Discovery of Phospopantetheinyl Transferse Inhibitors Against Mycobacterium tuberculosis

抗结核分枝杆菌磷酸泛酰基转移酶抑制剂的发现

• 批准号: 10298705
• 负责人: Jeffrey Aube
• 金额: $ 80.77万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-13 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10298705
• 关键词: Age; Anabolism; Antimycobacterial Agents; Antitubercular Agents; Back; Biochemical; Biological Assay; Cardiotoxicity; Carrier Proteins; Chemicals; Client; Clinic; Clinical; Collaborations; Complement; Critiques; Crystallization; Disease; Drug Kinetics; Drug resistance; Fatty Acids; Foundations; Goals; Growth; Health Personnel; In Vitro; Knock-out; Laboratories; Lead; Length; Mammalian Cell; Measurement; Mediating; Medical; Medicine; Metabolic; Microsomes; Modeling; Mus; Mycobacterium tuberculosis; Organism; Orthologous Gene; Pharmaceutical Preparations; Property; Protocols documentation; Reporting; Resistance; Resolution; Rifampin; Safety; Science; Series; Sodium Channel; Structure; Structure-Activity Relationship; Therapeutic; Therapeutic Agents; Treatment Protocols; Tuberculosis; Variant; Virulence Factors; Work; X-Ray Crystallography; analog; design; drug candidate; drug-sensitive; extensive drug resistance; high throughput screening; in silico; in vivo; inhibitor/antagonist; knock-down; macrophage; metabolomics; mycobacterial; novel; novel therapeutics; phosphopantetheinyl transferase; physical property; pre-clinical; preclinical development; programs; response; scaffold; synergism; tuberculosis drugs; tuberculosis treatment

Abstract Tuberculosis (TB) presents an ongoing global challenge to medical science that will only be met by multiple approaches. Due to the length of even “routine” TB therapy and the age of existing drugs – which contributes to the emergence of devastating resistant forms of the disease – the discovery of new drugs, especially those that function by new mechanisms of action, has become critical. In early 2019, a team including the present laboratory reported AU 8918 as the first high-quality inhibitor of 4'-phosphopantetheinyl transferase (PptT). PptT, which catalyzes the placement of a 4'-phosphopantetheinyl moiety onto a client carrier protein, is essential for the biosynthesis of mycobacterial fatty acids and virulence factors. PptT represents a valuable anti-TB target because (1) it is essential for mycobacterial tuberculosis (Mtb) survival in vitro and in mice, (2) it is divergent from the closest host ortholog, and (3) it is distinct from all targets of established TB drugs. In addition, its inhibition has been shown (4) to effectively kill Mtb including multi- and extensively-drug-resistant variants and (5) to block Mtb growth in mice, while (6) sparing other bacterial or mammalian cells. The primary hit compound, AU 8918, has an IC50 of 2.3 M in biochemical assays of PptT inhibition, a MIC90 of 3.1 M against Mtb in vitro, and has some physical properties features consistent with advancement as a drug candidate, but suffers from off-target cardiotoxicity likely associated with sodium channel blockade. The present proposal seeks to support an ongoing collaboration between three laboratories that share the common goal to design, synthesize, and characterize PptT inhibitors suitable for pre-clinical development. The availability of five high resolution co-crystal structures of AU 8918 and analogs bound to Mtb PptT has been leveraged to establish a robust in silico modeling protocol for the preliminary assessment of analogs. Several avenues to create novel PptT inhibitors are proposed, including (1) SAR exploration of AU 8918, (2) discovery and exploration of new scaffolds arising from bioisosteric replacements of the amidinourea subunit of AU 8918, and (3) new hits arising from an ongoing screen against PptT. We will characterize inhibitors by (1) biochemical PptT inhibition, (2) X-ray crystallography of inhibitor•PptT co-crystals, and (3) advanced biochemical characterization (including intracellular macrophage activity measurements, verification of on-target activity by knockdown/knockout studies, safety profiling against off-target liabilities, pharmacokinetic and metabolic characterization, metabolomics, and synergy studies). The final goal of the project is to identify 1–2 advanced compounds for advancement to in vivo studies in Mtb infected mice, having the following properties: (<0.1 M potency against PptT, <1 M MIC90 against Mtb, retention of positive physical properties, and lacking cardiotoxicity or activity (>30 M inhibition) at relevant Ca and Na channels.

摘要 结核病（TB）对医学科学提出了一个持续的全球挑战，只有通过多种方法才能应对。 接近。由于即使是“常规”结核病治疗的时间长度和现有药物的年龄-这有助于 这种疾病的毁灭性耐药形式的出现-新药的发现，特别是那些 通过新的作用机制发挥作用，已变得至关重要。2019年初，包括目前实验室在内的团队 报道了Au 8918作为第一个高质量的4 ′-磷酸泛酰巯基乙胺基转移酶（PptT）抑制剂。PptT， 催化4 '-磷酸泛酰巯基乙胺基部分放置在客户载体蛋白上，对于 分枝杆菌脂肪酸和毒力因子的生物合成。PptT是一个有价值的抗结核靶点 因为（1）它对结核分枝杆菌（Mtb）在体外和小鼠中的存活至关重要，（2）它是不同的 与最接近的宿主直系同源物，和（3）它与已建立的TB药物的所有靶标不同。另外它的 抑制作用已显示（4）有效地杀死Mtb，包括多重和广泛耐药变体， (5)以阻断小鼠中的Mtb生长，同时（6）保留其它细菌或哺乳动物细胞。主要目标化合物 Au 8918在PptT抑制的生化测定中的IC 50为2.3 μ M，体外抗Mtb的MIC 90为3.1 μ M， 并且具有与作为候选药物的进展相一致的一些物理性质特征，但患有 脱靶心脏毒性可能与钠通道阻滞相关。 本提案旨在支持三个实验室之间正在进行的合作， 共同目标是设计、合成和表征适合于临床前开发的PptT抑制剂。的 五个高分辨率共晶体结构的Au 8918和类似物结合到Mtb PptT的可用性已经被 用于建立用于类似物初步评估的稳健的计算机模拟方案。几 提出了制备新型PptT抑制剂的途径，包括：（1）Au 8918的SAR探测;（2）发现PptT抑制剂 以及探索由Au 8918的脒基亚基的生物电子等排置换产生的新支架， 以及（3）从针对PptT的正在进行的筛选中产生的新命中。我们将通过（1）生物化学 PptT抑制，（2）抑制剂·PptT共晶体的X射线晶体学，和（3）高级生物化学 表征（包括细胞内巨噬细胞活性测量，通过细胞内巨噬细胞的活性来验证靶向活性） 敲除/敲除研究、针对脱靶倾向的安全性分析、药代动力学和代谢 表征、代谢组学和协同作用研究）。该项目的最终目标是确定1-2个先进的 用于在Mtb感染的小鼠中进行体内研究的化合物，其具有以下性质：（<0.1 μ M 对PptT的效力，对Mtb的MIC 90 <1 μ M，保留阳性物理性质， 相关Ca和Na通道的心脏毒性或活性（>30 μ M抑制）。