Targets in Mycobacterium Tuberculosis: Stress Resistance & Repair

结核分枝杆菌的目标：抗应激性

基本信息

批准号：
7574500
负责人：
CARL Francis NATHAN
金额：
$ 88.32万
依托单位：
WEILL MEDICAL COLL OF CORNELL UNIV
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：
2005-06-01 至 2010-12-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7574500
关键词：
3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)4-ethoxymethylene-2-phenyl-2-oxazoline-5-one AIDS/HIV problem Abbreviations Acetyl Coenzyme A Alcohols Alleles Amino Acids Anabolism Antibiotics Antioxidants Attenuated Back Bacterial Infections Biological Assay Bioterrorism Carboxy-Lyases Catabolism Cause of Death Cell Culture Techniques Cell Wall Cells Chemicals Citric Acid Citric Acid Cycle Coenzyme A Complement Complex DNA DNA Damage DNA Repair DNA Repair Enzymes Disease Drug Kinetics Drug Resistant Tuberculosis Drug resistance Economics Electrons Enzymes Equilibrium Fatty Acids Figs - dietary Folate Fright Gene Expression Microarray Analysis Gene Targeting Generations Genes Grant Growth HIV Infections Harvest Health Heme Homologous Gene Human Human Genome Hydrogen Peroxide Immune Immune response Immunity In Vitro Incidence Infection Inhibitory Concentration 50 Interferons Intermediate resistance Keto Acids Kinetics Libraries Limb structure Lipids Mediating Metabolic Metabolism Methodology Multi-Drug Resistance Multidrug-Resistant Tuberculosis Mus Mutagenesis Mutation Mycobacterium tuberculosis NADH NOS2A gene New Agents Nitrites Nitrogen Nucleic Acids Nucleotide Excision Repair Operative Surgical Procedures Operon Oxidases Oxidoreductase Pathway interactions Peroxidases Peroxides Peroxonitrite Phagocytes Phagosomes Pharmaceutical Preparations Phenotype Physiological Production Proteins Reporting Research Personnel Resistance Reverse Transcriptase Polymerase Chain Reaction Safety Solutions Specificity Staging Stress Structure Structure-Activity Relationship Succinate-semialdehyde dehydrogenase Succinates System Testing Thiamine Pyrophosphate Time Tuberculosis Ultraviolet Rays Water Work X-Ray Crystallography acetoacetyl CoA alkyl hydroperoxide reductase bactericide base chemical genetics chemotherapy combinatorial dihydrolipoamide acyltransferase dihydrolipoamide dehydrogenase dihydrolipoamide succinyltransferase drug development high throughput screening homologous recombination human NOS2A protein inhibitor/antagonist isoniazid ketoglutarate dehydrogenase killings lipoamide macrophage man mutant nitrosative stress novel pathogen peroxynitrite reductase propionyl-coenzyme A pyruvate dehydrogenase reactive oxygen intermediate repaired small molecule libraries succinic semialdehyde thioredoxin reductase ultraviolet

项目摘要

DESCRIPTION (provided by applicant): M. tuberculosis (Mtb), a global health crisis and bioterrorism threat, is increasingly drug-resistant, but little new chemotherapy has emerged in decades. A fresh approach to chemotherapy is to target pathways essential for the pathogen to survive in its metabolic niche in host macrophages. This application is based on the hypothesis that Mtb requires 3 enzymes to survive under energy-poor, oxidative and nitrosative conditions in the phagosome: (1) Lipoamide dehydrogenase (Lpd) serves in pyruvate dehydrogenase and probably in branched chain ketoacid dehydrogenase as well as in peroxynitrite reductase /peroxidase and thus is key for net synthesis of acyl CoA's, the precursors of fatty acids, and for resistance to reactive nitrogen intermediates (RNI). (2) a-ketoglutarate (KG) decarboxylase (KDC) converts KG to succinic semialdehyde (SSA), replacing KG dehydrogenase, which Mtb lacks. SSA dehydrogenase converts SSA to succinate and may thereby connect the oxidative and reductive limbs of Mtb's citric acid cycle (CAC). KDC may therefore be important for Mtb's generation of energy, reducing equivalents, amino acids and heme. (3) Ultraviolet repair (Uvr) B, part of the nucleotide excision repair pathway, was found by saturation transposon mutagenesis to be essential for Mtb to survive RNI and to kill mice. KDC and UvrB lack human homologs, and Lpd's crystal structure shows key differences from the human enzyme. We will use allelic replacement to disrupt the 3 genes encoding these enzymes, or establish their essentiality; use conventional and novel combinatorial libraries to identify chemical inhibitors of each enzyme; analyze the crystal structures of Lpd and KDC with and without inhibitors; and assess these enzymes as potential targets for new chemotherapeutics. Antibiotics to date only target enzymes that synthesize protein, nucleic acids, cell walls and folate. The fundamental novelty of this work is to broaden the range of targets to include enzymes of intermediary metabolism and DNA repair.

描述（由申请人提供）：结核分枝杆菌（Mtb）是一种全球健康危机和生物恐怖主义威胁，其耐药性日益增强，但几十年来几乎没有出现新的化疗药物。化疗的一种新方法是针对病原体在宿主巨噬细胞的代谢生态位中生存所必需的途径。该应用基于这样的假设：Mtb 需要 3 种酶才能在吞噬体中的能量贫乏、氧化和亚硝化条件下生存：(1) 硫辛酰胺脱氢酶 (Lpd) 在丙酮酸脱氢酶中发挥作用，并可能在支链酮酸脱氢酶中发挥作用，也可在支链酮酸脱氢酶中发挥作用。过氧亚硝酸还原酶/过氧化物酶，因此是酰基辅酶A（脂肪酸前体）的净合成以及抗性的关键活性氮中间体（RNI）。 (2)α-酮戊二酸(KG)脱羧酶(KDC)将KG转化为琥珀半醛(SSA)，取代Mtb缺乏的KG脱氢酶。 SSA 脱氢酶将 SSA 转化为琥珀酸，从而连接 Mtb 柠檬酸循环 (CAC) 的氧化和还原分支。因此，KDC 对于 Mtb 产生能量、还原当量、氨基酸和血红素可能很重要。 (3) 紫外线修复 (Uvr) B 是核苷酸切除修复途径的一部分，通过饱和转座子诱变发现，它对于 Mtb 在 RNI 中存活并杀死小鼠至关重要。 KDC 和 UvrB 缺乏人类同源物，并且 Lpd 的晶体结构显示出与人类酶的关键差异。我们将使用等位基因替换来破坏编码这些酶的 3 个基因，或确定它们的重要性；使用传统和新颖的组合文库来识别每种酶的化学抑制剂；分析有和没有抑制剂的 Lpd 和 KDC 的晶体结构；并评估这些酶作为新化疗药物的潜在靶点。迄今为止，抗生素仅针对合成蛋白质、核酸、细胞壁和叶酸的酶。这项工作的根本新颖之处在于扩大了靶标范围，将中间代谢和 DNA 修复的酶包括在内。