Defining the mechanistic determinants of catalytic bias in cofactor-based enzymatic oxidation-reduction reactions

定义基于辅因子的酶促氧化还原反应中催化偏差的机械决定因素

• 批准号: 10034848
• 负责人: JOHN W PETERS
• 金额: $ 36.72万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10034848
• 关键词: Acceleration; Active Sites; Adopted; Amino Acid Substitution; Automobile Driving; Biochemical; Biochemical Process; Biochemical Reaction; Biological Assay; Biological Models; Biophysics; Catalysis; Cell physiology; Cells; Characteristics; Electrons; Electrostatics; Energy Metabolism; Environment; Enzymes; Exhibits; Foundations; Gene Fusion; Goals; Health; Human; Hydrogen; Hydrogenase; Lead; Life; Metabolic Control; Metabolism; Metals; Mission; Modeling; Modification; Molecular; Molecular Conformation; Movement; Outcome; Oxidation-Reduction; Property; Proteins; Protons; Reaction; Research; Resources; Roentgen Rays; Role; Site; Site-Directed Mutagenesis; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Structure; System; Testing; Thermodynamics; United States National Institutes of Health; Work; base; catalyst; chemical reaction; cofactor; drug development; experimental study; improved; innovation; oxidation; physical property; targeted treatment; Acceleration; Active Sites; Adopted; Amino Acid Substitution; Automobile Driving; Biochemical; Biochemical Process; Biochemical Reaction; Biological Assay; Biological Models; Biophysics; Catalysis; Cell physiology; Cells; Characteristics; Electrons; Electrostatics; Energy Metabolism; Environment; Enzymes; Exhibits; Foundations; Gene Fusion; Goals; Health; Human; Hydrogen; Hydrogenase; Lead; Life; Metabolic Control; Metabolism; Metals; Mission; Modeling; Modification; Molecular; Molecular Conformation; Movement; Outcome; Oxidation-Reduction; Property; Proteins; Protons; Reaction; Research; Resources; Roentgen Rays; Role; Site; Site-Directed Mutagenesis; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Structure; System; Testing; Thermodynamics; United States National Institutes of Health; Work; base; catalyst; chemical reaction; cofactor; drug development; experimental study; improved; innovation; oxidation; physical property; targeted treatment

PROJECT SUMMARY Enzymatic reactions comprise the basic building blocks essential to the biochemical processes of cellular metabolism. While most enzymatic reactions are reversible, certain enzymes accelerate a reaction in one direction significantly differently than the reverse direction. The mechanistic determinants of this phenomenon – often referred to as “catalytic bias” – are generally unknown. Our long-term goal of this project is to identify the fundamental principles adopted by redox enzymes (enzymes involved in oxidation-reduction reactions) that provide molecular level control of the catalytic bias. In doing so, we will provide a greater fundamental understanding of the factors that control metabolic processes in all life. Specifically, the objective of this proposal is to delineate determinants that influence the directional reactivity of model Fe containing hydrogenases that are structurally related but exhibit large differences in catalytic bias for the specific reversible hydrogen (H2) oxidation reaction from electron and protons. The central hypothesis is that catalytic bias commonly in redox enzymes results from the relative differential stabilization and destabilization of oxidation states of the respective redox cofactors critical to determining the rate limiting step of the catalytic cycle. The rationale underlying the proposal is that the implementation will result in defining mechanistic determinants of the proposed model system. The proposed work will culminate in elucidating universal, mechanistic factors of catalytic bias that govern a large number of, if not all, redox enzymes. The central hypothesis will be tested by pursuing three specific aims that examine how 1) the reduction potential of the active site proximal accessory redox clusters; 2) the characteristics of the active site cluster protein environment; and 3) the secondary coordination sphere structural dynamics can control reactivity and catalytic bias in cofactor-based oxidation reduction catalysis. To pursue these aims, we will employ an innovative strategy integrating biochemical, structural, spectroscopic, and computational approaches on a unique, one-of-a-kind model hydrogenase platform. The proposed research is significant, because it will delineate molecular determinants that influence the fine-tuning of redox cofactors through the relative stabilization or destabilization of oxidation states to afford certain reactivity fundamental to directing energy and matter in cells. The work will provide additional foundational resources in the form of a blueprint for integrating multiple biophysical and computational approaches.

项目摘要 酶促反应包括对细胞生化过程必不可少的基本构建块 代谢。虽然大多数酶促反应是可逆的，但某些酶在一个反应​​中加速了反应 方向明显不同于反向方向。这种现象的机械决定剂 - 通常被称为“催化偏见” - 通常未知。我们的长期目标是确定 氧化还原酶采用的基本原理（涉及氧化还原反应的酶） 提供催化偏置的分子水平控制。这样，我们将提供更大的基本 了解控制所有生命中代谢过程的因素。具体而言，该提议的目的 是要描绘的确定会影响含有Fe的模型Fe的定向反应性，该模型含有氢化酶 在结构上相关，但暴露于特定可逆氢的催化偏置差异很大（H2） 电子和质子的氧化反应。中心假设是氧化还原中通常 酶是由相对氧化态的相对差异稳定和不稳定的酶导致的 氧化还原辅助因子对于确定催化循环的速率限制步骤至关重要。基础的基本原理 建议是实施将导致定义所提出模型的机械决定因素 系统。拟议的工作将达到阐明催化偏见的通用机械因素 控制大量（如果不是全部）氧化还原酶。中心假设将通过追求三个 具体目的是检查如何）如何）活性位点代理辅助氧化还原簇的降低潜力； 2） 活性位点簇蛋白环境的特征； 3）次级协调领域 结构动力学可以控制基于辅助因子的氧化还原催化中的反应性和催化偏置。到 追求这些目标，我们将采用一项创新战略，将生化，结构，光谱型和 在独特的，独一无二的模型氢化酶平台上采用计算方法。拟议的研究是 显着，因为它将描绘影响氧化还原辅助因子微调的分子确定词 通过氧化态的相对稳定或不稳定，以提供一定的反应性 指导细胞中的能量和物质。这项工作将以A的形式提供其他基础资源 用于整合多种生物物理和计算方法的蓝图。