Drug-Mediated Alteration of Cytochrome P450

药物介导的细胞色素 P450 改变

• 批准号: 7619167
• 负责人: YOICHI OSAWA
• 金额: $ 34.49万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7619167
• 关键词: Address; Adverse drug effect; Adverse effects; Aryl Hydrocarbon Hydroxylases; Binding; Biological; Biological Process; Cells; Chemicals; Chemistry; Cleaved cell; Client; Clinical Trials; Cytochrome P450; Cytochromes; Decision Making; Drug toxicity; Enzymes; Functional disorder; Gastrointestinal Motility; Gastrointestinal tract structure; Guanabenz; Heme; Hemeproteins; Injury; Knockout Mice; Knowledge; Laboratories; Lead; Ligands; Liver; Mass Spectrum Analysis; Mediating; Metabolic; Metabolism; Modeling; Molecular; Molecular Chaperones; Nature; Nitric Oxide Synthase; Oxygen; Pathway interactions; Patients; Peristalsis; Pharmaceutical Preparations; Physiological Processes; Play; Process; Prosthesis; Proteins; Quality Control; Reaction; Regulation; Research; Research Personnel; Role; Safety; Scheme; System; Talents; Techniques; Time; Triage; Work; Xenobiotics; aminoguanidine; base; crosslink; design; drug mechanism; drug metabolism; enzyme pathway; experience; inhibitor/antagonist; programs; protein degradation; reconstitution; repaired; response; tool; ubiquitin ligase

DESCRIPTION (provided by applicant): The long-term objective of the proposed research is to elucidate the mechanisms of drug- and xenobiotic- mediated inactivation, degradation, and turnover of cytochrome P450 enzymes. Nitric oxide synthase (NOS), the most highly regulated cytochrome P450 enzyme, plays a key role in a variety of biological processes, including regulation of gastrointestinal motility and liver drug metabolism. The inactivation of NOS by drugs, such as guanabenz and aminoguanidine, involves the metabolic formation of reactive drug and oxygen intermediates. Our approach is to first characterize the disposition, in particular, the metabolism of the drug and related xenobiotics by NOS with the use of analytical techniques such as LC-MS/MS. We will then study how the metabolites, especially those bound to heme and protein, enhance the proteasomal degradation of the drug-altered enzyme. We have also discovered that cellular factors facilitate the insertion of heme into heme-deficient apo-NOS and we postulate that this may be a repair mechanism for metabolite- inactivated NOS. Thus, in order to understand how drug metabolism by NOS can cause adverse drug effects we propose the following specific aims: (1) To characterize the mechanism of drug-mediated inactivation of NOS. (2) To characterize what forms of inactivated and dysfunctional NOS are recognized for ubiquitylation and proteasomal degradation. (3) To characterize the heme insertion process into heme- deficient apo-NOS that is facilitated by cellular protein factors. The completion of these studies will define the chemistry of how drugs are metabolized by NOS and lead to NOS inactivation. We will show how these molecular interactions lead to defined and predictable biological responses that ultimately define the pharmacological and toxicological profiles of certain drugs. This will aid in the design of safe and effective drugs to control NOS as well as strategies to decrease adverse drug effects related to NOS. We also address the fundamental biological processes of how the heme prosthetic group is inserted into P450 NOS and how cells maintain NOS protein quality control. Overall, this work furthers our understanding of how the metabolism of drugs, especially those used chronically, can alter the normal biological processes to give rise to adverse as well as beneficial drug effects. Ultimately, these studies may provide a way to predict, evaluate, and refine, the efficacy and safety of drugs and other xenobiotics.

描述（由申请人提供）：拟议研究的长期目标是阐明药物和外源介导的细胞色素P450酶失活、降解和转化的机制。一氧化氮合酶（NOS）是调控程度最高的细胞色素P450酶，在多种生物过程中发挥关键作用，包括调节胃肠道运动和肝脏药物代谢。胍苯和氨基胍等药物对NOS的失活涉及活性药物和氧中间体的代谢形成。我们的方法是首先利用LC-MS/MS等分析技术，通过NOS表征药物的处置，特别是药物和相关外源物的代谢。然后，我们将研究代谢物，特别是与血红素和蛋白质结合的代谢物，如何增强药物改变酶的蛋白酶体降解。我们还发现细胞因子促进血红素插入血红素缺乏的载脂蛋白NOS，我们假设这可能是代谢物失活NOS的修复机制。因此，为了了解NOS的药物代谢如何引起药物不良反应，我们提出以下具体目标：(1)表征药物介导NOS失活的机制。(2)表征哪些形式的失活和功能失调的NOS被泛素化和蛋白酶体降解所识别。(3)表征细胞蛋白因子促进血红素插入到缺乏血红素的载脂蛋白nos中的过程。这些研究的完成将确定药物如何被NOS代谢并导致NOS失活的化学过程。我们将展示这些分子相互作用如何导致确定的和可预测的生物反应，最终确定某些药物的药理学和毒理学特征。这将有助于设计安全有效的药物来控制NOS，以及减少与NOS相关的药物不良反应的策略。我们还讨论了血红素假体如何插入P450 NOS以及细胞如何维持NOS蛋白质量控制的基本生物学过程。总的来说，这项工作进一步加深了我们对药物代谢的理解，特别是那些长期使用的药物，如何改变正常的生物过程，从而产生有害和有益的药物作用。最终，这些研究可能提供一种方法来预测、评估和改进药物和其他外源性药物的有效性和安全性。