MODEL SYSTEMS FOR FLAVOENZYME ACTIVITY

黄酶活性模型系统

• 批准号: 2828638
• 负责人: VINCENT M. ROTELLO
• 金额: $ 17.97万
• 依托单位: UNIVERSITY OF MASSACHUSETTS AMHERST
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2828638
• 关键词: chemical models; computer simulation; dipole moment; electrochemistry; electron nuclear double resonance spectroscopy; electron spin resonance spectroscopy; electronic spectra; enzyme activity; enzyme mechanism; enzyme model; enzyme substrate; flavins; flavodoxin; flavoproteins; hydrogen bond; ionic bond; model design /development; molecular dynamics; nuclear magnetic resonance spectroscopy; oxidation reduction reaction; oxidoreductase

Flavoenzymes are proteins that use the flavin co-factor (FAD or FMN) to effect redox transformations and electron transfer. These enzymes function in a variety of essential biological roles, including metabolism, biosynthesis, and electron transport. The diversity of processes catalyzed by these protein is equally impressive, encompassing such divergent transformations such as thiol and amine oxidations, aromatic hydroxylation, and fatty acid dehydrogenation. In previous research, we have used model systems to explore fundamental aspects of flavoenzyme function, in particular the role of enzyme-co-factor interactions in modulating flavin redox processes. These models have allowed us to isolate and quantify specific interactions, and establish their role in determining flavoenzyme function. In our proposed research, we will extend these studies, using a synergistic application of synthetic receptors with chemical, electrochemical, spectroscopic and computational techniques. In chemical studies, we will synthesize receptors to explore the role of recognition processes in the mechanisms and energetics of the biomedically crucial thiol dehydrogenases. Concurrently, we will exploit the ability of electrochemical techniques to directly quantify the energetics of redox processes. In these investigations, we will synthesize receptors to determine the role of "traditional" non-covalent interactions, including hydrogen bonding, in the modulation of flavin redox processes. We will also create receptors to ascertain the role of micro- and macroscopic dipoles on flavin redox processes. These investigations, while focusing on the flavin redox system, will also provide insight into the general issue of the function of electrostatics in enzyme function. Spectroscopically, we will use a two-pronged approach to the study of flavin species. First, we will investigate the effects of recognition on the NMR, EPR and ENDOR spectra of flavins and flavin radicals. We will then use these spectra as calibration for computational methodology. From the synergy of these two methods, we will be able to quantify the effects of individual interactions on fundamental properties, including charge and spin density distributions. Using our model systems as a benchmark, we will also be able to extend with confidence our computational studies to actual enzymatic systems.

黄素酶是一种利用黄素辅因子(FAD或FMN)来 影响氧化还原转换和电子转移。这些酶 在各种基本的生物角色中发挥作用，包括 新陈代谢、生物合成和电子传输。的多样性 由这些蛋白质催化的过程同样令人印象深刻，包括 这种发散转化，例如硫醇和胺氧化， 芳香族羟基化和脂肪酸脱氢。在以前的 研究中，我们使用模型系统来探索以下基本方面 黄素酶的功能，特别是酶-辅因子的作用 黄素氧化还原过程中的相互作用。这些型号有 使我们能够隔离和量化特定的交互作用，并建立 它们在确定黄素酶功能中的作用。 在我们提议的研究中，我们将使用一个 合成受体与化学物质的协同应用， 电化学、光谱和计算技术。在化学领域 在研究中，我们将合成受体来探索识别作用 在生物医学上至关重要的机制和能量学的过程 硫醇脱氢酶。同时，我们将利用 直接量化氧化还原能量的电化学技术 流程。在这些研究中，我们将合成受体来 确定“传统”非共价相互作用的作用，包括 氢键，在黄素氧化还原过程的调制中。我们会 也创造受体来确定微观和宏观的作用 黄素氧化还原过程中的偶极子。这些调查，在专注于 关于黄素氧化还原系统，也将提供一般洞察 静电在酶功能中的作用问题。 在光谱方面，我们将使用双管齐下的方法来研究 黄素物种。首先，我们将研究认知对认知的影响 黄素和黄素自由基的核磁共振、电子顺磁共振和恩多尔谱。我们会 然后使用这些光谱作为计算方法的校准。 通过这两种方法的协同作用，我们将能够量化 个人相互作用对基本属性的影响，包括 电荷和自旋密度分布。使用我们的模型系统作为 基准，我们也将能够满怀信心地扩展我们的 对实际酶系统的计算研究。