Structural and Biochemical Studies of LpxC Inhibition

LpxC 抑制的结构和生化研究

基本信息

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
项目类别：
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

项目摘要

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.

项目概要/摘要脂质 A（内毒素）是一种基于葡萄糖胺的糖脂，构成外膜的外单层。革兰氏阴性菌的膜；它也是导致生命的脂多糖的活性成分威胁革兰氏阴性败血性休克。脂质 A 生物合成是几乎所有生物体中都保守的重要途径革兰氏阴性生物。脂质A生物合成的关键步骤由UDP-3-O-(酰基)-N-催化乙酰氨基葡萄糖脱乙酰酶（LpxC）。因为 LpxC 是脂质 A 生物合成中必需的酶，并且与任何已知的哺乳动物蛋白质不具有序列或结构同源性，它是新型抗生素的设计。事实上，已经发现了几种有效的 LpxC 抑制剂，它们表现出各种不同的作用。抗生素活性程度。一些最近发现的化合物也表现出时间依赖性 LpxC 抑制，这是抗生素非常需要的一种特性，因为酶/抑制剂的半衰期很长复杂的。不同的 LpxC 直向同源物之间可能存在显着程度的局部结构变异。许多大肠杆菌 LpxC 的有效抑制剂对不同的 LpxC 酶相对无活性，尤其是来自铜绿假单胞菌，这是囊性纤维化患者死亡的主要原因。 CHIR-090，最迄今为止发现的有效 LpxC 抑制剂对多重耐药革兰氏阴性病原体无效例如乙酸钙不动杆菌和洋葱伯克霍尔德杆菌。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一起严重阻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 很大程度上未知的分子特征潜在的抑制剂特异性和时间依赖性抑制，以及（2）利用这些信息来改善两者下一代 LpxC 靶向抗生素的效力和抑制谱。这个目标将是通过对不同的 LpxC 直系同源物的详细结构和生化研究来实现代表性的LpxC抑制剂，并通过基于此的新型化合物的设计、合成和评价结构见解。项目叙述（公共卫生相关性声明）缺乏对多重耐药革兰氏阴性病原体（包括菌株）的有效治疗对所有临床可用抗生素具有抗药性的假单胞菌或不动杆菌强调了紧迫性需要具有新颖作用机制的抗生素。我们提出的 LpxC 的结构和生化研究，LpxC 是脂质 A 生物合成中必需的酶，革兰氏阴性菌的新型抗生素靶标，将揭示抑制剂的分子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针对广谱革兰氏阴性病原体的有效 LpxC 靶向抗生素。