Structural Studies of Ribonucleotide Reductase Complexes

核糖核苷酸还原酶复合物的结构研究

• 批准号: 8013604
• 负责人: Nozomi Ando
• 金额: $ 5.13万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8013604
• 关键词: Active Sites; Affinity; Antineoplastic Agents; Binding; Biological Models; Chemistry; Complex; Crystallization; DNA Repair; DNA biosynthesis; Data; Deoxyribonucleotides; Diphosphates; Docking; Drug Delivery Systems; Drug Design; Enzymes; Equilibrium; Escherichia coli; Future; Gases; Health; Human; Individual; Lasers; Methods; Modeling; Molecular; Molecular Sieve Chromatography; Molecular Weight; Organism; Oxidoreductase; Pharmaceutical Preparations; Phase; Proteins; Radial; Resolution; Ribonucleotide Reductase; Ribonucleotides; Roentgen Rays; Shapes; Site; Solutions; Structure; Time; X-Ray Crystallography; anticancer research; base; cancer therapy; design; dimer; gemcitabine; inhibitor/antagonist; insight; light scattering; monomer; protein structure; public health relevance; response

DESCRIPTION (provided by applicant): Ribonucleotide reductases (RNRs) are multi-subunit enzymes that are important targets for anti-cancer therapy and thus, directly relevant to human health. Intact complexes of class la RNRs, which include human and E. coli RNRs, have never been visualized by structural methods. Additionally, the oligomerization states of the inhibited class Ia RNR complexes are not well established, and it has been suggested that the inhibited RNRs may exist as higher order oligomers than the active complex. Incubation with the mechanism-based inhibitor and chemotherapeutic drug, gemcitabine (2',2'-difluoro-2'-deoxycytidine) diphosphate, has been shown to yield stable inhibited complexes of human and E. coli RNRs. Here, we propose a structural study of E. coli and human RNRs using X-ray crystallography and small-angle X-ray scattering (SAXS). Aim 1: To determine the quaternary structures of human and E. coli RNRs in solution using SAXS. The SAXS structures can be used to validate the docking model and future crystal structures of RNR complexes. The proposed solution SAXS studies will provide insight into how E. coli and human RNRs may form different oligomeric species in response to inhibitors and more significantly, how quaternary structure may regulate the overall activity of class la RNRs. Aim 2: To determine the crystal structure of human RNR inhibited by gemcitabine. Crystal structures of the gemcitabine-bound human RNR complex will allow us to identify how this drug may modify the active site and disrupt the catalytically essential radical transfer This structure will also allow us to observe the binding interactions between the subunits for the first time as well as provide insight into the future design of chemotherapeutic drugs that target this enzyme. PUBLIC HEALTH RELEVANCE: Ribonucleotide reductase is a protein found in all organisms that is an important target for cancer drugs such as gemcitabine. Unlike many other proteins that are drug targets, however, the complete structure of this protein has never been solved. By studying the structure of this protein, we will understand more about cancer drugs that are currently in use and aid future drug design efforts.

描述（由申请人提供）：核糖核苷酸还原酶（RNR）是多生育酶，是抗癌治疗的重要靶标，因此与人类健康直接相关。包括人和大肠杆菌RNR的类La RNR的完整复合物从未通过结构方法可视化。此外，抑制类Ia RNR复合物的寡聚状态尚未确定，并且已经提出，抑制的RNR可能是高阶低聚物而言，而不是活跃的复合物。与基于机理的抑制剂和化学治疗药物吉西他滨（2'，2'-二氟-2'-脱氧胞苷）二磷酸的孵育，已显示出可产生人和大肠杆菌RNR的稳定抑制络合物。在这里，我们建议使用X射线晶体学和小角X射线散射（SAXS）对大肠杆菌和人RNR进行结构研究。目标1：确定使用SAXS中人类和大肠杆菌RNR的第四纪结构。 SAXS结构可用于验证RNR复合物的对接模型和未来的晶体结构。拟议的解决方案SAXS研究将提供有关大肠杆菌和人类RNR如何形成不同的寡聚物种，以响应抑制剂，更重要的是，季季结构如何调节LA RNR类的整体活性。目标2：确定吉西他滨抑制的人RNR的晶体结构。吉西他滨结合的人RNR复合物的晶体结构将使我们能够确定该药物如何修饰活性位点并破坏催化催化的基本自由基转移该结构，该结构还将使我们能够第一次观察亚基之间的结合相互作用，并洞悉靶向该enzyme的化学治疗药物的未来设计。 公共卫生相关性：核糖核苷酸还原酶是在所有生物体中发现的一种蛋白质，是吉西他滨等癌症药物的重要靶标。但是，与许多其他是药物靶标的蛋白不同，该蛋白质的完整结构从未得到解决。通过研究该蛋白质的结构，我们将更多地了解目前正在使用的癌症药物，并帮助未来的药物设计工作。