Functionally Selective RecA Inhibitors to Probe Bacterial Genetic Recombination

功能选择性 RecA 抑制剂探测细菌基因重组

• 批准号: 8109283
• 负责人: Justin James Richards
• 金额: $ 3.83万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8109283
• 关键词: ATP phosphohydrolase; Address; Adjuvant; Affect; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Area; Attenuated; Bacteria; Bacterial Drug Resistance; Bacterial Infections; Behavior; Biochemical; Biological; Biological Assay; Biological Process; Cell physiology; Cells; Characteristics; Chemosensitization; Combination Drug Therapy; Communicable Diseases; Data; Development; Disease; Escherichia coli; Evaluation; Experimental Designs; Foundations; Generations; Genes; Genetic Recombination; Goals; Gram-Negative Bacteria; Gram-Positive Bacteria; Infection; Inhibitory Concentration 50; Investigation; Knowledge; Lead; Libraries; Life; Light; Lipopolysaccharides; Mediating; Molecular Conformation; Neisseria; Pathogenicity; Pathway interactions; Permeability; Process; Property; Protein Conformation; Proteins; Public Health; Rec A Recombinases; Relative (related person); Research; Role; Running; SOS Response; Screening procedure; Sexually Transmitted Diseases; Species Specificity; Staging; Streptococcus pneumoniae; System; Therapeutic Index; analog; antineoplastic antibiotics; bacterial genetics; bactericide; base; biodefense; biothreat; chemotherapy; combat; design; drug development; global health; high throughput screening; improved; inhibitor/antagonist; killings; mutant; novel; pathogen; pathogenic bacteria; prevent; programs; protein function; prototype; public health relevance; research study; small molecule; therapeutic target; transmission process

DESCRIPTION (provided by applicant): Antibiotic resistance is an ever-increasing problem for modern chemotherapy of bacterial infectious diseases. In light of the limited pipeline of new antibacterials, drug-resistant pathogens are a clear and urgent danger to public health and national biodefense. Recent evidence suggests that the bacterial RecA protein's functions, which are carried out through two distinct protein conformation states (termed A and P), allow bacteria to overcome or adapt to antibacterial actions. Because of the inherent complexity of these processes involving interconnected networks of genes and gene products, recA mutants are pleiotropic. We hypothesize that functionally selective small-molecule probes capable of modulating predetermined RecA functions would be useful in teasing apart the relative contributions of its myriad activities to key biological processes involved in bacterial survival or adaptation to antibacterial therapies. Moreover, small-molecule inhibitors of RecA may serve as leads for the development of combination chemotherapies for bacterial infectious diseases. A prototypical RecA inhibitor was previously discovered from a screen of a multi- thousand compound library. This represents the first small molecule with demonstrated inhibitory activity in live Escherichia coli. Furthermore, the prototype demonstrated functional selectivity by only inhibiting RecA P-state activities. The purpose of the proposed research is to initiate a program that utilizes the prototypical inhibitor as a platform for the design, synthesis, and biological evaluation of analogous RecA inhibitors that selectively modulate recombinogenic processes in pathogenic bacteria. Specifically, we aim to (1) evaluate the abilities of a first-generation pilot library of prototype analogues to inhibit genetic recombination processes in pathogenic bacteria; (2) synthesize and biochemically evaluate second-generation analogues to identify improved RecA inhibitors; (3) characterize second-generation RecA inhibitors against E. coli utilizing robust microbiological and biochemical assays; and (4) characterize second-generation RecA inhibitors against Neisseria gonnorhoea and Streptococcus pneumonia. As functionally selective P-state inhibitors, these small-molecule probes will allow us to identify and characterize specific roles that are ascribed to the A- and P-state conformations of RecA in the development and transmission of antibiotic resistance. Additionally, we expect the research program to serve as platform enabling the exploitation of RecA as a therapeutic target. Realization of the goals outlined in this proposal will have a significant impact on the research areas of bacterial infections (how bacteria adapt to antibacterial actions), sexually transmitted diseases (study of genetic recombination in N. gonnorhoea), and overall global health (study of various disease states from S. pneumonia infections). Furthermore, the research should make important contributions to the fields of drug development (identification of non-classical targets, potentiation of known antibacterials) and biodefense development. PUBLIC HEALTH RELEVANCE: Antibiotic resistance is an ever-increasing problem for modern chemotherapy of bacterial infectious diseases. In light of the limited pipeline of new antibacterials, drug-resistant pathogens are a clear and urgent danger to public health and national biodefense. The bacterial RecA protein is an emerging target for adjuvants for antibiotic chemotherapy that attenuate the development and transmission of antibiotic resistance genes and increase the antibiotic therapeutic index. It is envisioned that the proposed plan will lead to small-molecule probes that selectively inhibit predetermined functions of the RecA protein in live bacteria, thus affording greater understanding of the protein's roles in various aspects of bacterial pathogenicity - including the de novo development and transmission of antibiotic resistance genes. This new knowledge will significantly impact approaches to sexually transmitted disease, biodefense, and overall global public health related to infectious disease. The research platform will also increase the efficiency of the discovery of small- molecule effectors that address the urgent unmet need to overcome antibiotic resistance in biothreat and other pathogenic bacteria.

