Novel Inhibitors to DHPS to Probe Catalytic Mechanism & Therapeutic Potential

新型 DHPS 抑制剂探索催化机制

基本信息

批准号：
7617662
负责人：
STEPHEN W WHITE
金额：
$ 61.41万
依托单位：
ST. JUDE CHILDREN'S RESEARCH HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-06-01 至 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7617662
关键词：
4-Aminobenzoic Acid Acids Active Sites Affinity Amino Acids Animals Anti-Bacterial Agents Anti-Infective Agents Antibiotics Arts Bacillus anthracis Binding Binding Sites Biochemistry Biological Warfare Candida albicans Catalysis Categories Collaborations Computational Biology Computer software Data Development Dihydropteroate Synthase Diphosphates Disease Drug Design Drug resistance Enzymes Escherichia coli Evaluation Folate Folate Biosynthesis Pathway Folic Acid Antagonists Francisella tularensis Funding Genes Genomics Goals Immunocompromised Host Individual Infection Institution Laboratories Libraries Ligands Locales Methods Microbiology Modeling Molecular Molecular Conformation Mutation Mycobacterium tuberculosis Organism Orthologous Gene Pathway interactions Pharmaceutical Chemistry Pharmaceutical Preparations Proteins Protozoa Protozoan Infections Pseudomonas aeruginosa Pterins Quantitative Structure-Activity Relationship Research Research Personnel Resistance Role Salmonella Screening procedure Serum Site Site-Directed Mutagenesis Solid Specificity Staphylococcus aureus Streptococcus pneumoniae Structure Sulfonamides Techniques Testing Therapeutic Therapeutic Agents X-Ray Crystallography Yersinia pestis analog antimicrobial bacterial resistance base biodefense chemical synthesis cytotoxicity design dihydropteroate drug discovery enzyme mechanism flexibility fungus high throughput screening in vivo inhibitor/antagonist insight interest methicillin resistant Staphylococcus aureus microorganism molecular dynamics novel novel therapeutics programs resistance mutation resistant strain scaffold small molecule structural biology text searching virtual

项目摘要

DESCRIPTION (provided by applicant): Folate biosynthesis is an essential bacterial pathway that is absent in higher animals, and it has been an effective target of antibacterial agents for over 70 years. The sulfonamide drugs inhibit a key enzyme in the pathway, dihydropteroate synthase (DHPS), by acting as non-productive substrate analogs of paminobenzoic acid (pABA). However, the flexible pABA binding site is structurally susceptible to resistance mutations, and the sulfonamides are rapidly becoming therapeutically ineffective. In contrast, the binding site of the second DHPS substrate, pterin-pyrophosphate, is buried in a conserved pocket that is less likely to tolerate mutations. We propose to generate new classes of potent DHPS inhibitors that specifically engage this pocket. These inhibitors have the potential of being developed into novel therapeutic agents that still target folate synthesis but which avoid the problems of resistance. To generate effective inhibitors of any enzyme, it is crucial to understand the structure and mechanism of its active site. This information is largely absent for DHPS, and understanding how DHPS performs catalysis at the molecular level will be a central goal of the application. This comprehensive project will encompass biochemistry, structural biology, medicinal chemistry, computational biology, and microbiology, and will be performed in two laboratories at neighboring institutions in Memphis. The central focus of the project is the design and synthesis of novel small molecules that can be used to probe the DHPS mechanism and also be evaluated as DHPS inhibitors. Promising inhibitor scaffolds will then be tested for their potential as anti-microbials by direct screening of select organisms. The more potent inhibitors will be used to create derivative libraries for further screening and evaluation. The use of state-of-the-art drug discovery software, library synthesis, high-throughput screening and X-ray crystallography are central features of the research. Our goal is to provide a solid platform for the development of new, desperately-needed, broad-spectrum anti-infectives agents. However, we are also focused on developing specific therapies for the category A biowarfare agents B. anthracis, Y. pestis and F. tularensis, as well as for pathogenic protozoa and fungi.

描述（由申请人提供）：叶酸生物合成是高等动物中不存在的重要细菌途径，并且 70 多年来一直是抗菌剂的有效靶点。磺酰胺类药物通过充当帕氨基苯甲酸 (pABA) 的非生产性底物类似物来抑制该途径中的关键酶二氢叶酸合酶 (DHPS)。然而，灵活的 pABA 结合位点在结构上容易受到耐药性突变的影响，磺胺类药物很快就会变得无效。相比之下，第二种 DHPS 底物蝶呤焦磷酸的结合位点被埋在一个保守的口袋中，该口袋不太可能容忍突变。我们建议开发新一类有效的 DHPS 抑制剂，专门针对这个口袋。这些抑制剂有可能被开发成新型治疗剂，其仍然以叶酸合成为目标，但避免了耐药性问题。为了产生任何酶的有效抑制剂，了解其活性位点的结构和机制至关重要。 DHPS 基本上缺乏这些信息，了解 DHPS 如何在分子水平上发挥催化作用将是该应用的中心目标。这个综合项目将涵盖生物化学、结构生物学、药物化学、计算生物学和微生物学，并将在孟菲斯邻近机构的两个实验室进行。该项目的核心重点是设计和合成新型小分子，这些小分子可用于探测 DHPS 机制，也可作为 DHPS 抑制剂进行评估。然后将通过直接筛选选定的生物体来测试有前途的抑制剂支架的抗微生物潜力。更有效的抑制剂将用于创建衍生文库以供进一步筛选和评估。使用最先进的药物发现软件、文库合成、高通量筛选和 X 射线晶体学是该研究的核心特征。我们的目标是为开发急需的新型广谱抗感染药物提供坚实的平台。然而，我们还专注于开发针对 A 类生物战剂炭疽芽孢杆菌、鼠疫耶尔森菌和土拉热杆菌，以及致病性原生动物和真菌的特定疗法。