Inhibitors of sulfate assimilation as new therapy for TB

硫酸盐同化抑制剂作为结核病的新疗法

• 批准号: 6641361
• 负责人: STEFAN HEMMERICH
• 金额: $ 10万
• 依托单位: THIOS PHARMACEUTICALS, INC.
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2003-11-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6641361
• 关键词: antitubercular agents; chemical registry /resource; combinatorial chemistry; drug discovery /isolation; enzyme inhibitors; gene complementation; gene deletion mutation; microorganism metabolism; miscellaneous oxidoreductase; recombinant proteins; sulfur compounds; tuberculosis

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis (M. tuberculosis) is a major pathogen of global importance. Despite the availability of chemotherapy and the Bacille Calmette-Guerin vaccine, M. tuberculosis continues to claim more lives than any other single infectious agent. Recent years have seen increased incidence of tuberculosis in both developing and industrialized countries, the widespread emergence of drug-resistant strains and a deadly synergy with the human immunodeficiency virus. The limitation of current therapy originates from the widespread occurrence of antibiotic resistant strains and also the requirement for prolonged and uninterrupted administration of antibiotics. Thus, new classes of antibiotics are desperately needed. Sulfur-containing metabolites, including the essential amino acids cysteine and methionine, and the virulence factors mycothiol and sulfolipid-1, are crucial for the infectivity of M. tuberculosis. Their biosynthesis involves the sulfate assimilation pathway, which has no counterpart in humans. Since the enzymes in this pathway comprise a central hub of metabolism and are unique to bacteria, we propose that these enzymes are prime targets for anti-mycobacterial therapy. This proposal focuses on 5'-adenosinephosphosulfate (APS) reductase (CysH) as a target for small molecule drug development. In preliminary work, we have 1) confirmed the APS reductase activity of M. tuberculosis CysH using genetic complementation in E. coli, and 2) demonstrated that genetic deletion of CysH from a pathogenic strain of M. tuberculosis renders the mutant unable to establish infection in a mouse model of tuberculosis. In specific aim 1 of this proposal we shall screen a compound library for inhibitors of M. tuberculosis sulfate assimilation using an E. coli complementation assay. In specific aim 2 we shall set up cell-free homogenous assays for recombinant M. tuberculosis CysH, examine our leads from the primary screen for their ability to directly inhibit this enzyme, and optimize these leads through medicinal chemistry. In specific aim 3 the best compounds will be examined using in vitro susceptibility studies of clinical isolates of M. tuberculosis. In phase II of this study, the inhibitor leads from our feasibility study will be examined for bacteriostatic and bacteriocidic efficacy in mouse models of tuberculosis. The long-term objective of this study is to develop novel antibiotics for more effective treatment of human tuberculosis and other mycobacterial diseases.

描述（由申请人提供）：结核分枝杆菌（M.结核病）是全球重要的主要病原体。尽管有化疗和卡介苗的可用性，M。肺结核继续比任何其他单一传染病夺去更多的生命。近年来，结核病在发展中国家和工业化国家的发病率都有所增加，抗药菌株广泛出现，并与人体免疫缺陷病毒产生致命的协同作用。目前治疗的局限性源于抗生素耐药菌株的广泛发生，以及需要长期和不间断地施用抗生素。因此，迫切需要新型抗生素。 含硫代谢产物，包括必需氨基酸半胱氨酸和蛋氨酸，以及毒力因子真菌硫醇和硫脂-1，对M.结核它们的生物合成涉及硫酸盐同化途径，这在人类中没有对应的途径。由于该途径中的酶包括代谢的中心枢纽，并且是细菌所特有的，因此我们建议这些酶是抗分枝杆菌治疗的主要靶点。该提案关注5 '-腺苷磷酸硫酸（APS）还原酶（CysH）作为小分子药物开发的靶点。在前期工作中，我们证实了M.结核病CysH基因互补技术在E. coli中的CysH基因缺失;结核病使突变体不能在结核病小鼠模型中建立感染。在本提案的具体目标1中，我们将筛选用于M.结核硫酸盐同化使用E. coli互补试验。在具体目标2中，我们将建立重组M的无细胞均相测定。结核病CysH，检查我们的线索，从他们的能力，直接抑制这种酶的初步筛选，并通过药物化学优化这些线索。在具体目标3中，将使用M临床分离株的体外敏感性研究来检查最佳化合物。结核在本研究的第II阶段，将在结核病小鼠模型中检查我们可行性研究中的抑制剂先导化合物的抑菌和杀菌功效。本研究的长期目标是开发新的抗生素，以更有效地治疗人类结核病和其他分枝杆菌疾病。