描述（由申请人提供）：抗生素耐药性是现代化学疗法对细菌感染疾病的不断增长的问题。鉴于新抗菌药物的有限管道，耐药的病原体是对公共卫生和民族生物形式的明显而紧迫的危险。最近的证据表明，细菌RECA蛋白的功能是通过两个不同的蛋白质构象（称为A和P）进行的，使细菌可以克服或适应抗菌作用。由于这些过程涉及基因和基因产物互连网络的固有复杂性，因此RECA突变体是多效性的。我们假设能够调节预定的RECA功能的功能性选择性的小分子探针将有助于嘲笑其无数活性对参与细菌存活或适应抗菌疗法的关键生物学过程的相对贡献。此外，RECA的小分子抑制剂可以作为开发细菌传染病联合化疗的铅。先前从数千种化合物库的屏幕上发现了典型的RECA抑制剂。这代表了在活大肠杆菌中具有抑制活性的第一个小分子。此外，该原型仅通过抑制RECA P-State活性来表现出功能选择性。拟议研究的目的是启动一个程序，该程序利用原型抑制剂作为设计，合成和生物学评估的平台，对类似RECA抑制剂进行选择性调节致病细菌中重组过程的类似RECA抑制剂。具体而言，我们旨在（1）评估原型类似物的第一代试验库以抑​​制致病细菌的遗传重组过程的能力； （2）合成和生物化学评估第二代类似物以鉴定改进的RECA抑制剂； （3）表征第二代RECA抑制剂针对大肠杆菌利用强大的微生物学和生化测定； （4）表征第二代RECA抑制剂针对贡诺霍亚和肺炎链球菌的抑制剂。作为功​​能性选择性的P型抑制剂，这些小分子探针将使我们能够识别并表征归因于RECA在抗生素耐药性的开发和传播中归因于A的A和P状态构象。此外，我们预计该研究计划将作为实现RECA作为治疗目标的平台。该提案中概述的目标的实现将对细菌感染的研究领域产生重大影响（细菌如何适应抗菌作用），性传播疾病（研究N. gonnorhoea中的遗传重组）和整体全球卫生（对多种疾病的研究状态）。此外，这项研究应为药物开发领域（非古典靶标，已知抗菌剂的增强）和生物污染物发育做出重要贡献。 公共卫生相关性：抗生素耐药性是现代细菌传染病化学疗法的不断增长的问题。鉴于新抗菌药物的有限管道，耐药的病原体是对公共卫生和民族生物形式的明显而紧迫的危险。细菌RECA蛋白是抗生素化学疗法佐剂的新兴靶标，可减弱抗生素耐药基因的发展和传播并增加抗生素治疗指数。可以预见的是，拟议的计划将导致小分子探针有选择地抑制活细菌中RECA蛋白的预定功能，从而对蛋白质在细菌致病性的各个方面的作用有更深入的了解 - 包括Nevo发育和抗生素抗性基因的传播。这些新知识将显着影响与传染病有关的性传播疾病，生物探讨和整体全球公共卫生的方法。研究平台还将提高发现小分子效应子的效率，这些效应子解决了在生物治疗和其他致病细菌中克服抗生素耐药性的紧迫需求。