Structure and Function of Cytochrome P450 17A1

细胞色素 P450 17A1 的结构和功能

基本信息

批准号：
8499381
负责人：
Jeffrey Aube
金额：
$ 26.78万
依托单位：
UNIVERSITY OF KANSAS LAWRENCE
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8499381
关键词：
Active Sites Amino Acids Androgens Basic Science Binding Catalysis Chemistry Crystallography Cytochrome P450 Defect Development Disease Enzyme Interaction Enzymes Estrogens Evaluation Generations Goals Gonadal Steroid Hormones Health Heme Homology Modeling Hormone Responsive Human Hydrogen Bonding Hydroxylation Investigation Iron Knowledge Libraries Ligand Binding Ligands Lyase Malignant Neoplasms Malignant neoplasm of ovary Malignant neoplasm of prostate Membrane Membrane Proteins Metabolism Metastatic Prostate Cancer Mixed Function Oxygenases Molecular Mutagenesis Mutation Outcome Pathway interactions Pharmaceutical Preparations Pharmacologic Substance Play Polycystic Ovary Syndrome Positioning Attribute Production Proteins Protons Reaction Reproductive Biology Research Roentgen Rays Role Side Steroid biosynthesis Steroids Structure Structure-Activity Relationship Substrate Interaction Testing Time United States National Institutes of Health base biological systems chemotherapy design disorder control enzyme activity enzyme structure experience hormone biosynthesis improved information model inhibitor/antagonist knowledge base malignant breast neoplasm meetings novel programs protein structure function scaffold small molecule tool

项目摘要

DESCRIPTION (provided by applicant): Cytochrome P450 17A1 (CYP17A1) is a dual-function monooxygenase with a key role in human steroidogenesis. Since CYP17A1 is essential for androgen and estrogen production, understanding how this enzyme functions has practical value in reproductive biology, hormone-responsive chemotherapy, and the understanding of diseases resulting from CYP17A1 defects. To date, investigations of CYP17A1 have been limited by the absence of experimental structural information of this membrane protein. The first structures now show that inhibitors bind very differently from proposed and provide a new opportunity to evaluate CYP17A1 binding, catalysis, and inhibition at a substantially more detailed level. The objective of this proposal is to understand the mechanisms controlling the multifunctional reactions of CYP17A1 through convergent structural, synthetic, and functional approaches. Our central hypothesis is that steroidal substrates bind in an overall orientation similar to that observed for inhibitors in the new structures, but with tight spatial control of liand position and proton delivery directing substrates toward either hydroxylation or lyase reactions. Specifically we will test this hypothesis by 1) generation of X-ray structures that determine substrate binding orientations and interactions with CYP17A1, 2) functional evaluation of key amino acids in substrate binding and catalysis and of proposed mechanisms for hydroxylase vs. lyase reactions, and 3) testing our understanding of CYP17A1 function via the design, synthesis, and evaluation of novel probe substrates and inhibitors. The expected outcome is a detailed understanding of the structural features that control binding and catalysis of native CYP17A1 substrates for both catalytic reactions. The proposed research generates a substantial knowledgebase to guide the design, development, and improvement of more effective pharmaceutical inhibitors with improved selectivity for CYP17A1 and its lyase activity. These outcomes meet NIH goals by probing an important enzyme in hormone biosynthesis that can potentially be manipulated for the treatment of androgen-sensitive and estrogen-responsive cancers, as well as other steroid-related diseases.

描述（由申请人提供）：细胞色素P450 17A1（CYP17A1）是一种双功能单加氧酶，在人类类固醇生成中具有关键作用。由于CYP17A1对于雄激素和雌激素的产生至关重要，因此了解该酶功能如何在生殖生物学，激素反应性化疗以及对CYP17A1缺陷引起的疾病的理解中具有实际价值。迄今为止，由于缺乏该膜蛋白的实验结构信息，对CYP17A1的研究受到限制。现在的第一个结构表明，抑制剂的结合与提议的结合非常不同，并提供了一个新的机会，可以在基本上更详细的水平上评估CYP17A1结合，催化和抑制。该建议的目的是了解通过收敛结构，合成和功能方法来控制CYP17A1多功能反应的机制。我们的中心假设是，类固醇底物的结合在与新结构中抑制剂相似的总体方向上结合，但是对LIAND位置的空间控制和质子递送的严格控制，将底物引导朝向羟基化或裂解酶反应。具体而言，我们将通过1）生成X射线结构来检验这一假设，这些结构确定了底物结合方向以及与CYP17A1的相互作用，2）底物结合和催化中关键氨基酸的功能评估以及针对羟化酶VS.溶酶体反应的提议机制以及提议的机制。 3）通过新型探针底物和抑制剂的设计，合成和评估来测试我们对CYP17A1功能的理解。预期的结果是对控制两种催化反应的天然CYP17A1底物的结合和催化的结构特征的详细理解。拟议的研究产生了一个实质性的知识基础，以指导更有效的药物抑制剂的设计，开发和改进，对CYP17A1及其裂解酶活性的选择性提高了。这些结果通过探测激素生物合成中重要的酶来符合NIH目标，该酶有可能被操纵以治疗对雄激素敏感和雌激素反应性癌症以及其他与类固醇相关的疾病。