IMP Dehydrogenase and the Hydra of Cancer Chemotherapy

IMP脱氢酶和癌症化疗的水螅

基本信息

批准号：
7391775
负责人：
GEORGE Douglas MARKHAM
金额：
$ 26.28万
依托单位：
RESEARCH INST OF FOX CHASE CAN CTR
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2010-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7391775
关键词：
6-Mercaptopurine Active Sites Affect Affinity Animal Model Anions Antineoplastic Agents Binding Binding Sites Biological Preservation Catalysis Chemotherapy-Oncologic Procedure Chromosomes, Human, 16-18 Clinical Code Cysteine DNA Dependence Dissociation Docking Electron Spin Resonance Spectroscopy Environment Enzymes Escherichia coli GTP-Binding Proteins Genes Genetic Guanine Nucleotides Human Hydra Polyps Hydrolysis IMP Dehydrogenase Immunosuppressive Agents In Vitro Inosine 5&apos -Phosphate Dehydrogenase Inhibitor Isoenzymes Isotopes Kinetics Libraries Ligands Light Malignant Neoplasms Mediating Metabolic Metabolic Activation Metabolism Methods Monovalent Cations Mycophenolic Acid NADH Nicotinamide adenine dinucleotide Nucleotide Biosynthesis Oxidoreductase Oxygen Isotopes Pharmaceutical Preparations Physiological Pliability Positioning Attribute Property Protein Dynamics Protein Region Proteins Purines RNA chemical synthesis Rate Reaction Research Design Retinitis Pigmentosa Role Signal Transduction Site Solutions Spectrum Analysis Spin Labels Structure Sulfur Surgical Flaps Testing Therapeutic Agents Thioinosine Time Treatment Protocols Variant Viral Viscosity Water Work adduct analog antimicrobial chemotherapeutic agent chemotherapy clinical efficacy in vivo inhibitor/antagonist insight ionization novel oxidation purine reaction rate research study tiazofurin adenine dinucleotide xanthosine monophosphate

项目摘要

DESCRIPTION (provided by applicant): lnosine-5'-monophosphate dehydrogenase (IMPDH, IMP:NAD oxidoreductase, E.G. 1.2.1.14) catalyzes the rate-limiting step in guanine nucleotide biosynthesis, the oxidation of IMP to xanthosine monophosphate (XMP). IMPDH has a central role in DNA and RNA syntheses, in G-protein mediated signal transduction, and in intermediary metabolism. IMPDH is a target for anticancer, anti-viral, immunosuppressive and anti-microbial chemotherapeutic inhibitors, but is an activator of other drugs. An integrated combination of kinetic, spectroscopic and genetic methods will be used to understand the catalytic mechanism, including the contribution of protein flexibility, and the metabolic role of the evolutionary conserved subdomain of unknown function. The catalytic mechanism of human IMPDH will be characterized by kinetic and UV spectroscopic methods. The reaction of the anticancer agent 6-mercaptopurine ribotide (6MPRT), for which IMPDH catalyzes an essential metabolic activation, will be emphasized. How 6MPRT affects inhibition by clinically used inhibitors that bind at the NAD site will be determined. The reverse of the IMPDH reaction will be investigated to provide insight into the interconversion of XMP and the covalent enzyme-XMP* intermediate. Whether the monovalent cation activator K+, and NAD binding site inhibitors, activate oxygen isotope exchange between XMP and water or restrict water accessibility will enhance the understanding of this reaction. The contribution of protein dynamics to the catalytic efficiency of this flexible enzyme will be determined from the viscosity dependence of the reaction rates. How ligands modulate the flexibility of the protein will be assessed by site-directed spin labeling and EPR spectroscopy. The metabolic role of the subdomain will be determined from the in vivo consequences of deletion of the subdomain within the chromosome of the E. coli model organism. A complementary study will employ a computational docking screen between the crystal structure of the domain and metabolite structures. Interactions with potential ligands will be tested by NMR and for modulation of IMPDH activity. These results will reveal the inner working of an essential enzyme and whether there is promise for enhancing clinical efficacy through combinations of known drugs or the discovery of novel subdomain ligands.

描述（由申请人提供）：LNOSINE-5'-单磷酸脱氢酶（IMPDH，IMP：NAD氧化还原酶，例如1.2.1.14）催化了鸟嘌呤核苷酸生物合成的速率限制步骤，IMP对Xanththosinthosynthososinthosonthosophosinthosophosinthosophosinsonophossonphosophosynophosphosathosypophossonphosphosathosyphospophate（XMP）催化。 IMPDH在DNA和RNA合成，G蛋白介导的信号转导和中间代谢中具有中心作用。 IMPDH是抗癌，抗病毒，免疫抑制和抗菌化学治疗抑制剂的靶标，但是其他药物的激活剂。动力学，光谱和遗传方法的综合组合将用于了解催化机制，包括蛋白质柔韧性的贡献以及未知功能的进化保守亚域的代谢作用。人IMPDH的催化机制将以动力学和紫外线光谱法的特征。将强调抗癌剂6-羟核苷核苷酸（6MPRT）的反应，为此，IMPDH催化了必不可少的代谢激活。将如何确定6年度的临床使用抑制剂在NAD部位结合的抑制作用。将研究IMPDH反应的相反，以洞悉XMP和共价酶-XMP*中间体的相互转换。无论是单价阳离子激活剂K+和NAD结合位点抑制剂，都可以激活XMP与水之间的氧同位素交换，还是限制了水的可及性，都会增强对该反应的理解。蛋白质动力学对该柔性酶的催化效率的贡献将取决于反应速率的粘度依赖性。配体如何通过定点的自旋标记和EPR光谱来评估蛋白质的柔韧性。亚域的代谢作用将取决于大肠杆菌模型生物体染色体中亚域缺失的后果。互补的研究将采用域结构和代谢物结构的晶体结构之间的计算对接屏幕。与潜在配体的相互作用将通过NMR和IMPDH活性调节测试。这些结果将揭示基本酶的内部工作，以及是否有希望通过已知药物的组合或发现新型亚域配体来增强临床疗效。