REDUCTASE/P450 INTERACTION AFFECTS CARCINOGEN ACTIVATION

还原酶/P450 相互作用影响致癌物激活

• 批准号: 3197995
• 负责人: HENRY W STROBEL
• 金额: $ 23.34万
• 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/3197995
• 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.

致癌物激活的调节受到相互作用的影响 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 的影响，从而影响致癌物质的激活。 这 因素包括 P450 和还原酶的结构域，即 膜结合域、底物结合域和结合 通过互补电荷配对相互作用的域。 我们将 通过一系列化学修饰来定义这些域 蛋白质和一系列定点诱变研究。 在每个 方面，该研究的目的是明确a中哪些氨基酸残基 特定的结构域控制该结构域与底物的相互作用， 膜或配对蛋白以及这些残基/结构域如何协同作用 调节致癌物质的激活。 为了实现这些目标，我们将定义氨基酸 负责与关键羧基电荷配对的 P450 残基 还原酶的基团。 我们将定义涉及的氨基酸残基 使用光亲和底物类似物与 P450 进行底物结合，并且 定点诱变。 我们将定义 NADPH 结合区域并 P450 还原酶的黄素结合区域。 这些参数将是 评估它们在底物代谢总体控制中的作用。 为了 例如，我们将确定与 P450 结合的底物如何影响 P450 与还原酶的相互作用。