Expanding the genetic code of streptomycetes: a platform for new antibiotics

扩展链霉菌的遗传密码：新抗生素的平台

• 批准号: 8777767
• 负责人: Sean Alan Reed
• 金额: $ 5.15万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2016-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8777767
• 关键词: Actinobacteria class; Americas; Amino Acids; Amino Acyl-tRNA Synthetases; Antibiotic Resistance; Antibiotics; Antifungal Agents; Archaea; Bacteria; Bacterial Antibiotic Resistance; Bacterial Infections; Beta-glucuronidase; Binding; Biochemical; Biological; Biological Factors; Biology; Cell Line; Cells; Chemicals; Clinic; Clinical; Codon Nucleotides; Community Hospitals; Complex; Data; Development; Drug resistance; Effectiveness; Electronics; Engineering; Enzymes; Escherichia coli; Funding; Future; Gene Cluster; Genes; Genetic Code; Goals; Guanosine Triphosphate; Health; Human; Hydrolysis; Immunosuppressive Agents; Infection; Label; Ligase; Medical; Medicine; Methodology; Methods; Modeling; Modification; Molecular; Multi-Drug Resistance; Organism; Peptide antibodies; Pharmacologic Substance; Positioning Attribute; Post-Translational Protein Processing; Property; Proteins; Public Health; Randomized; Reporting; Research; Research Personnel; Resistance; Ribosomal RNA; Shapes; Site; Soil; Solubility; Streptomyces; Structure; System; Testing; Therapeutic; Thiostrepton; Toxic effect; Training; Transfer RNA; Translating; analog; base; chemical synthesis; clinically relevant; drug resistant bacteria; fighting; health application; human disease; improved; in vivo; innovation; insight; methicillin resistant Staphylococcus aureus; novel; novel strategies; public health relevance; pyrrolysine; scaffold; tool

DESCRIPTION (provided by applicant): The discovery and development of fundamentally new classes of antibiotics to treat bacterial infections has slowed dramatically. This is a critica problem to human health due to the emergence multi-drug resistant bacterial strains, which present a threat to both hospitals and communities at large. The long-term goal is to create new methods for studying the mechanisms leading to efficacy or resistance, while developing antibiotics that can overcome resistance. This application's objective is to site-specifically incorporate unnatural amino acids into ribosomally synthesized thiopeptide antibiotics produced by the soil bacteria, Streptomyces. The central hypothesis is that ribosomal incorporation of these unnatural amino acids will create a rapid and general method to study existing and future thiopeptide mechanisms of action, as well as drastically improve the pharmacological properties of thiopeptides for human clinical use. This contrasts with previous synthetic strategies, which have been hindered by the high molecular complexity of thiopeptides. The central hypothesis is based on the demonstrated utility of unnatural amino acids for the creation of biophysical and cell biological probes, biologically active peptide and antibody scaffolds, and improved medicinal bioconjugates. The rationale for this proposal is that understanding novel antibiotic thiopeptide mechanisms and creation of new thiopeptide antibiotics scaffolds has the potential to translate into new medicines to treat the roughly 2 million cases of drug-resistant bacterial infections reported each year. The central hypothesis will be tested with the following specific aims: 1) Elucidate berninamycin's antibiotic mechanism of action and 2) Identify improved analogues of thiopeptide GE37468. Insertion of unnatural amino acids into thiopeptides berninamycin will allow labeling studies to test the hypothesis that it possess a unique dual mode of action, and modification of GE37468's core scaffold will generate improved thiopeptides to test against multi-drug resistant bacterial strains. Incorporation of unnatural amino acids will be accomplished using established orthogonal aminoacyl- tRNA synthetase (aaRS)/tRNA pairs and known thiopeptide producing gene clusters into Streptomycetes. This approach is innovative because it combines both existing biosynthetic ribosomal machinery with chemical synthesis (unnatural amino acids) to produce thiopeptides with precisely engineered structure and reactivity. Significantly, this research stands to increase our understanding of novel antibiotic mechanisms, and create a new model for the creation of thiopeptide antibiotic analogues.

描述（由申请人提供）：用于治疗细菌感染的新型抗生素的发现和开发已显着放缓。由于多重耐药细菌菌株的出现，这对人类健康来说是一个关键问题，对医院和整个社区构成了威胁。长期目标是创造新的方法来研究导致疗效或耐药性的机制，同时开发可以克服耐药性的抗生素。本申请的目的是将非天然氨基酸位点特异性地掺入由土壤细菌链霉菌产生的核糖体合成的硫肽抗生素中。核心假设是，这些非天然氨基酸的核糖体掺入将创建一个快速和通用的方法来研究现有的和未来的硫肽作用机制，以及大大提高人类临床使用的硫肽的药理学特性。这与之前的合成策略形成对比，之前的合成策略受到硫肽的高分子复杂性的阻碍。中心假设是基于非天然氨基酸用于创建生物物理和细胞生物学探针、生物活性肽和抗体支架以及改进的药用生物缀合物的已证明的效用。这项提议的基本原理是，了解新型抗生素硫肽机制和创造新的硫肽抗生素支架有可能转化为新的药物，以治疗每年报告的大约200万例耐药细菌感染。中心假设将通过以下特定目的进行检验：1）阐明伯宁霉素的抗生素作用机制和2）鉴定硫肽GE 37468的改良类似物。将非天然氨基酸插入到硫肽berninamycin中将允许标记研究来测试其具有独特的双重作用模式的假设，并且GE 37468的核心支架的修饰将产生改进的硫肽以测试针对多药耐药细菌菌株。使用已建立的正交氨酰- tRNA合成酶（阿尔斯）/tRNA对和已知的硫肽产生基因簇将非天然氨基酸掺入链霉菌中。这种方法是创新的，因为它结合了现有的生物合成核糖体机制与化学合成（非天然氨基酸），以产生具有精确工程结构和反应性的硫肽。值得注意的是，这项研究增加了我们对新型抗生素机制的理解，并为硫肽抗生素类似物的产生创造了新的模型。