Novel fluoroquinolones for killing dormant Mycobacterium tuberculosis

用于杀死休眠结核分枝杆菌的新型氟喹诺酮类药物

基本信息

批准号：
8885631
负责人：
KARL A DRLICA
金额：
$ 38.52万
依托单位：
RBHS-NEW JERSEY MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-05-15 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8885631
关键词：
3-Dimensional Achievement Aerosols Alleles Antibiotics Antimicrobial Resistance Attention Bacillus (bacterium)Bacteria Bacterial Infections Binding Biochemical Biochemistry Biological Assay Biology Calorimetry Cause of Death Cell Death Cells Chromosomes Cleaved cell Clinical Complex Computing Methodologies Cultured Cells DNA DNA Gyrase DNA Topoisomerases Disease Dose Drug resistance Edetic Acid Enzymes Escherichia coli Fluoroquinolones Fostering Goals Growth Infection Knowledge Lead Magnesium Measures Mediating Modeling Molecular Molecular Models Moxifloxacin Mus Mycobacterium tuberculosis Nitric Oxide Organism Outcome Output Oxygen Pathway interactions Pharmaceutical Chemistry Pharmaceutical Preparations Pharmacologic Substance Process Property Protein Biosynthesis Proteins Quantitative Structure-Activity Relationship Quinolones Reactive Oxygen Species Records Resistance Roentgen Rays Role Rotation Structure System Testing Time Titrations Topoisomerase Tuberculosis Variant Work antimicrobial cell killing chelation compliance behavior crosslink defined contribution design drug structure experience in vivo inhibitor/antagonist killings magnesium ion molecular modeling mutant mycobacterial novel programs protein structure function quinolone resistance research study stoichiometry tuberculosis treatment

项目摘要

DESCRIPTION (provided by applicant): Tuberculosis is a serious airborne disease for which drug resistance has become a major issue. The long treatment time (6-24 months) is particularly problematic because it creates difficulties in maintaining patient adherence to therapy. Sporadic treatment then fosters the emergence of antimicrobial-resistant Mycobacterium tuberculosis, the causative agent of tuberculosis. Long treatment times are needed, presumably because even active infections contain some non-growing (dormant) bacilli that are not readily killed by most antimicrobials. Our goal is to obtain new fluoroquinolones that rapidly kill non-growing M. tuberculosis and would thereby reduce treatment time radically. As part of their mechanism of action, quinolones trap DNA gyrase as drug-enzyme-DNA complexes in which the DNA is broken but held together by protein. Formation of these complexes, which are thought to block bacterial growth, is reversed by chelation of magnesium ion. Recent work leads us to propose that at lethal quinolone concentrations, which are higher than required to block growth, additional drug binding generates a new complex that is not reversed by chelation of magnesium. We propose that the new complex leads to chromosome fragmentation, which in growing cells is followed by a lethal cascade of reactive oxygen species. Only a quinolone subset kills non-growing cells. These quinolones are proposed to stimulate chromosome fragmentation that causes death directly, without requiring a cascade of reactive oxygen species. The above scenario will be tested by designing, synthesizing, and characterizing new quinolones and quinolone- derived structures for interactions with gyrase and for killing non-growing cells. In aim 1, tests with cultured cells will examine relationships between experimental compounds and gyrase structure, using gyrase mutants, in-vivo crosslinking, drug structure variation, and molecular modeling. The primary readout will be cell death when protein synthesis is inhibited to eliminate the lethal pathway operating with growing cells. In aim 2, experiments will focus on biochemical properties of the newly discovered quinolone-gyrase-DNA complex formed at the elevated drug concentrations required to kill bacteria. Attention will focus on drug structures that facilitate release of DNA breaks from gyrase-mediated constraint. In aim 3, drug structure- lethal activity relationships will be determined with computational analyses (eg. 3-dimensional quantitative structure-activity relationship models) that do not rely on knowledge of drug-gyrase interactions. Superior compounds from work on each of the three aims will be examined for lethality with three mycobacterial growth-arrest systems. The expected outcomes are lead compounds and novel rules for developing new quinolone-type inhibitors that rapidly kill non-growing, persister cells.

描述（由申请人提供）：结核病是一种严重的空中疾病，耐药性已成为主要问题。长期治疗时间（6-24个月）特别有问题，因为它在维持患者遵守治疗方面遇到困难。然后，零星的治疗促进了结核病的抗菌结核分枝杆菌的出现，这是结核病的病因。需要长时间的治疗时间，大概是因为即使是主动感染也含有一些非生长（休眠）杆菌，这些杆菌不容易被大多数抗菌剂杀死。我们的目标是获取新的氟喹诺酮类药物，这些氟喹诺酮迅速杀死非生长的结核分枝杆菌，从而从根本上减少治疗时间。作为其作用机理的一部分，喹诺酮类诱捕DNA回旋酶是药物 - 酶-DNA复合物，其中DNA被损坏但被蛋白质固定在一起。这些复合物的形成被认为可以阻止细菌生长，这是通过镁离子的螯合而逆转的。最近的工作使我们提出，在致命的奎诺酮浓度下，喹诺酮浓度高于阻断生长所需的含量，额外的药物结合会产生一种新的复合物，这种新复合物不会被镁的螯合所逆转。我们建议新的复合物会导致染色体碎片化，在生长的细胞中，这是活性氧的致命级联。只有一个喹诺酮子集可杀死非生长的细胞。提出了这些喹诺酮来刺激直接导致死亡的染色体碎片化，而无需级联反应性氧。上述情况将通过设计，合成和表征新的奎诺酮和奎诺酮衍生结构来测试，以与回旋酶相互作用并杀死非生长的细胞。在AIM 1中，使用回旋酶突变体，体内交联，药物结构变异和分子建模，使用培养细胞的测试将检查实验化合物与回旋酶结构之间的关系。当蛋白质合成被抑制以消除与生长细胞生长的致命途径时，主要的读数将是细胞死亡。在AIM 2中，实验将集中在新发现的喹诺酮gyrase-DNA复合物的生化特性上，该特性是在杀死细菌所需的升高药物浓度下形成的。注意将集中于促进Gyrase介导的约束中DNA断裂的药物结构。在AIM 3中，药物结构 - 致命活性关系将通过计算分析（例如3维定量结构 - 活性关系模型）确定，这些关系不依赖于药物gyrase相互作用的知识。通过三个分枝杆菌生长骚扰系统，将检查三个目标中每个目标的工作中的出色化合物。预期的结果是铅化合物和新规则，用于开发新的喹诺酮型抑制剂，这些喹啉型抑制剂迅速杀死了非生长的持久细胞。