DEVELOPMENT OF NEW LIPID A BINDING AGENTS

新型脂质A结合剂的开发

• 批准号: 6181201
• 负责人: PAUL B SAVAGE
• 金额: $ 15.38万
• 依托单位: BRIGHAM YOUNG UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2003-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6181201
• 关键词: Escherichia coli; analog; antibiotics; binding proteins; bioassay; cholates; cyclic compound; drug design /synthesis /production; endotoxins; glycolipids; intermolecular interaction; lipopolysaccharides; microorganism culture

DESCRIPTION: Sepsis affects the lives of hundreds of thousands of people each in the U.S. Sepsis caused by Gram-negative bacteria results from adverse host immune response to the Lipid A (LA) portion of endotoxin. Compounds with high affinity for LA, including polymyxin B (PMB) and derivatives, are capable of detoxifying LA nd protection a host against sepsis. By binding LA, these compounds also sensitize Gram-negative bacteria to hydrophobic antibiotics. However, therapeutic use of PMB is limited due to its toxicity. The aim of this research is to develop small molecules capable of strong and selective associating with LA for use in treatment of sepsis and as means of fighting bacterial infection. Taking the interactions of PMB with LA as a model, this research focuses on the preparation of simple compounds, based on cholic acid scaffolding, capable of mimicking the LA-binding behavior of PMB but lacking the toxicity of the antibiotic. Simple cholic-acid based LA binders will present many advantages over reported LA binding molecules including: ease of preparation and derivatization, greater control over biological stability, and potential oral bioavailablity. Cholic acid derivatives were designed to mimic a conformation of PMB believed to be important in its association with LA. Preliminary experiments with cholic acid derivatives demonstrate their ability to sensitize Gram- negative bacteria to hydrophobic antibiotics, a behavior of LA binding agents. Optimization of LA-binding characteristics will be achieved by preparing libraries of compounds made up by amino acids linked to cholic acid scaffold. The libraries will be screened for LA binding using affinity chromatography. The affinity chromatography stationary phase will be made up of LA immobilized through hydrophobic interactions of C18- silica particles or polystyrene beads. The types of amino acids in effective LA binders will be determined via mass spectroscopy. New LA-binding agents will be tested for the ability to sensitize Gram- negative bacteria to hydrophobic antibiotics and/or inhibit the effects of LA on human monocytes (specifically interleukin 1b production). Association of PMB and the new LA-binders with LA and LA derivatives will be compared using microtitration calorimetry.

描述：败血症影响数十万人的生活 在美国，由革兰氏阴性菌引起的败血症都是由 对内毒素脂质 A (LA) 部分的不良宿主免疫反应。 对 LA 具有高亲和力的化合物，包括多粘菌素 B (PMB) 和 衍生物，能够解毒 LA 并保护宿主免受 败血症。 通过结合 LA，这些化合物还可使革兰氏阴性菌敏感 细菌对疏水性抗生素。 然而，PMB 的治疗用途 由于其毒性而受到限制。 这项研究的目的是开发 能够与 LA 强选择性结合的小分子 用于治疗败血症和作为对抗细菌感染的手段。 以PMB与LA的相互作用为模型，本研究重点 基于胆酸的简单化合物的制备 支架，能够模仿 PMB 的 LA 结合行为，但 缺乏抗生素的毒性。 单纯胆酸基 LA 结合剂将比报道的 LA 结合分子具有许多优势 包括：易于制备和衍生化，更好地控制 生物稳定性和潜在的口服生物利用度。 胆酸 衍生物被设计来模仿 PMB 的构象，据信 它与洛杉矶的联系很重要。初步实验 胆酸衍生物证明了它们使革兰氏阴性菌致敏的能力 疏水性抗生素阴性细菌，LA 结合行为 代理。 LA 结合特性的优化将通过以下方式实现 制备由与胆酸连接的氨基酸组成的化合物库 酸支架。 将使用以下方法筛选文库的 LA 结合 亲和色谱法。 亲和色谱固定相 将由通过疏水相互作用固定的 LA 组成 C18-二氧化硅颗粒或聚苯乙烯珠。 氨基酸的种类 有效的 LA 粘合剂中的含量将通过质谱法测定。 新的 LA 结合剂将被测试其致敏革兰氏阴性菌的能力。 细菌对疏水性抗生素呈阴性和/或抑制其作用 LA 对人类单核细胞的影响（特别是白细胞介素 1b 的产生）。 PMB 和新型 LA 粘合剂与 LA 和 LA 衍生物的结合 将使用微量滴定量热法进行比较。