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.

抽象的 结核病 (TB) 对医学科学提出了持续的全球挑战，只有通过多种方式才能应对这一挑战 由于“常规”结核病治疗的时间较长以及现有药物的使用年限，这也导致了结核病治疗的持续时间。 疾病的毁灭性耐药形式的出现——新药的发现，尤其是那些 2019 年初，包括当前实验室在内的一个团队建立了新的作用机制。 据报道，AU 8918 是第一个高质量的 4'-磷酸泛酰胆碱转移酶 (PptT) 抑制剂。 催化 4'-磷酸泛酰胆碱基部分放置到客户载体蛋白上，对于 分枝杆菌脂肪酸和毒力因子的生物合成是一个有价值的抗结核靶标。 因为 (1) 它对于结核分枝杆菌 (Mtb) 在体外和小鼠体内的存活至关重要，(2) 它是不同的 与最接近的宿主直向同源物不同，(3)它与已确定的结核病药物的所有靶点不同。 抑制作用已被证明 (4) 可有效杀死 Mtb，包括多重耐药和广泛耐药变种， (5) 阻断小鼠体内 Mtb 的生长，同时 (6) 不影响其他细菌或哺乳动物细胞。 AU 8918，在 PptT 抑制生化测定中的 IC50 为 2.3 µM，体外针对 Mtb 的 MIC90 为 3.1 µM， 并具有一些与候选药物的进步相一致的物理特性，但受到以下问题的困扰 脱靶心脏毒性可能与钠通道阻断有关。 本提案旨在支持共享以下三个实验室之间的持续合作： 设计、合成和表征适合临床前开发的 PptT 抑制剂的共同目标。 AU 8918 和与 Mtb PptT 结合的类似物的五种高分辨率共晶结构的可用性已得到证实 利用它建立了一个强大的计算机建模协议，用于类似物的初步评估。 提出了创建新型 PptT 抑制剂的途径，包括 (1) AU 8918 的 SAR 探索，(2) 发现 并探索由 AU 8918 脒基脲亚基的生物电子等排替换产生的新支架， (3) 正在进行的 PptT 筛选中产生的新化合物 我们将通过 (1) 生化来表征抑制剂。 PptT 抑制，(2) 抑制剂·PptT 共晶的 X 射线晶体学，以及 (3) 高级生物化学 表征（包括细胞内巨噬细胞活性测量，通过验证目标活性 击倒/敲除研究、针对脱靶责任的安全性分析、药代动力学和代谢 该项目的最终目标是确定 1-2 个高级研究。 用于在 Mtb 感染小鼠中进行体内研究的化合物，具有以下特性：（<0.1 µM 对 PptT 的效力，对 Mtb 的 MIC90 <1 µM，保留了积极的物理特性，并且缺乏 相关 Ca 和 Na 通道的心脏毒性或活性（>30 μM 抑制）。