Microsomal Cytochromes P450 and their Interactions with their Redox Partners

微粒体细胞色素 P450 及其与氧化还原伙伴的相互作用

• 批准号: 8244399
• 负责人: LUCY A WASKELL
• 金额: $ 35.55万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8244399
• 关键词: Active Sites; Address; Alanine; Anabolism; Bile Acids; Binding; Binding Sites; Biochemical; Blood Clot; Blood coagulation; Carcinogens; Cardiovascular system; Catalysis; Chemicals; Cholesterol; Clinical; Collaborations; Complex; Cytochrome P450; Cytochromes b5; Development; Drug Interactions; Drug usage; Eicosanoids; Electron Nuclear Double Resonance; Electronics; Electrons; Environmental Pollution; Enzymes; Estrogens; Flavin Mononucleotide; Freezing; Goals; High Pressure Liquid Chromatography; Human; Human Activities; Hydrocortisone; Hydroquinones; In Vitro; Individual; Investigation; Isoenzymes; Knowledge; LGLA; Laboratories; Length; Life; Light; Lipids; Lyase; Mass Spectrum Analysis; Measures; Mechanics; Mediating; Membrane; Metabolism; Mixed Function Oxygenases; Modeling; Molecular; Molecular Conformation; Mothers; Mutagenesis; Mutate; NADPH-Ferrihemoprotein Reductase; Nature; Organ; Organism; Oxidation-Reduction; Oxidoreductase; Pharmaceutical Preparations; Physiological Processes; Plants; Polychlorinated Biphenyls; Procedures; Prodrugs; Property; Proteins; Psychotropic Drugs; Reaction; Regulation; Research Personnel; Route; Series; Site-Directed Mutagenesis; Steroids; Substrate Specificity; Surface; Techniques; Testing; Testosterone; Therapeutic Agents; Toxic effect; Vitamin D; Xenobiotics; base; bisphenol A; chemotherapeutic agent; cytochrome b5 reductase; design; drug metabolism; environmental agent; flavin mononucleotide semiquinone; human tissue; hydroquinone; in vivo; insight; member; membrane activity; mutant; novel; phthalates; public health relevance; quantum; research study

DESCRIPTION (provided by applicant): The cytochrome P450 (cyt P450) superfamily consists of more than 11,000 members. They are ubiquitous, being found in all kingdoms of living organisms and plants and are referred to as Mother Nature's blowtorch, due to their ability to oxidize a vast number of stable chemical entities. Humans possess 56 different cyts P450, many of which are essential for early development and life itself. Other human cyts P450 determine the toxicity, duration of action, and elimination of the vast majority of therapeutic agents, carcinogens, and environmental agents to which humans are exposed. Xenobiotic metabolizing cyts P450 are also responsible for the majority of drug-drug interactions and adverse drug reactions. A third group of cyts P450 are responsible for the biosynthesis or metabolism of essential endogenous compounds. This includes virtually all steroids (cholesterol, bile acids, estrogens, testosterone, cortisol, and vitamin D) and many lipids and eicosanoids. Cyts P450 exists in virtually every organ and tissue of humans. The cyts P450 are not self-sufficient but rather require interactions with other proteins in order to function. Cyt P450 reductase and cytochrome b5 (cyt b5), which provide electrons to cyt P450, are two proteins that support the activity of cyt P450. The long-term goal of this project is to understand the structural and mechanistic basis for the regulation of the activity of the membrane-bound microsomal cyts P450 by its redox partners, cyt P450 reductase and cyt b5. The short-term goals of this proposal, using both human and model cyts P450, are to understand the biochemical basis of how the redox partners of cyt P450 regulate its activity, substrate specificity, and catalytic mechanism. Experimental techniques, including site-directed mutagenesis, rapid quenching of cyt P450 activity by chemical means, and freezing, HPLC-mass spectrometry, and quantum mechanical/molecular mechanical calculations will be employed to elucidate how the activity of microsomal cyts P450 is regulated by its redox partners. Understanding how nature designs cyt P450 active sites is a fundamental question with implications for predicting and eventually modifying the routes of metabolism of a large number of environmental contaminants such as phthalates, bisphenol A, polychlorinated biphenyls (PCBs) and many currently used drugs, including chemotherapeutic agents, psychoactive compounds, and cardiovascular therapies. Knowledge of the molecular mechanism by which the activity of human cyts P450 can be regulated will also prove to be a tremendous asset in developing drugs and procedures to alter the large number of critical physiologic processes in which the human cyts P450 participate, as well as in designing less toxic and more specific therapeutic agents and prodrugs, especially chemotherapeutic agents and environmental contaminants. PUBLIC HEALTH RELEVANCE: The proposed investigation of how the human enzymes responsible for drug metabolism, drug-drug interactions, blood clotting, and cholesterol levels function at a molecular level will provide new information that will prove to be an asset 1) in developing novel procedures to alter the large number of physiologic processes in which the 56 human cyts P450 participate and 2) in designing and synthesizing less toxic and more specific therapeutic agents and prodrugs, especially chemotherapeutic agents, and "greener" environmental contaminants.

