutes of Health; cofactor; cupredoxin; design; electric field; enzyme activity; experimental study; interest; metalloenzyme; oxidation; protein structure; quantum; response; salen; simulation; stem; tool

Project Summary/Abstract Enzymatic redox catalysis, imperative to all organisms, is a showcase of nature's mastery in tuning the activity and selectivity at the electronic level. The reduction potential, E0, of the metal performing the redox transformation is precisely controlled beyond the primary coordination sphere through the microenvironment of the metal in the protein. Interactions of consequence for the physiologically relevant modulations of E0 are often weak; they include hydrogen bonds, hydrophobic contacts, and long- to intermediate-range electrostatics. It is a challenge to study the impact of these individual factors on metalloenzymatic redox processes, and even more so to design metalloproteins that would perform selective redox catalysis. We propose an approach that allows elaboration of the individual factors that govern redox properties of metalloproteins en route to the design artificial Co and Mn metalloenzymes with selective oxygen reduction or oxidative reactivity. We propose metalloprotein constructs that combine synthetic redox active complexes of Co and Mn with salen ligands, and the protein streptavidin (Sav) to which biotinylated organometallic complexes will be attached. In these systems, the intermediate-range electrostatics will be controlled largely within the organometallic complex that has a unique feature, a secondary metal binding site containing a redox innocent metal ion exerting an electric field on the active cation. Electrochemistry and reactivity of these complexes will be measured and computed. The protein matrix of Sav will be used for incorporating other weak interactions in the microenvironment of the metal, such as H-bonds and hydrophobic contacts, through mutagenesis. Mixed quantum mechanical and quantum-classical simulations will guide the choice for mutations to consider for the desired redox activity. Importantly, while in natural metalloenzymes all the weak factors influencing E0 also influence the protein structure and couple to each other, in the proposed systems, they are decoupled to the extent possible, and thus more amendable to studying and strategic modifications. Broadly, this research will allow learning how redox chemistry is controlled in nature, and how to approach the design of redox enzymes. Our target catalytic reactions of oxygen reduction and aerobic substrate oxidation are of interest to both natural enzymology and the broader field of catalysis, and understanding these reactions is essential for realizing how aerobic metabolism efficiently utilizes oxygen while avoiding the formation deleterious concentrations of ROS.

项目概要/摘要 酶氧化还原催化对所有生物体来说都是必不可少的，它展示了大自然在调节活性和 电子水平的选择性。进行氧化还原转变的金属的还原电位 E0 为 通过金属的微环境在主配位层之外进行精确控制 蛋白质。 E0 的生理相关调节的相互作用通常较弱；他们包括 氢键、疏水接触和长程到中程静电。研究这个问题是一个挑战 这些单独因素对金属酶氧化还原过程的影响，对于设计金属蛋白更是如此 它将进行选择性氧化还原催化。我们提出了一种允许详细阐述个人的方法 设计人工钴和锰金属酶过程中控制金属蛋白氧化还原特性的因素 具有选择性氧还原或氧化反应性。我们提出了结合合成的金属蛋白结构 Co 和 Mn 与 salen 配体的氧化还原活性复合物，以及生物素化的蛋白链霉亲和素 (Sav) 将附着有机金属配合物。在这些系统中，中程静电将受到控制 主要在有机金属络合物中，该络合物具有独特的特征，即含有次要金属结合位点的 氧化还原无害金属离子对活性阳离子施加电场。这些的电化学和反应性 将测量和计算复合物。 Sav 的蛋白质基质将用于掺入其他弱 通过诱变，金属微环境中的相互作用，例如氢键和疏水接触。 混合量子力学和量子经典模拟将指导要考虑的突变的选择 所需的氧化还原活性。重要的是，在天然金属酶中，影响 E0 的所有弱因素也 影响蛋白质结构并相互耦合，在所提出的系统中，它们在一定程度上解耦 可能，因此更适合研究和战略修改。总的来说，这项研究将使学习 自然界如何控制氧化还原化学，以及如何设计氧化还原酶。我们的目标催化 氧还原反应和需氧底物氧化反应对于天然酶学和微生物学都很感兴趣。 更广泛的催化领域，了解这些反应对于了解有氧代谢如何进行至关重要 有效利用氧气，同时避免形成有害浓度的活性氧。