Blocking cationic antimicrobial peptide-resistance in Pseudomonas aeruginosa

阻断铜绿假单胞菌的阳离子抗菌肽耐药性

• 批准号: 9072275
• 负责人: Laura C. Miller Conrad
• 金额: $ 9.67万
• 依托单位: SAN JOSE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9072275
• 关键词: Antibiotic Resistance; Antibiotics; Antimicrobial Cationic Peptides; Area; Bacteria; Bacterial Drug Resistance; Bacterial Infections; Binding; Binding Sites; Biological Assay; C-terminal; Calorimetry; Carbohydrates; Carboxy-Lyases; Cells; Characteristics; Charge; Chemicals; Colistin; Combined Modality Therapy; Computer Simulation; Decarboxylation; Dissociation; Drug resistant Pseudomonas aeruginosa; Electrostatics; Enzymes; Exhibits; Foundations; Funding; Generations; Goals; Incidence; Kinetics; Knowledge; Lead; Length; Libraries; Lipid A; Lipids; Lipopolysaccharides; Longitudinal Studies; Masks; Mass Spectrum Analysis; Membrane; Modeling; Modification; Motivation; Multi-Drug Resistance; N-terminal; Operon; Pathway interactions; Permeability; Predisposition; Process; Property; Proteomics; Pseudomonas aeruginosa; Public Health; Research; Research Project Grants; Resistance; Resort; Science; Site; Structure; Structure-Activity Relationship; Students; Testing; Titrations; Underrepresented Groups; United States National Institutes of Health; Uridine Diphosphate Glucuronic Acid; analog; bacterial resistance; base; carbapenem-resistant Enterobacteriaceae; computer studies; design; experience; glycosylation; high throughput screening; inhibitor/antagonist; inorganic phosphate; multidrug-resistant Pseudomonas aeruginosa; overexpression; oxidation; pathogen; prevent; public health relevance; research study; resistant strain; small molecule; small molecule inhibitor; trend; uptake

 DESCRIPTION (provided by applicant): The increasing incidence of antibiotic resistance hampers our ability to effectively treat bacterial infections. The situation is especially dire for bacteria like Pseudomonas aeruginosa, which have limited treatment options. Cationic antimicrobial peptides (CAPs) are currently used as last resort treatments for multidrug resistant P. aeruginosa. Alarmingly, CAP-resistant strains have been encountered. To extend the utility of CAPs, the research project proposes to develop small molecule inhibitors of the resistance pathway in P. aeruginosa that can be used in a combination therapy along with a CAP. P. aeruginosa becomes resistant to CAPs by modifying the lipids of its outer membrane with carbohydrates, decreasing the overall negative charge of the membrane, and preventing the association and cell entry of the positively-charged CAP. The research proposes to inhibit ArnA, the first committed enzyme of the modification pathway. We will expand upon our initial ArnA inhibitors using a focused library of compounds structurally related to the initial hit. The impact of the structure of the small molecules on their ability to inhibit ArnA will then be analyzed (Aim 1). Inhibition of ArnA should prevent the remodeling of the outer membrane, forcing P. aeruginosa to maintain a negatively-charged outer membrane. The charge state of the membrane after inhibitor treatment will be characterized, and modifications to lipid A will be directly analyzed by mass spectrometry (Aim 2). The dissociation constant (Kd) of top inhibitors and the type of inhibition exhibited will be identified in a set of binding and kinetics experiment (Aim 3). Results from Aims 1 and 3 will guide the design and synthesis of a second set of inhibitors that aim to have even better potency and pharmacological properties. The long-term goal of the project is to develop a combination therapy that can be used to treat not only drug-resistant P. aeruginosa, but other gram-negative pathogens of concern like carbapenem-resistant Enterobacteriaceae.

 描述（由申请人提供）：抗生素耐药性的发生率不断增加，阻碍了我们有效治疗细菌感染的能力。情况尤其严重， 细菌，如铜绿假单胞菌，其治疗选择有限。阳离子抗菌肽（CAP）目前被用作多重耐药铜绿假单胞菌的最后手段治疗。令人担忧的是，已经遇到了CAP耐药菌株。为了扩大CAP的效用，该研究项目提出开发铜绿假单胞菌耐药途径的小分子抑制剂，其可与CAP一起沿着用于联合治疗。铜绿假单胞菌通过用碳水化合物修饰其外膜的脂质、减少膜的总体负电荷并阻止带正电荷的CAP的缔合和细胞进入而变得对CAP具有抗性。该研究提出抑制修饰途径的第一个关键酶ArnA。我们将扩大我们最初的ArnA抑制剂使用一个集中的化合物库结构相关的初始命中。的影响 然后将分析小分子的结构对它们抑制ArnA的能力的影响（Aim 1）。抑制ArnA应该防止外膜的重塑，迫使铜绿假单胞菌维持带负电荷的外膜。将表征抑制剂处理后膜的电荷状态，并通过质谱法直接分析脂质A的修饰（目的2）。将在一组结合和动力学实验（目标3）中确定顶级抑制剂的解离常数（Kd）和表现出的抑制类型。目标1和3的结果将指导第二组抑制剂的设计和合成，旨在具有更好的效力和药理学特性。该项目的长期目标是开发一种联合疗法，不仅可用于治疗耐药铜绿假单胞菌，还可用于治疗其他革兰氏阴性病原体，如耐碳青霉烯类肠杆菌科。