Novel Inhibitors to DHPS to Probe Catalytic Mechanism & Therapeutic Potential - r

新型 DHPS 抑制剂探索催化机制

基本信息

批准号：
8510547
负责人：
Richard E. Lee
金额：
$ 36.4万
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 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8510547
关键词：
4-Aminobenzoic Acid 6-hydroxymethyl-7,8-dihydropterin Active Sites Amino Acids Animals Anions Anti-Bacterial Agents Anti-Infective Agents Bacillus anthracis Bacteria Binding Binding Sites Biochemistry Biological Assay Biology Calorimetry Catalysis Chemicals Clinical Communicable Diseases Communities Complex Computational Biology Crystallography Data Development Diet Dihydropteroate Synthase Diphosphates Disease Drug Design Drug effect disorder Drug resistance Ensure Enzymatic Biochemistry Enzymes Folate Folate Biosynthesis Pathway Francisella tularensis Funding Future Goals Immune Individual Infection Joints Kinetics Lead Mammals Measures Microbiology Molecular Mutation Organism Pathway interactions Patients Pattern Pharmaceutical Chemistry Pharmaceutical Preparations Pneumocystis Principal Investigator Pterins Publishing Reaction Resistance Resistance development Role Series Site Site-Directed Mutagenesis Staphylococcus aureus Structure Sulfonamides Techniques Testing Therapeutic Therapeutic Agents Thermodynamics Time X-Ray Crystallography Yersinia pestis analog antimicrobial antimicrobial drug base chemical synthesis clinically significant design dihydropteroate drug discovery enzyme mechanism feeding flexibility fungus in vivo inhibitor/antagonist insight methicillin resistant Staphylococcus aureus microbial mutant novel novel therapeutics pathogen resistance mutation scaffold screening structural biology success sulfa drug unpublished works

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 a target of antibacterial agents for over 70 years. Sulfa drugs inhibit the enzyme dihydropteroate synthase (DHPS) in the pathway by acting as non-productive substrate analogs of p-aminobenzoic acid (pABA). However, the flexible pABA binding site is structurally susceptible to resistance mutations, and the sulfa drugs 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 can potentially be 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 proposal. Another goal will be to understand the molecular and functional basis of sulfa drug resistance to avoid this problem in our future drug designs. This comprehensive approach will require the joint expertise of the two principal investigators in structural biology, medicinal chemistry, biochemistry, computational biology and microbiology. The project will also incorporate the relatively new technique of fragment based drug discovery to identify novel small inhibitory chemical scaffolds that can readily be elaborated by chemical synthesis. Exciting new data described in the application provide strong support that the project can realize its ultimate goal which is to rapidly develop new antimicrobials that minimize the emergence of drug resistance. Although we aim to develop broad-spectrum anti-infective agents, our microbiological screening will focus on S. aureus and P. jirovecii that have emerged as particularly problematical infectious disease agents in the U.S. in recent years.

描述（由申请人提供）：叶酸生物合成是一种必不可少的细菌途径，在上等动物中不存在，它一直是抗菌剂的靶标，已有70多年的历史了。 Sulfa药物通过充当P-氨基苯甲酸（PABA）的非生产性底物类似物，抑制途径中二氢蛋白酶合酶（DHP）。然而，柔性PABA结合位点在结构上易受抗性突变，而Sulfa药物在治疗上迅速变得无效。相比之下，第二DHPS底物（ptherin-磷酸盐）的结合位点被埋在保守的口袋中，该袋耐受突变的可能性较小。我们建议生成新的有效DHP抑制剂，这些抑制剂专门接合该口袋。这些抑制剂可能有可能发展为仍靶向叶酸合成但避免抗性问题的新型治疗剂。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。 DHP基本上缺乏此信息，并且了解DHP在分子水平上的催化作用将是该提案的核心目标。另一个目标是了解Sulfa耐药性的分子和功能基础，以避免我们将来的药物设计中的这一问题。这种全面的方法将需要两个主要研究者在结构生物学，药物化学，生物化学，计算生物学和微生物学方面的共同专业知识。该项目还将结合相对较新的基于碎片的药物发现技术，以识别可通过化学合成很容易阐述的新型小型抑制性化学支架。应用程序中描述的令人兴奋的新数据提供了强有力的支持，该项目可以实现其最终目标，即迅速开发新的抗菌剂，以最大程度地减少耐药性的出现。尽管我们旨在开发广谱抗感染剂，但我们的微生物筛查将集中在近年来美国特别有问题的传染病药物中。