Mechanism-based Inhibition of P450 2D6 by a Piperazine-containing Compound

含哌嗪化合物对 P450 2D6 的基于机制的抑制

• 批准号: 7880277
• 负责人: LAURA L FURGE
• 金额: $ 12.39万
• 依托单位: KALAMAZOO COLLEGE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7880277
• 关键词: Acetylene; Active Sites; Alkenes; Amino Acids; Apoproteins; Binding; Biochemistry; Camphor 5-Monooxygenase; Carcinogens; Cessation of life; Complex; Cytochrome P450; Docking; Dopamine Agonists; Drug Design; Drug Interactions; Educational process of instructing; Elderly; Enzymes; Event; Family; Family member; Fostering; Future; Goals; Health; Heme; Hemeproteins; High Pressure Liquid Chromatography; Human; Human Genome; Individual; Individual Differences; Knowledge; Label; Laboratories; Lead; Liver; Mass Spectrum Analysis; Medical; Medicine; Metabolism; Methods; Mind; Modeling; Molecular Models; Nature; Pathway interactions; Pharmaceutical Preparations; Pharmacologic Substance; Piperazines; Plant alkaloid; Protein Isoforms; Proteins; Reaction; Recombinants; Research; Role; Side; Steroids; Structure; Students; Substrate Specificity; Vitamins; Work; Xenobiotics; adduct; base; crosslink; design; detoxication; drug metabolism; enzyme activity; enzyme mechanism; functional group; gel electrophoresis; inhibitor/antagonist; insight; interest; molecular modeling; public health relevance; reconstruction; research study; response; small molecule; steroid metabolism; success; tool

DESCRIPTION (provided by applicant): Cytochrome P450 enzymes in humans are a family of heme-containing enzymes involved in metabolism of steroids, vitamins, eiconsanoids, and xenobiotics such as drugs, complex plant alkaloids, carcinogens, and other small molecules. With the sequencing of the human genome, fifty-seven family members have been identified. The role of P450s in metabolism of nearly all drugs has made this family of enzymes of considerable interest in medicine and for human health. While only about a dozen P450s are involved in drug metabolism, they are able to metabolize hundreds of thousands of compounds. One caveat of such broad substrate specificity among drug metabolizing P450 enzymes is that the enzymes are also susceptible to inhibition by products of their own reactions. This type of inhibition is called mechanism-based inhibition and leads to irreversible inactivation of the enzyme. Compounds that act as mechanism-based inhibitors are important tools for understanding structure/function of these enzymes. Because they become covalently attached to their enzyme targets, mechanism-based inhibitors can aid in identification of important amino acid side chains in the enzyme mechanism. Also, understanding of pathways and drug functional groups involved in mechanism-based inhibition can aid in rational design of future drugs. The overall goal of this research is to understand mechanisms of P450 irreversible inhibition by different compounds. One important drug-metabolizing enzyme is P450 2D6. While constituting less than 5% of the total liver P450, the enzyme is responsible for metabolism of ~25% of pharmaceutical compounds. The enzyme also displays multiple polymorphic forms that contribute to inter-individual difference in responses to drugs metabolized by P450 2D6. The objectives of this work are to identify the type of adduct formed between P450 2D6 and the drug Schering 66712 - the first known mechanism based-inhibitor of 2D6 and a piperazine- containing compound structurally representative of numerous drugs. Multiple experimental approaches including gel electrophoresis with 14C-labeled compound, HPLC, molecular modeling, and mass spectrometry, will be used to understand the nature of the interaction between Schering 66712 and P450 2D6. Finally, we will identify metabolites of Schering 66712 that may be important for its activation. We believe that the knowledge gained from these experiments will contribute to the understanding of how piperazine-containing compounds interact with P450 2D6 and aid in future drug design that seeks to avoid this type of drug induced inhibition that can lead to unfavorable drug-drug interactions. Importantly, the project proposed here will contribute to the understanding of mechanism-based inhibition of P450 2D6 - a highly polymorphic, important enzyme in drug metabolism for which little is known of its mechanism-based inhibition. PUBLIC HEALTH RELEVANCE: Adverse drug-drug interactions are common among individuals who take multiple drugs (both over the counter and prescribed), particularly among older persons. A significant cause of drug-drug interactions is inactivation by drugs of the enzymes responsible for metabolism of other co-administered drugs. The research proposed here will benefit human health by adding to our understanding of how certain classes of drugs may interact in individuals and cause drug-drug induced unfavorable medical events.

描述（由申请人提供）：人类细胞色素 P450 酶是一类含血红素的酶，参与类固醇、维生素、类花生酸和异生物质（如药物、复杂植物生物碱、致癌物和其他小分子）的代谢。通过对人类基因组进行测序，已确定了 57 个家族成员。 P450 在几乎所有药物代谢中的作用使得该酶家族在医学和人类健康领域引起了极大的兴趣。虽然只有大约十几个 P450 参与药物代谢，但它们能够代谢数十万种化合物。药物代谢 P450 酶中如此广泛的底物特异性的一个警告是，这些酶也容易受到其自身反应产物的抑制。这种类型的抑制称为基于机制的抑制，并导致酶不可逆的失活。作为基于机制的抑制剂的化合物是理解这些酶的结构/功能的重要工具。由于它们共价连接到其酶靶标，因此基于机制的抑制剂可以帮助识别酶机制中的重要氨基酸侧链。此外，了解基于机制的抑制所涉及的途径和药物功能组可以有助于未来药物的合理设计。本研究的总体目标是了解不同化合物对 P450 不可逆抑制的机制。一种重要的药物代谢酶是 P450 2D6。虽然该酶占肝脏 P450 总量的不到 5%，但负责约 25% 的药物化合物的代谢。该酶还表现出多种多态性，导致个体间对 P450 2D6 代谢的药物的反应存在差异。这项工作的目的是确定 P450 2D6 和药物 Schering 66712 之间形成的加合物的类型 - 第一个已知的基于机制的 2D6 抑制剂和结构上代表多种药物的含哌嗪化合物。多种实验方法，包括 14C 标记化合物凝胶电泳、HPLC、分子建模和质谱分析，将用于了解先灵 66712 和 P450 2D6 之间相互作用的性质。最后，我们将鉴定先灵 66712 的代谢物，这些代谢物可能对其激活很重要。我们相信，从这些实验中获得的知识将有助于理解含哌嗪化合物如何与 P450 2D6 相互作用，并有助于未来的药物设计，以避免这种类型的药物诱导抑制，从而导致不利的药物相互作用。重要的是，这里提出的项目将有助于理解 P450 2D6 的基于机制的抑制，P450 2D6 是药物代谢中高度多态性的重要酶，对其基于机制的抑制知之甚少。公共卫生相关性：药物间不良相互作用在服用多种药物（非处方药和处方药）的个人中很常见，尤其是老年人。药物间相互作用的一个重要原因是药物使负责其他共同给药药物代谢的酶失活。这里提出的研究将增进我们对某些类别的药物如何在个体中相互作用并导致药物引起的不利医疗事件的理解，从而有益于人类健康。