Small molecules for perturbing iron homeostasis in bacterial biofilms

扰乱细菌生物膜中铁稳态的小分子

• 批准号: 10573309
• 负责人: Mario Rivera
• 金额: $ 72.86万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10573309
• 关键词: Acinetobacter baumannii; Address; Affect; Affinity; Animal Model; Anti-Bacterial Agents; Anti-Infective Agents; Antibiotic Resistance; Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Bacteria; Binding; Binding Sites; Biology; Cell Death; Cell Survival; Cells; Chemicals; Chronic; Clinical; Complex; Cytosol; Drug Industry; Effectiveness; Elderly; Electron Transport; Environment; Escherichia; Generations; Genes; Gram-Negative Bacteria; Health care facility; Healthcare; Homeostasis; Immune response; Impairment; Infection; Invaded; Ions; Iron; Laser Scanning Confocal Microscopy; Lead; Long-Term Care; Maintenance; Mammalian Cell; Metabolism; Microbial Biofilms; Microbial Genetics; Modification; Multi-Drug Resistance; Mus; Mutation; Organic Synthesis; Patient Admission; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phenotype; Physiological; Predisposition; Proteins; Pseudomonas aeruginosa; Reaction; Resistance; Resistance development; Staphylococcus aureus; Structure; Synthesis Chemistry; Testing; Theft; Work; Wound Infection; Wound models; X-Ray Crystallography; analog; antibiotic tolerance; antimicrobial; bactericide; chronic wound; combat; cytotoxicity; deprivation; design; diabetic patient; drug development; drug discovery; experience; improved; in vivo; in vivo Model; inhibitor; insight; iron metabolism; medical schools; next generation; novel; pathogen; protein complex; protein protein interaction; rational design; research and development; resistant strain; small molecule; small molecule inhibitor; structural biology; synergism; tool; tool development; wound care

ABSTRACT Chronic wound care is especially complicated by the formation of bacterial biofilms, commonly by Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus. Biofilms are recalcitrant to antibiotic therapy, which is an important reason why chronic wound infections are so difficult to eradicate. There is a significant need to discover new strategies to combat biofilms. Bacterial iron homeostasis is a suitable novel target for developing anti-infectives because the host makes essential iron scarce to invading pathogens. Bacteria have evolved mechanisms to “steal” iron from their host, but these depend on well-regulated iron homeostasis. To disrupt bacterial iron homeostasis, we are targeting the iron storage protein BfrB and its physiological partner protein, Bfd, which are unique to bacteria. Our work has shown that BfrB regulates cytosolic iron concentrations by (a) oxidizing Fe2+ and storing up to ~3,000 Fe3+ ions in its internal cavity, and (b) forming a complex with Bfd to reduce Fe3+ in the internal cavity of BfrB and release Fe2+ to the cytosol for its incorporation in metabolism. Blocking the BfrB-Bfd complex in P. aeruginosa cells by deletion of the bfd gene perturbs iron homeostasis by triggering an irreversible accumulation of Fe3+ in BfrB and simultaneous cytosolic iron depletion, which leads to impaired biofilm maintenance and biofilm cell death. Our work also led to the discovery of proof-of-concept inhibitors of the BfrB-Bfd complex, which bind BfrB at the Bfd binding site, inhibit iron mobilization, and elicit biofilm cell death. The objectives of this application are to improve the proof-of-concept molecules into lead molecules, evaluate their antibacterial and antibiofilm effectiveness, and evaluate their potential drug suitability. Our interdisciplinary team includes expertise in chemical and structural biology of bacterial iron homeostasis (Rivera), organic synthesis and reaction mechanisms (Bunce), pharmaceutical industry research and development of anti-infectives (Reitz), X-ray crystallography in drug discovery (Lovell), microbial genetics (Chandler), and animal model of infection (Morici). The specific aims are: 1) Evolve proof-of-concept analogs into potent inhibitors of the BfrB-Bfd complex. This work will follow a systematic, iterative strategy of medicinal chemistry synthesis optimization that relies on crystal structures of inhibitor bound BfrB to design each new generation of inhibitors. 2) Asses the antibacterial effectiveness of inhibitors of the BfrB-Bfd complex and evaluate their potential drug suitability.

抽象的 细菌生物膜（通常是假单胞菌）的形成使慢性伤口护理变得尤其复杂 铜绿假单胞菌、鲍曼不动杆菌和金黄色葡萄球菌。生物膜对抗生素治疗有抵抗力， 这是慢性伤口感染难以根除的重要原因。有一个显着的 需要发现对抗生物膜的新策略。细菌铁稳态是一个合适的新靶点 开发抗感染药物是因为宿主使入侵的病原体缺乏必需的铁。细菌有 进化出从宿主“窃取”铁的机制，但这取决于良好调节的铁稳态。到 破坏细菌铁稳态，我们的目标是铁储存蛋白 BfrB 及其生理伙伴 蛋白质，Bfd，是细菌特有的。我们的工作表明 BfrB 调节胞质铁浓度 通过 (a) 氧化 Fe2+ 并在其内腔中储存多达约 3,000 个 Fe3+ 离子，以及 (b) 与 Bfd 形成复合物 还原 BfrB 内腔中的 Fe3+ 并将 Fe2+ 释放到细胞质中以参与代谢。 通过删除 bfd 基因来阻断铜绿假单胞菌细胞中的 BfrB-Bfd 复合物，从而扰乱铁稳态 触发 BfrB 中 Fe3+ 不可逆积累，同时胞质铁耗尽，从而导致 生物膜维持受损和生物膜细胞死亡。我们的工作还导致了概念验证的发现 BfrB-Bfd 复合物的抑制剂，在 Bfd 结合位点结合 BfrB，抑制铁动员，并引发 生物膜细胞死亡。该应用的目标是将概念验证分子改进为领先的 分子，评估其抗菌和抗生物膜有效性，并评估其潜在的药物适用性。 我们的跨学科团队包括细菌铁稳态的化学和结构生物学方面的专业知识 （Rivera）、有机合成与反应机理（Bunce）、制药工业研究与 抗感染药物的开发 (Reitz)、药物发现中的 X 射线晶体学 (Lovell)、微生物遗传学 （钱德勒）和感染动物模型（莫里奇）。具体目标是：1）发展概念验证类似物 转化为 BfrB-Bfd 复合物的有效抑制剂。这项工作将遵循系统的、迭代的医学策略 化学合成优化依赖于抑制剂结合 BfrB 的晶体结构来设计每个新的 抑制剂的产生。 2) 评估 BfrB-Bfd 复合物抑制剂的抗菌效果 评估其潜在的药物适用性。