Small Molecule Inhibitors of Malate Synthase against M. Tuberculosis

描述(由申请人提供)：这份R21探索性建议使用了一种综合的、以目标为导向的方法来合理开发药物，这些药物可能有效地缩短结核病的治疗时间和/或改善耐多药结核病的治疗。结核病研究界已经达成了广泛的共识，即缩短药物治疗持续时间而不增加复发率的关键在于对结核分枝杆菌非复制性持久性(NRP)所必需的蛋白质进行特定靶向。一个这样的靶点是苹果酸合成酶(MS)。已有研究表明，MS对小鼠的持续生长至关重要，并且在NRP的体外模型中过度表达。最近在MS蛋白的结构阐明和MS的功能分析方面的成功打开了一条途径，将计算机辅助药物设计方法与药物化学努力相结合，以发现新的治疗NRP TB的药物。我们假设，使用计算机辅助药物设计和药物化学的组合来识别和设计多发性硬化的抑制剂是可能的。将在全细胞水平上筛选那些在低微摩尔范围内表现出抗MS活性的化合物，以在基于Wayne低氧模型的微板法中杀灭复制和NRP结核分枝杆菌的能力，并就哺乳动物细胞毒性进行选择性。这一迭代过程有望产生几种低微摩尔、铅或类药物的MS抑制剂，这些线索将是进一步开发的候选药物，包括更广泛的药物化学努力和后续项目中对NRP的动物模型评估。为了实现这一目标，我们的具体目标如下：(1)通过寻找与MS的天然底物接近的类似物，并利用从头/理性药物设计，在虚拟聚焦组合文库和商业可用化合物数据库的电子筛选中，鉴定MS的铅或药物样低分子量抑制剂；(2)检测抑制MS功能活性的候选药物。(3)鉴定对活跃生长和/或非复制型、持久性(NRP)结核分枝杆菌具有显著选择性活性的化合物。根据活性、细胞毒性和由此产生的选择性指数确定优先顺序。公共卫生相关性：这项提案旨在寻找新的苹果酸合成酶抑制剂，这是非复制性持久性结核病的潜在新靶点。该项目首次将与NRP相关的靶标苹果酸合成酶、具有优化发现有用先导化合物机会的特性的化合物库、计算机辅助药物设计方法和药物化学结合在一起。

DESCRIPTION (provided by applicant): This R21 exploratory proposal uses an integrated target-oriented approach in the rational development of drugs that may effectively shorten the duration of therapy in tuberculosis and/or improve the treatment of multi-drug resistant TB. There exists a broad consensus in the TB research community that the key to shortening the duration of drug therapy without an increase in relapse rates lies in the specific targeting of proteins that are essential to the non-replicating persistence (NRP) of Mycobacterium tuberculosis. One such target is malate synthase (MS). It has been shown that MS is crucial for persistent growth in mice and is over-expressed in vitro models of NRP. Recent success in the structure elucidation of the MS protein and the availability of functional assays for MS opens a way to apply computer-aided drug design methods in concert with medicinal chemistry efforts to discover new therapeutic agents for NRP TB. We hypothesize that it would be possible to identify and design inhibitors for MS using a combination of computer-aided drug design and medicinal chemistry. Those compounds demonstrating activity at low micromolar range against MS will be screened at the whole cell level for the ability to kill replicating and NRP M. tuberculosis in a microplate assay based on the Wayne low oxygen model and for selectivity with respect to mammalian cell toxicity. This iterative process is expected to yield several low micromolar, lead- or drug-like inhibitors of MS. Such leads would be candidates for further development including more extensive medicinal chemistry efforts and the evaluation in animal models of NRP in subsequent projects. To achieve this goal, our specific aims are as follow: (1) Identify lead- or drug-like low molecular weight inhibitors of MS using a search for close analogs of the natural substrates of MS and identification of new inhibitors using de novo/rational drug design, in silico screening of virtual focused combinatorial libraries and the databases of commercially available chemical compounds; to synthesize the best candidates; (2) Assay candidate drugs for their inhibition of MS functional activity. (3) Identify compounds demonstrating significant selective activity against actively growing and/or non-replicating, persistent (NRP) Mycobacterium tuberculosis. Prioritize on the basis of activity, cytotoxicity and resultant selectivity indices. PUBLIC HEALTH RELEVANCE: This proposal is intended to find new malate synthase inhibitors, a potential new target for non- replicating persistent tuberculosis. This project brings together for the first time an NRP-associated target, malate synthase, libraries of compounds with properties that optimize the chances of finding useful lead compounds, computer-aided drug design approach, and medicinal chemistry.