Inhibitors of CoA biosynthesis as novel antitubercular and antistaphylococcal agents

项目摘要/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 最致命的传染病是由几个因素造成的，包括a)长期坚持较差 多种药物治疗，b)潜伏(或持续)感染，c)与艾滋病毒和d)耐药结核分枝杆菌混合感染 不受当前结核病治疗影响的人。同样，金黄色葡萄球菌最近也被世界卫生组织列入名单 作为一种新抗生素开发的“高度优先”病原体，因为它作为一种 医院和社区中的主要感染源，毒力增加和耐药性上升 对抗目前的抗葡萄球菌药物。辅酶A(CoA)的生物合成 与几个代谢过程相关，包含一组新出现的抗菌药物设计靶点。 这一途径的小分子抑制剂在以细胞为基础的潜伏结核病模型中显示出活性，增加了 对这一组潜在靶子的兴趣意味着攻击潜在的病原体。同样，辅酶A的生物合成在 金黄色葡萄球菌最近被认为与在厌氧条件下维持生物体有关，一个模型 持续性感染。该项目广泛而长期的目标是开发辅酶A生物合成的抑制剂， 它们作用于结核分枝杆菌和金黄色葡萄球菌的PPCS酶活性，在一定范围内显示整个细胞的活性 作为临床有用药物联合使用的条件和进一步开发的潜力 治疗。这一目标在体外遗传学研究的结果中有坚实的基础，该研究表明 靶标的脆弱性，体内实验表明，PPCS活性的耗尽具有杀菌和 防止小鼠感染结核分枝杆菌。在金黄色葡萄球菌中，一种针对PPCS活性的天然产物显示出高度的 选择性的全细胞活动。这些结果表明，PPCS活性是一个非常有希望的目标，即 易被小分子抑制的。为了开发新的全细胞活性化合物，我们提议 基于已成功用于制备缓蚀剂的成熟策略的缓蚀剂结构 机械上相似的酶，产生的化合物也表现出优异的全细胞活性 对抗结核分枝杆菌和金黄色葡萄球菌。此外，我们建议补充新陈代谢激活和前药 解决制备能够穿过结核分枝杆菌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实现这一目标：1)设计和合成泛化学发光二极管 模拟作为PPCS抑制剂；2)AIM 1代谢激活和PPCS抑制的生化评价 化合物；3)在活跃生长和持续生长的Mtb和S.模型中评价PPCS抑制剂。 金星。制定这些目标是为了系统地优化抑制剂的结构并遵循它们的 通过酶分析和全细胞分析的靶向活性和选择性，后者包括对 野生型Mtb和金黄色葡萄球菌和突变Mtb菌株(显示靶标特异性)，潜伏期/持久性模型 结核分枝杆菌和金黄色葡萄球菌的生长，以及体外巨噬细胞模型(在结核杆菌的情况下)。

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).