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Redox enzymes - tuning and design

氧化还原酶 - 调整和设计

基本信息

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
项目类别：
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

项目摘要

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.

项目总结/文摘