Inhibitors of CoA biosynthesis as novel antitubercular and antistaphylococcal agents

项目总结/摘要 由结核分枝杆菌（Mtb）引起的结核病（TB）仍然是世界上最严重的结核病之一。 最致命的传染病，因为几个因素，包括a）长期坚持不良 多药治疗，B）潜伏性（或持续性）感染，c）与HIV合并感染和d）耐药Mt B菌株 不受当前结核病疗法影响的疾病。同样，金黄色葡萄球菌最近被世界卫生组织列入 作为新抗生素开发方面的“高优先级”病原体，由于其作为一种 医院和社区的主要传染源，以及毒性增加和耐药性增强 对抗目前的抗葡萄球菌药物。辅酶A（CoA）的生物合成，一种必需的辅因子 与几种代谢过程相关，包含一组新兴的抗菌药物设计靶点。 该途径的小分子抑制剂在基于细胞的潜伏性TB模型中显示出活性， 对这一组靶标的兴趣作为攻击潜伏病原体的潜在手段。类似地， S.金黄色葡萄球菌最近与在厌氧条件下维持生物体有关， 持续感染。该项目的广泛的长期目标是开发CoA生物合成的抑制剂， 其作用于Mtb和S的PPCS酶活性。金黄色葡萄球菌，其在一定范围内显示出全细胞活性。 条件和进一步发展为临床上有用的药物的潜力， 治疗。这一目标在体外遗传研究的结果中有着坚实的基础，这些研究表明， 目标的脆弱性，以及体内实验表明PPCS活性的消耗是杀菌的， 防止小鼠中的Mtb强感染。In S.金黄色葡萄球菌，一种靶向PPCS活性的天然产物， 选择性的全细胞活性。这些结果表明，PPCS活性是一个非常有前途的靶点， 易于被小分子抑制。为了开发新的全细胞活性化合物，我们建议 基于已成功用于制备抑制剂的成熟策略的抑制剂结构 的机制相似的酶，产生的化合物，也显示出良好的全细胞活性 对结核分枝杆菌和S.金黄色。此外，我们还提出了补充代谢活化和前药 解决制备能够穿过Mtb细胞的化合物的已知挑战的方法 信封.我们将通过三个具体目标来实现这一目标：1）Pan-CMP的设计和合成 作为PPCS抑制剂的模拟物; 2）Aim 1的代谢活化和PPCS抑制的生化评价 化合物;和3）在活跃生长和持久性Mtb和S. 金黄色。制定这些目标是为了系统地优化抑制剂的结构，并遵循其 通过酶法和全细胞试验确定靶向活性和选择性，后者包括针对 野生型Mtb和S.金黄色葡萄球菌和突变型Mtb菌株（以显示靶标特异性），潜伏/持续性 Mtb和S.金黄色葡萄球菌和离体巨噬细胞模型（在Mtb的情况下）。

PROJECT SUMMARY/ABSTRACT Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), continues to be one of the world’s deadliest infectious diseases because of several factors, including a) poor adherence to the long-term multidrug therapy, b) latent (or persistent) infection, c) co-infection with HIV and d) drug-resistant Mtb strains that are unaffected by current TB therapies. Similarly, Staphylococcus aureus was recently listed by the WHO as a “high priority” pathogen in regards to new antibiotic development, due to its increasing prevalence as a major infectious agent both in hospitals and in the community, and to increased virulence and rising resistance against current antistaphylococcal agents. The biosynthesis of coenzyme A (CoA), an essential cofactor relevant to several metabolic processes, contains an emerging set of targets for antibacterial drug design. Small molecule inhibitors of this pathway have shown activity in a cell-based model of latent TB, increasing interest in this set of targets as a potential means attacking the latent pathogen. Similarly, CoA biosynthesis in S. aureus has recently been associated with maintaining the organism under anaerobic conditions, a model for persistent infections. The broad, long-term objective of this project is to develop inhibitors of CoA biosynthesis, which act on the PPCS enzyme activity of Mtb and S. aureus, that show whole cell activity under a range of conditions and potential for further development as clinically useful agents that could be used in combination treatments. This goal has strong foundations in results from in vitro genetic studies demonstrating the vulnerability of the target, and in vivo experiments showing that depletion of PPCS activity is bactericidal and prevents a robust Mtb infection in mice. In S. aureus, a natural product that targets PPCS activity shows highly selective whole cell activity. These results suggest that the PPCS activity is a highly promising target that is tractable to inhibition by small molecules. To develop new whole cell active compounds, we are proposing inhibitor structures based on a well-established strategy that has successfully been used to prepare inhibitors of mechanistically similar enzymes, giving rise to compounds that also showed excellent whole cell activity against Mtb and S. aureus. In addition, we are proposing complementary metabolic activation and prodrug approaches to address the known challenge of preparing compounds that are able to cross the Mtb cell envelope. We will pursue this objective through three Specific Aims: 1) Design and synthesis of Pan-CMP mimics as PPCS inhibitors; 2) Biochemical evaluation of metabolic activation and PPCS inhibition of Aim 1 compounds; and 3) Evaluation of PPCS inhibitors in models of actively growing and persistent Mtb and S. aureus. These aims are formulated to systematically optimize the structure of the inhibitors and to follow their on-target activity and selectivity through enzymatic and whole cell assays, the latter including tests against wild-type Mtb and S. aureus and mutant Mtb strains (to show target specificity), models of latent/persistent growth for both Mtb and S. aureus, and an ex vivo macrophage model (in the case of Mtb).