Targetting InhA For Anti-TB Drug Discovery

以 InhA 为靶点进行抗结核药物研发

• 批准号: 7007632
• 负责人: PETER J TONGE
• 金额: $ 23.61万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7007632
• 关键词: Mycobacterium tuberculosis; Raman spectrometry; X ray crystallography; acyl coA dehydrogenases; affinity labeling; antitubercular agents; bacterial proteins; combinatorial chemistry; drug design /synthesis /production; drug discovery /isolation; drug screening /evaluation; enzyme inhibitors; ethers; gene expression profiling; isoniazid; microarray technology; peroxidases; phenols; protein protein interaction; site directed mutagenesis; transmission electron microscopy

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis is a major opportunistic pathogen in patients with HIV/AIDS. Current tuberculosis treatment regimes are severely hampered by the occurrence of multidrug resistant strains of M. tuberculosis (MDR-TB) and there is a critical need for the development of novel chemotherapeutics. We will design and synthesize inhibitors of InhA, the enoyl-reductase enzyme from M. tuberculosis (MTB). InhA, which catalyzes the final step in the fatty acid elongation pathway, is a target for the activated form of isoniazid (INH) a front-line anti-TB drug. Importantly, the large majority of INH-resistant isolates result from mutations in KatG, the enzyme that activates INH, rather than from mutations in the ultimate drug target(s). Consequently, it is hypothesized that inhibitors of InhA, which circumvent the need for KatG activation, will form an effective basis for tackling MDR-TB. The lead compound for inhibitor discovery is triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), a compound that inhibits InhA with a Ki value of 0.22 mu/M and which has an MIC99 for MTB of 5 mu/g/mL (17 mu/M). The proposed research includes the following specific aims: (1) We will synthesize a library of triclosan analogs using directed synthesis and parallel synthetic methods. (2) We will determine the inhibitory potency of the analogs and analyze the interaction of promising compounds with InhA using techniques such as kinetics, X-ray crystallography and Raman spectroscopy. (3) We will determine MIC99 values against sensitive and resistant TB strains. To evaluate whether InhA is the target for these compounds we will (i) determine MIC99 values in an MTB strain overexpressing InhA and (ii) use promoter-specific reporter fusions coupled with radiolabeled uptake studies and photoaffinity labeling to investigate the mechanism of compound action in live bacteria. The in vivo activity of promising InhA inhibitors will be further analyzed through the NIAID-funded Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF). Information derived from Aims 2-3 will direct the synthesis of additional compounds which will then be submitted for further rounds of screening and evaluation.

描述（由申请人提供）：结核分枝杆菌是艾滋病毒/艾滋病患者的主要机会病原体。当前的结核病治疗方案受到结核分枝杆菌（MDR-TB）的多药抗性菌株的发生严重阻碍，并且对于开发新型化学治疗剂的发展迫切需要。我们将设计和合成INHA的抑制剂，INHA，结核分枝杆菌（MTB）的烯酰基还原酶。催化脂肪酸伸长途径的最后一步的Inha是激活形式的异尼氏酶（INH）前线抗TB药物的靶标。重要的是，大部分耐INH的分离株是由Katg突变引起的，Katg是激活INH的酶，而不是来自最终药物靶标的突变。因此，假设规避KATG激活的INHA抑制剂将形成解决MDR-TB的有效基础。抑制剂发现的铅化合物是Triclosan（5-氯-2-（2,4-二氯苯氧基）苯酚），该化合物以0.22 mu/m的Ki值抑制INHA，并且MIC99的MIC99对于MTB的MTB为5 mu/g/g/g/ml（17 mu/m）。拟议的研究包括以下具体目的： （1）我们将使用定向合成和平行合成方法合成三氯生类似物库。 （2）我们将使用动力学，X射线晶体学和拉曼光谱学等技术来确定类似物的抑制作用，并分析有希望化合物与INHA的相互作用。 （3）我们将确定针对敏感和抗性结核病菌株的MIC99值。为了评估INHA是否是这些化合物的靶标，我们将（i）确定过表达MTB菌株中的MIC99值，并且（ii）使用特定于启动子特异性的记者融合，以及放射性标记的摄取研究和光附近标记的MIC99值，以研究活细胞中化合物的机制。有望INHA抑制剂的体内活性将通过NIAID资助的结核病抗菌抗菌和协调设施（TAACF）进一步分析。 AIMS 2-3得出的信息将指导其他化合物的综合，然后将其提交以进行进一步的筛选和评估。