Rational, structure-based inhibitor design, synthesis and evaluation as a first step towards the discovery of new anti-tuberculosis drugs

合理的、基于结构的抑制剂设计、合成和评估是发现新抗结核药物的第一步

• 批准号: 2433898
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2433898
• 关键词: Rational; structure; based; inhibitor; design

Background: Mycobacterium tuberculosis and M. bovis are the main causes of tuberculosis (TB) in humans and animals respectively. The World Health Organisation (WHO) reported that 1.5M people (including 251K with HIV) died from TB and 10M fell ill in 2018, the highest of any infectious disease. Increasing occurrences of drug resistance to the drugs used to treat TB include strains showing extreme drug resistance (XDR-TB) have been observed. DEFRA reported that 2,805 herds of cattle in Great Britain tested positive for bovine TB in the 12 months to Sept 2018, with 305K cattle having to be slaughtered in GB over the last decade at the cost of £500M. Methods of treating or eradicating TB are therefore crucial to both human and animal health. Mycobacteria have an unusual and more complex cell wall structure than other Gram-positive bacteria. The exterior surface of the bacterium is formed from a hydrophobic, waxy coat of mycolic acids (~C60 long chain fatty acids) (Alderwick et al. Cold Spring Harb Perspect Med. 2015, 5, a021113) that acts as a pseudo-outer membrane. This sits on a polysaccharide structure, arabinogalactan that contains several rare sugars (galactofuranose/arabinofuranose/rhamnose) which is then attached to the peptidoglycan layer. This 'stealth' coat masks the bacteria from its host's defences and allows them to colonize mammalian tissues and form biofilms without triggering a host response. We can selectively target several enzymes unique to Mycobacteria with inhibitors/drugs with a reduced chance of off-target toxicity. Research Project: This will involve the design, synthesis and evaluation of new compounds as putative inhibitors of selected target enzymes: InhA (an enoyl reductase) involved in mycolic acidbiosynthesis; UGM and GlfT2 involved in galactan biosynthesis. There are high resolution X-ray structures available for these enzymes allowing new inhibitor designs to be tested in silico using protein-ligand docking programs including GOLD or OEDocking prior to their synthesis. For InhA, the clinically important mutations that cause resistance are known and new compounds can be docked against these mutants to test if their binding will be impacted. The majority of TB cases are in the third world, therefore new drugs need to be easy to produce and be orally active to minimise their cost.The research will focus on one/two of the enzymes mentioned above. The student will express the enzyme(s) from vectors available in the group and synthesize their assay substrates as necessary. Initial test compounds will be designed by docking existing small molecule/fragment libraries (size

背景：结核分枝杆菌和牛分枝杆菌分别是人类和动物结核病（TB）的主要原因。世界卫生组织 (WHO) 报告称，2018 年有 150 万人（其中 25.1 万人感染艾滋病毒）死于结核病，1000 万人患病，这是所有传染病中最高的。对用于治疗结核病的药物产生耐药性的情况越来越多，其中包括已观察到表现出极端耐药性（XDR-TB）的菌株。 DEFRA 报告称，截至 2018 年 9 月的 12 个月内，英国有 2,805 头牛的牛结核病检测结果呈阳性，过去 10 年英国不得不屠宰 30.5 万头牛，成本达 5 亿英镑。因此，治疗或根除结核病的方法对于人类和动物健康至关重要。与其他革兰氏阳性细菌相比，分枝杆菌具有不寻常且更复杂的细胞壁结构。细菌的外表面由分枝菌酸（~C60 长链脂肪酸）的疏水性蜡质外壳形成（Alderwick 等人，Cold Spring Harb Perspect Med. 2015, 5, a021113），充当伪外膜。它位于多糖结构上，阿拉伯半乳聚糖含有几种稀有糖（呋喃半乳糖/阿拉伯呋喃糖/鼠李糖），然后附着在肽聚糖层上。这种“隐形”外壳使细菌免受宿主防御的影响，使它们能够在哺乳动物组织中定殖并形成生物膜，而不会触发宿主反应。我们可以使用抑制剂/药物选择性地靶向分枝杆菌特有的几种酶，从而减少脱靶毒性的可能性。研究项目：这将涉及新化合物的设计、合成和评估，作为选定目标酶的推定抑制剂：参与霉菌酸生物合成的 InhA（一种烯酰还原酶）； UGM 和 GlfT2 参与半乳聚糖生物合成。这些酶有高分辨率的 X 射线结构，允许在合成之前使用蛋白质配体对接程序（包括 GOLD 或 OEDocking）在计算机上测试新的抑制剂设计。对于 InhA，导致耐药性的临床重要突变是已知的，并且可以将新化合物与这些突变体对接以测试它们的结合是否会受到影响。大多数结核病病例发生在第三世界，因此新药需要易于生产且具有口服活性，以最大限度地降低成本。该研究将集中于上述一种/两种酶。学生将从小组中可用的载体中表达酶，并根据需要合成其测定底物。初始测试化合物将通过对接现有的小分子/片段库（大小