Species selective dipeptide inhibitors for Mtb proteasome

Mtb 蛋白酶体的物种选择性二肽抑制剂

• 批准号: 8607117
• 负责人: Gang Lin
• 金额: $ 21.13万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8607117
• 关键词: ATP phosphohydrolase; Abbreviations; Anti-Infective Agents; Antibiotics; Bacteria; Bioavailable; Biochemical; Biological Assay; Biological Availability; Cells; Cessation of life; Chemicals; Client; Collaborations; Complement; Complex; Core Facility; Crystallization; Degradation Pathway; Development; Dipeptides; Drug Kinetics; Enzymes; Genus Mycobacterium; Goals; Growth; Hereditary Disease; Heterogeneity; Human; In Vitro; Inhibitory Concentration 50; Lead; Libraries; Ligase; Mammals; Metabolic; Microsomes; Modeling; Mus; Mycobacterium tuberculosis; Nitric Oxide; Outcome; Oxygen; Peptide Hydrolases; Pharmaceutical Chemistry; Pharmaceutical Preparations; Play; Population; Predisposition; Proteasome Inhibition; Proteins; Research Institute; Resistance; Rifampin; Role; Serum; Starvation; Sterilization; Structure; System; Testing; Therapeutic; Translating; Tuberculosis; Ubiquitin Like Proteins; bactericide; base; design; feeding; in vitro activity; in vivo; inhibitor/antagonist; isoniazid; killings; multicatalytic endopeptidase complex; mycobacterial; nitrosative stress; peptidomimetics; protein degradation; public health relevance; public health research; scale up; screening; stability testing; structural biology; tuberculosis drugs

DESCRIPTION (provided by applicant): In vitro activities do not always translate into in vivo activities, and this is true in Mycobacterium tuberculosis (Mtb) therapeutics. For example, the two first line anti-Mtb drugs isoniazid and rifampicin kill Mtb rapidly in vitro, but their steriliation abilities are slowed and reduced in vivo. Heterogeneity of Mtb populations imparts varied susceptibility to the drugs. In particular, slowly-replicating or non-replicating (collectively "NR) Mtb is non-heritably resistant to most first line anti-TB drugs. Our long-term goal is to develop anti-Mtb drugs that kill NR Mtb populations to complement drugs that kill replicating Mtb populations. During the past eight years, components of a prokaryotic ubiquitin-like protein (Pup)-proteasome system have been discovered. Although the Mtb proteasome is dispensable under standard growth conditions, genetic evidence demonstrates its essentiality for Mtb to survive in mice. We also established the concept that despite the essential role of the proteasome in mammals, small chemical molecules can be discovered with extensive (>1000-fold) species selectivity for inhibiting the Mtb proteasome over the human proteasome, and that such inhibition leads to killing of NR Mtb. In other bacteria, disruption of another regulated protein degradation machine, Clp, has led to killing. Thus, either inhibition or forced activation f chambered proteases may represent a new anti-infective strategy. In our recent screening of 1600 capped dipeptides, we identified a lead compound that potently and species-selectively inhibited the Mtb proteasome over the human proteasome. The inhibitors were bactericidal for non-replicating Mtb in synergy with nitric oxide. Using a competition assay, I confirmed that the dipeptides penetrate the mycobacteria and inhibit the proteasome within them. In this application, we will expand our lead compounds into a small focused compound library whose design and synthesis are guided by substrate-profiling, structural analysis, mycobactericidal activity, and metabolic stability.

描述（由申请方提供）：体外活性并不总是转化为体内活性，在结核分枝杆菌（Mtb）治疗中也是如此。例如，两种一线抗结核药物异烟肼和利福平在体外快速杀死结核分枝杆菌，但它们的灭菌能力在体内减慢和降低。Mtb群体的异质性赋予了对药物的不同敏感性。特别地，缓慢复制或非复制（统称为“NR”）Mtb对大多数一线抗TB药物具有非遗传抗性。我们的长期目标是开发杀死NR Mtb群体的抗Mtb药物，以补充杀死复制Mtb群体的药物。在过去的八年中，原核泛素样蛋白（Pup）-蛋白酶体系统的组成部分已被发现。虽然Mtb蛋白酶体在标准生长条件下是不稳定的，但遗传学证据表明它对Mtb在小鼠中存活的重要性。我们还建立了这样的概念，即尽管蛋白酶体在哺乳动物中起重要作用，但可以发现小化学分子具有广泛的（>1000倍）物种选择性来抑制Mtb蛋白酶体超过人蛋白酶体，并且这种抑制导致NR Mtb的杀伤。在其他细菌中，另一个受调节的蛋白质降解机器Clp的破坏导致了死亡。因此，抑制或强制激活分室蛋白酶可能代表一种新的抗感染策略。在我们最近对1600种加帽二肽的筛选中，我们鉴定了一种先导化合物，该化合物对结核分枝杆菌蛋白酶体的抑制作用强于对人类蛋白酶体的抑制作用。抑制剂与一氧化氮协同作用对非复制型结核分枝杆菌具有杀菌作用。使用竞争分析，我证实了二肽穿透分枝杆菌并抑制其中的蛋白酶体。在此应用中，我们将扩展我们的先导化合物到一个小的重点化合物库，其设计和合成的指导下，底物分析，结构分析，分枝杆菌杀菌活性，和代谢稳定性。