REDUCTASE/P450 INTERACTION AFFECTS CARCINOGEN ACTIVATION

还原酶/P450 相互作用影响致癌物激活

• 批准号: 3197994
• 负责人: HENRY W STROBEL
• 金额: $ 22.26万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3197994
• 关键词: NADPH cytochrome c2 reductase; active sites; affinity labeling; carcinogens; cytochrome P450; enzyme complex; enzyme induction /repression; enzyme mechanism; enzyme structure; enzyme substrate analog; enzyme substrate complex; flavins; laboratory rat; site directed mutagenesis

Regulation of carcinogen activation is affected by interaction of cytochrome P450 and cytochrome P450 reductase, as well as by other factors. We propose to define the factors which govern the interaction of reductase and P450 and thereby influence carcinogen activation. The factors include the structural domains of P450 and reductase, i.e. membrane binding domains, substrate binding domains, and the binding domains which interact through complementary charge pairing. We will define these domains through a series of chemical modifications of the proteins and a series of site directed mutagenesis studies. In each aspect, the aim of the study is to specify which amino acid residues in a particular domain govern the interaction of that domain with substrate, membrane, or pair protein and how these residues/domains act in concert to regulate carcinogen activation. In pursuit of these goals, we will define the amino acid residues of P450s responsible for charge pairing with critical carboxyl groups of the reductase. We will define the amino acid residues involved in substrate binding to P450 using a photoaffinity substrate analogue and site directed mutagenesis. We will define the NADPH binding region and the flavin binding regions of P450 reductase. These parameters will be evaluated for their role in overall control of substrate metabolism. For example, we will determine how substrate binding to P450 affects the interaction of P450 with reductase.

致癌物活化的调节受相互作用的影响 细胞色素P450和细胞色素P450还原酶，以及其他 因素 我们建议定义控制相互作用的因素 还原酶和P450，从而影响致癌物质的活化。 的 因子包括P450和还原酶的结构域，即 膜结合结构域、底物结合结构域和结合结构域 通过互补电荷配对相互作用的结构域。 我们将 通过一系列的化学修饰来定义这些结构域， 蛋白质和一系列定点突变研究。 在每个 一方面，该研究的目的是指定在一个特定的氨基酸残基中， 特定的结构域控制该结构域与基底的相互作用， 膜或配对蛋白以及这些残基/结构域如何协同作用 来调节致癌物的激活。 为了实现这些目标，我们将定义氨基酸 负责与关键羧基进行电荷配对的P450残基 还原酶的基团。 我们将定义所涉及的氨基酸残基 在底物中使用光亲和底物类似物与P450结合， 定点诱变 我们将定义NADPH结合区， P450还原酶的黄素结合区。 这些参数将 评价它们在底物代谢的总体控制中的作用。 为 例如，我们将确定底物与P450的结合如何影响蛋白质的表达。 P450与还原酶相互作用。