Structural and Biochemical Studies of LpxC Inhibition

LpxC 抑制的结构和生化研究

• 批准号: 7846499
• 负责人: Pei Zhou
• 金额: $ 4.81万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-05 至 2011-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7846499
• 关键词: Acinetobacter; Acinetobacter calcoaceticus; Anabolism; Antibiotics; Area; Bacteria; Binding; Biochemical; Biological Assay; Burkholderia cepacia; Catalysis; Cause of Death; Cell Culture Techniques; Chemicals; Commit; Complex; Development; Diffusion; Endotoxins; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Escherichia coli; Evaluation; Genes; Glucosamine; Goals; Gram-Negative Bacteria; Growth; Half-Life; Human; Individual; Infection; Investigation; Lead; Life; Lipid A; Lipopolysaccharides; Membrane; Modeling; Molecular; Molecular Conformation; Morbidity - disease rate; Multi-Drug Resistance; Mus; N-acetylglucosamine deacetylase; Organism; Orthologous Gene; Pathway interactions; Process; Property; Proteins; Pseudomonas; Pseudomonas aeruginosa; Research; Resistance; Salmonella; Septic Shock; Shigella; Specificity; Testing; Thermolysin; Time; Toxic effect; Uridine; Uridine Diphosphate; Variant; Yersinia; Zinc; abstracting; antimicrobial; bactericide; base; cystic fibrosis patients; design; effective therapy; flexibility; improved; inhibitor/antagonist; insight; killings; metalloenzyme; monolayer; mortality; next generation; novel; pathogen; public health relevance; scaffold

Project Summary/Abstract Lipid A (endotoxin) is a glucosamine-based saccharolipid that constitutes the outer monolayer of the outer membrane of Gram-negative bacteria; it is also the active component of lipopolysaccharide that causes life- threatening Gram-negative septic shock. Lipid A biosynthesis is an essential pathway conserved in virtually all Gram-negative organisms. The committed step of lipid A biosynthesis is catalyzed by UDP-3-O-(acyl)-N- acetylglucosamine deacetylase (LpxC). Because LpxC is an essential enzyme in lipid A biosynthesis and does not share sequence or structural homology with any known mammalian protein, it is an excellent target for the design of novel antibiotics. Indeed, several potent LpxC inhibitors have been discovered that display various degrees of antibiotic activity. Some of the recently discovered compounds also show time-dependent LpxC inhibition, a property that is highly desirable for an antibiotic because of the long half-life of the enzyme/inhibitor complex. A significant degree of local structural variation is likely to exist among different LpxC orthologs. Many of the potent inhibitors of Escherichia coli LpxC are relatively inactive against divergent LpxC enzymes, especially that from Pseudomonas aeruginosa, the leading cause of death in cystic fibrosis patients. CHIR-090, the most potent LpxC inhibitor discovered to date, is ineffective against multidrug-resistant Gram-negative pathogens such as Acinetobacter calcoaceticus and Burkholderia cepacia. This unusual inhibitor specificity and the lack of structural information on various LpxC/inhibitor complexes together severely hinder further optimization of existing LpxC inhibitors. The overall goal of this proposal is (1) to understand the largely unknown molecular features of LpxC underlying inhibitor specificity and time-dependent inhibition and (2) to utilize this information to improve both the potency and spectrum of inhibition for the next generation of LpxC-targeting antibiotics. This goal will be achieved by detailed structural and biochemical studies of divergent LpxC orthologs in complex with representative LpxC inhibitors, and by design, synthesis and evaluation of novel compounds based on structural insights. Project Narrative (Public Health Relevance Statement) The lack of effective treatment for multidrug-resistant Gram-negative pathogens, including strains of Pseudomonas or Acinetobacter that are resistant to all clinically available antibiotics, underscores the pressing need for antibiotics with novel mechanisms of action. Our proposed structural and biochemical studies of LpxC, an essential enzyme in lipid A biosynthesis and a novel antibiotic target of Gram-negative bacteria, will reveal the molecular basis underlying inhibitor specificity and time-dependent inhibition. Our studies have already benefited and will continue to facilitate the development of potent LpxC-targeting antibiotics against a broad spectrum of Gram-negative pathogens.

项目摘要/摘要 脂质A（内毒素）是一种基于葡萄糖的糖粉，构成外部的外部单层 革兰氏阴性细菌的膜；它也是脂多糖的活跃成分，会导致生命 - 威胁革兰氏阴性败血性冲击。脂质生物合成是几乎所有的必不可少的途径 革兰氏阴性生物。脂质的致命步骤A生物合成是由UDP-3-O-（酰基）-n-催化的 乙酰葡萄糖脱乙酰基酶（LPXC）。因为LPXC是脂质A生物合成中必不可少的酶 不与任何已知哺乳动物蛋白共享序列或结构同源性，它是该蛋白的绝佳目标 新型抗生素的设计。实际上，已经发现了几种有效的LPXC抑制剂显示各种 抗生素活性程度。一些最近发现的化合物还显示了时间依赖的LPXC 抑制作用，由于酶/抑制剂的半衰期长，对抗生素非常需要的特性 复杂的。 不同LPXC直系同源物之间可能存在很大程度的局部结构变化。许多 大肠杆菌LPXC的有效抑制剂相对不活跃，针对发散的LPXC酶，尤其是 铜绿假单胞菌是囊性纤维化患者死亡的主要原因。 Chir-090，最多 迄今为止发现的有效LPXC抑制剂对抗多药的革兰氏阴性病原体无效 例如calcoaceticus和burkholderia cepacia。这种不寻常的抑制剂特异性和缺乏 各种LPXC/抑制剂复合物的结构信息共同严重妨碍了进一步的优化 现有的LPXC抑制剂。 该提案的总体目标是（1）了解LPXC的很大未知分子特征 潜在的抑制剂特异性和时间依赖性抑制作用，（2）利用这些信息来改善这两种信息 抑制下一代LPXC靶向抗生素的能力和抑制范围。这个目标将是 通过对发散LPXC直系同源物的详细结构和生化研究实现 代表性LPXC抑制剂，以及基于设计，合成和评估新化合物 结构见解。项目叙述（公共卫生相关声明） 缺乏对多药耐药的革兰氏阴性病原体的有效治疗，包括 对所有临床可用抗生素具有抗药性的假单胞菌或动杆菌，突显了压迫 需要具有新型作用机理的抗生素。 我们提出的对LPXC的结构和生化研究，这是脂质A生物合成和 革兰氏阴性细菌的新型抗生素靶标将揭示分子基础抑制剂的基础 特异性和时间依赖性抑制。我们的研究已经受益，并将继续促进 开发有效的LPXC靶向抗生素针对革兰氏阴性病原体的广泛开发。