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）：人类中的细胞色素P450酶是涉及类固醇，维生素，eiconsanoids和异种生物的代谢的含血红素酶的家族，例如药物，复杂的植物生物碱，癌细胞，癌细胞和其他小分子。随着人类基因组的测序，已经确定了五十七个家庭成员。 P450在几乎所有药物的代谢中的作用使这个对医学和人类健康兴趣的酶家族。虽然只有大约十二个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酶中这种广泛的底物特异性的一个警告是，酶也容易受到其自身反应的抑制作用。这种抑制作用称为基于机制的抑制作用，导致酶不可逆地失活。充当基于机理的抑制剂的化合物是理解这些酶的结构/功能的重要工具。由于它们与酶靶标共价附着，因此基于机制的抑制剂可以帮助鉴定酶机制中重要的氨基酸侧链。同样，了解基于机制的抑制涉及的途径和药物官能团可以有助于对未来药物的合理设计。这项研究的总体目标是了解不同化合物的P450不可逆抑制的机制。一种重要的药物代谢酶是P450 2D6。虽然占总肝脏P450的5％，但该酶的代谢占药品化合物的约25％。该酶还显示出多种多态性形式，这些形式在对P450 2d6代谢的对药物的反应中有助于个体间差异。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 - 基于2d6的首个已知机制抑制剂，以及含有花叶素的化合物在结构上代表了许多药物。多种实验方法，包括具有14C标记化合物，HPLC，分子建模和质谱法的凝胶电泳，将用于了解Schering 66712和P450 2D6之间相互作用的性质。最后，我们将确定Schering 66712的代谢物，这对于其激活可能很重要。我们认为，从这些实验中获得的知识将有助于理解含哌嗪的化合物如何与P450 2D6相互作用，并帮助未来的药物设计，该设计旨在避免这种类型的药物诱导的抑制作用，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基于机制的P450 2d6的抑制作用 - 一种高度多态性，重要的药物代谢酶，对其基于机制的抑制作用几乎不知所措。公共卫生相关性：在服用多种药物（无论是在柜台和处方）中，尤其是在老年人中服用多种药物的个体中，不良药物的相互作用很常见。药物相互作用的一个重要原因是导致其他共同药物代谢的酶的药物失活。此处提出的研究将通过增加我们对某些类别的药物可能在个体中相互作用并引起药物引起的不利医疗事件的理解来使人类健康受益。