描述（由申请人提供）：细胞色素P450（cyt P450）超家族由超过11，000个成员组成。它们无处不在，存在于所有生物体和植物王国中，并被称为大自然的喷灯，因为它们能够氧化大量稳定的化学实体。人类拥有56种不同的细胞色素P450，其中许多对早期发育和生命本身至关重要。其他人类细胞P450决定毒性，作用持续时间，以及人类暴露的绝大多数治疗剂，致癌物和环境因子的消除。异源生物质代谢细胞P450也是大多数药物相互作用和药物不良反应的原因。第三组细胞P450负责必需内源性化合物的生物合成或代谢。这包括几乎所有的类固醇（胆固醇，胆汁酸，雌激素，睾酮，皮质醇和维生素D）和许多脂质和类花生酸。细胞色素P450几乎存在于人类的每个器官和组织中。 细胞色素P450不是自给自足的，而是需要与其他蛋白质相互作用才能发挥作用。细胞色素P450还原酶和细胞色素b5（cyt b5）为细胞色素P450提供电子，是支持细胞色素P450活性的两种蛋白质。该项目的长期目标是了解膜结合微粒体细胞P450通过其氧化还原伙伴cyt P450还原酶和cyt b5调节活性的结构和机制基础。 该提案的短期目标，使用人类和模型细胞色素P450，是了解细胞色素P450的氧化还原伙伴如何调节其活性，底物特异性和催化机制的生化基础。实验技术，包括定点诱变，快速淬火的细胞色素P450活性的化学手段，冷冻，高效液相色谱-质谱法，和量子力学/分子力学计算将被用来阐明微粒体细胞色素P450的活性是如何调节其氧化还原伙伴。了解自然界如何设计细胞色素P450活性位点是一个基本问题，它对预测和最终改变大量环境污染物的代谢途径有影响，这些污染物包括邻苯二甲酸酯、双酚A、多氯联苯（PCB）和许多目前使用的药物，包括化疗药物、精神活性化合物和心血管治疗药物。人细胞P450活性可被调节的分子机制的知识也将被证明是一个巨大的资产，在开发药物和程序，以改变大量的关键生理过程中，人细胞P450参与，以及在设计毒性较小和更具体的治疗剂和前药，特别是化疗剂和环境污染物。 公共卫生相关性：拟议的研究如何人类酶负责药物代谢，药物相互作用，血液凝固，和胆固醇水平在分子水平上的功能将提供新的信息，这些信息将被证明是一种资产：1）开发新的程序来改变56个人类细胞P450参与的大量生理过程; 2）在设计和合成毒性更小和更特异性的治疗剂和前药，特别是化学治疗剂和“绿色”环境污染物方面。