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Metalloprotein Mechanisms of Redox Regulation and Catalysis

氧化还原调节和催化的金属蛋白机制

基本信息

批准号：
10472758
负责人：
Stephen Wiley Ragsdale
金额：
$ 65.29万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10472758
关键词：
Address Affect Anaerobic Bacteria Anions Area Biliverdine Binding Binding Proteins Biochemical Biological Biophysics Biotechnology Carbon Dioxide Catalysis Cells Chemicals Complex Coupling Crystallization Environment Enzymes Funding Gases Generations Grant Health Heme Homeostasis Human Industrialization Iron Laboratories Length Ligation Mercury Metabolic Metabolism Metalloproteins Metals Methane Methylation Microbe Molecular Chaperones Molecular Conformation Monitor Movement NADPH-Ferrihemoprotein Reductase Nuclear Receptors Oxidation-Reduction Pathway interactions Planet Earth Reaction Regulation Research Signaling Molecule Structure Sulfur Tail Toxic effect Wood material Work career catalyst circadian pacemaker cofactor heme oxygenase-2 methyl radical microbial novel protein degradation protein protein interaction sample fixation sensor success trafficking

项目摘要

Abstract for Metalloprotein Mechanisms of Redox Regulation and Catalysis This proposal covers the three R01 grants funding my laboratory and aims to fill gaps in understanding the mechanisms of crucial aspects of redox regulation and catalysis by metalloproteins from microbes to humans. Successful completion of this work will reveal novel mechanisms with broad significance to human health, the environment, and biotechnology. Our research integrates a wide variety of biological, biophysical, biochemical and computational approaches. In Project Area 1, we will extend recent discoveries of novel bioinorganic and enzymatic mechanisms of anaerobic microbial CO and CO2 fixation in the Wood-Ljungdahl pathway (WLP), proposed to have fueled the origin of live on earth. We will reveal the mechanisms of these ancient enzymes: their generation and use of CO as a substrate, formation of bioorganometallic catalytic intermediates, utilization of nucleophilic and paramagnetic metal centers as catalysts, requirement of large domain movements and an interprotein CO channel and recently identified alcove for CO binding and CO2 fixation. We will define how these unique features choreograph redox activation, substrate and partner protein binding, leading to biological transformation that chemists are trying to mimic to more rapidly and efficiently accomplish chemically challenging reactions, e.g., to sequester, activate and convert CO2, methane and syngas into industrially important chemical feedstocks and fuels. While I started my career studying the WLP, I have applied the same expertise to other important evolving problems of metabolic regulation in humans by CO and metals and of mercury toxicity. In Project Area 2, we propose to deliver important discoveries on how human metabolism, metal homeostasis and the circadian clock are regulated by heme regulatory motifs (HRMs), signaling molecules (CO and NO), and cellular heme levels and redox poise. Focusing on heme oxygenase-2 (HO2), we will explore crucial conformational changes between the core and tail of HO2 and how these movements control protein turnover, protein-protein interactions, and heme conversion to CO, biliverdin and Fe. We will explore the hypothesis that HO2 serves a dual function in the cell in controlling heme trafficking and turnover. We will monitor the dynamics and interactions of full length HO2 with its redox partner cytochrome P450 reductase and with its heme donor GAPDH and define mechanisms that regulate heme-controlled HO2 turnover. Following up on our finding that the nuclear receptor Rev-Erbb uses a novel mechanism of redox- chemical coupling to serve as a CO/NO sensor, we will address how redox and gas binding affect its structure, function, activity and its interactions with partners like NCoR1 and its heme chaperone. In Project Area 3, recent successes in purifying and crystallizing the active HgcAB complex and defining its unusual thiolate- coordinated B12 cofactor, enable our proposed studies of the mechanism of microbial mercury methylation. We will determine the HgcAB structure, the redox and ligation states of the metal centers during catalysis, and whether a methyl radical or anion is used by these B12 and iron-sulfur clusters during catalysis.

金属蛋白氧化还原调控与催化机制研究