Selective modulation of bacterial chaperonins by targeting novel small molecule binding sites

通过靶向新的小分子结合位点选择性调节细菌伴侣蛋白

• 批准号: 9471392
• 负责人: Steven Michael Johnson
• 金额: $ 43.41万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9471392
• 关键词: Acinetobacter baumannii; Adverse effects; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Bacteria; Bacterial Antibiotic Resistance; Bacterial Infections; Binding; Binding Sites; Biochemical; Biological; Biophysics; Cells; Centers for Disease Control and Prevention (U.S.); Characteristics; Communicable Diseases; Complex; Data; Development; Distal; Enterobacter; Enterococcus faecium; Escherichia coli; Exhibits; Future; Goals; Human; In Vitro; Incidence; Infection; Infectious Agent; Klebsiella pneumonia bacterium; Laboratories; Lead; Literature; Mediating; Medical Care Costs; Mitochondria; Molecular; Molecular Conformation; Molecular Machines; Molecular Probes; Morbidity - disease rate; Multiple Bacterial Drug Resistance; Nucleotides; Pathway interactions; Peptides; Process; Program Development; Proteins; Pseudomonas aeruginosa; Research; Resistance; Risk; Series; Site; Staphylococcus aureus; Structure; Superbug; System; Tissues; Toxic effect; Translating; Treatment Efficacy; United States; X-Ray Crystallography; bactericide; base; biophysical analysis; chaperonin; combat; drug development; drug resistant pathogen; experimental study; functional loss; high throughput screening; inhibitor/antagonist; innovation; lead candidate; mortality; mutant; novel; novel therapeutics; outcome forecast; pathogen; proteostasis; recruit; scaffold; small molecule; small molecule inhibitor; societal costs

PROJECT SUMMARY: The growing incidences of antibiotic resistance is epitomized by the emergence of six multi-drug resistant bacteria referred to as the “ESKAPE” pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. Without research to develop new antibiotics that are effective against these drug resistant pathogens, we risk regressing to a pre-antibiotic era where infections were a leading cause of morbidity and mortality. To counter this threat, the long-term goal of this research is to develop new antibiotics that function by targeting bacterial GroEL chaperonin systems. GroEL is a centralized molecular machine that maintains the proper structure and function of hundreds of other proteins. Thus, targeting this one molecular machine will have the cascading effect of inhibiting hundreds of proteins at once, the functional losses of which bacteria will not be able to recover from. A caveat to this strategy is that human cells have a mitochondrial counterpart, called HSP60, and there remains the possibility of inhibitor cross-talk that could lead to toxic effects on host tissues. The central hypothesis is that the structural and functional divergence between bacterial and mammalian chaperonins, as well as other mammalian proteins, will allow the selective targeting of small molecule inhibitors for GroEL and bacteria without toxic side effects to human cells. This hypothesis has been formulated on the basis of well-established findings on chaperonin structure and function presented in the literature, and preliminary data for chaperonin inhibitors produced in the applicants' laboratories. In particular, human HSP60 functions as a single-ring oligomer, which removes many of the allosteric transitions that regulate the function of double-ring bacterial GroEL. In addition, preliminary data suggest there are multiple distinct binding sites on bacterial GroEL that compounds can interact with to block chaperonin function. Thus, the possibility of small molecules targeting these unique binding sites to selectively inhibit bacterial GroEL over HSP60 and other human proteins is high. The overall objective of this proposal is to identify these unique allosteric binding sites, elucidate the structural/functional mechanisms of action for molecules binding to these sites, and define the selectivity profiles for site-specific inhibitors in vitro and in cells. The rationale for the proposed studies is that delineating the precise structural/functional mechanisms of action of chaperonin inhibitors will permit the rational development GroEL-targeting antibiotic candidates. The approach is innovative because it proposes a unique and unexplored strategy of exploiting proteostasis machinery – specifically GroEL chaperonins – for killing infectious bacteria. Without a fundamental shift in strategy for treating infectious diseases, antibiotic resistance will continue to rise and the prognosis for surviving infection by these superbugs will continue to worsen. Therefore, the proposed studies will have significant impact because the research findings will open novel therapeutic strategies for a broad range of intractable infectious diseases.

项目摘要：六种抗生素耐药性的发电不断增长。 多药抗性细菌称为“ eskape”病原体：粪肠球菌，葡萄球菌 金黄色葡萄球菌，klebsiella肺炎，baumannii，假单胞菌铜绿和肠杆菌 物种。没有研究以开发有效抵抗这些耐药病原体有效的新抗生素的研究， 我们有可能回归到抗生素前时代，其中感染是发病率和死亡率的主要原因。到 应对这一威胁，这项研究的长期目标是开发新的抗生素来通过靶向来起作用 细菌凹槽链蛋白系统。凹槽是一种集中式分子机器，可维护适当的 其他数百种蛋白质的结构和功能。那是针对这台分子机的 一次抑制数百种蛋白质的级联效应，其功能损失不会是 该策略的警告是，人类细胞具有线粒体对应物，称为 HSP60，并且仍有抑制剂串扰的可能性，可能会对宿主组织产生毒性作用。 中心假设是细菌与哺乳动物之间的结构和功能差异 伴侣蛋白以及其他哺乳动物蛋白将允许选择性靶向小分子抑制剂 对于没有毒性副作用的凹槽和细菌。该假设已在 关于文献中介绍的链蛋白结构和功能的完善发现的基础， 申请人实验室中产生的伴侣蛋白抑制剂的初步数据。特别是人类HSP60 充当单环寡聚物，它去除了调节功能的许多变构转换 双环细菌凹槽的。此外，初步数据表明在 化合物可以与伴侣蛋白功能相互作用的细菌凹槽。那很小的可能性 针对这些独特结合位点的分子，可有选择地抑制HSP60和其他的细菌凹槽 人蛋白很高。该提案的总体目的是确定这些独特的变构结合位点， 阐明与这些位点结合的分子的作用的结构/功能机制，并定义 位点特异性抑制剂体外和细胞的选择性谱。拟议研究的理由是 描述链蛋白抑制剂的确切结构/功能机制，将允许 理性开发牙龈靶向抗生素候选者。这种方法是创新的，因为它提出了 利用蛋白质量机制（特别是凹槽伴侣蛋白）的独特而意外的策略 - 杀死 传染性细菌。没有治疗传染病的策略的根本转变，抗生素耐药性 这些超级细菌的生存感染将继续上升，并将继续担心。 因此，拟议的研究将产生重大影响，因为研究结果将开放新颖 针对多种顽固的传染病的治疗策略。