Elucidating the membrane properties regulating antimicrobial peptidebinding to bacterial vesicles

阐明调节抗菌肽与细菌囊泡结合的膜特性

• 批准号: 10796034
• 负责人: Nathan J. Wittenberg
• 金额: $ 45.7万
• 依托单位: LEHIGH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10796034
• 关键词: Affect; Affinity; Antibiotics; Bacteria; Basic Science; Binding; Binding Proteins; Biochemical; Biogenesis; Biological Assay; Biophysics; Cell membrane; Cells; Characteristics; Charge; Collaborations; Communication; Critical Thinking; Development; Effectiveness; Excision; Foundations; Future; Goals; Gram-Negative Bacteria; Growth; Heterogeneity; Immune response; Infection; Lipids; Lipopolysaccharides; Liposomes; Measurement; Membrane; Membrane Proteins; Methods; Microscopy; Mission; Modeling; National Institute of General Medical Sciences; Nature; Parents; Peptide Antibiotics; Peptides; Phospholipids; Play; Prevention; Process; Property; Proteins; Research; Research Personnel; Role; Surface; Surface Plasmon Resonance; Techniques; Testing; Therapeutic Agents; Variant; Vesicle; Visualization; Work; amphiphilicity; antimicrobial; antimicrobial peptide; biophysical techniques; cathelicidin antimicrobial peptide; chemical property; clinical translation; design; disease diagnosis; fluorescence imaging; graduate student; insight; light scattering; next generation; novel; periplasm; physical property; prevent; response; saturated fat; skills; student mentoring; undergraduate student; vesicular release; zeta potential

Project Summary Antimicrobial peptides (AMPs), such as LL-37, have been proposed as potential next-generation antibiotics due to their ability to bind to and disrupt the bacterial cell membrane. However, their use has been limited by several factors, including inactivation by binding to bacterial outer membrane vesicles (OMVs). OMVs are derived from the outer membrane (OM) of Gram-negative bacteria and therefore have a similar membrane composition as the OM. OMVs are heterogeneous in their physical and chemical properties, including size, charge, and lipid and protein composition, even among OMVs produced by the same parent bacterium. Traditional methods to study protein/peptide interactions with OMVs use bulk measurements, which result in ensemble averages that can obscure the influence OMV heterogeneity has on these interactions. We have developed several approaches that enable us to study protein-lipid interactions in OMVs on single-vesicle and subpopulation levels, which we will use in this project to uncover the specific properties that regulate LL-37 binding to OMVs. We will first use liposomes with controlled compositions to identify the roles of vesicle size, charge, lipid saturation, and LPS composition in LL-37 binding. Next, we will use OMVs with varying sizes and charges to relate LL-37 affinity to the OMVs’ ability to protect bacterial cells from the activity of LL-37. Finally, we will investigate how the properties of OMVs change upon exposure of the bacteria to LL-37 and how these changes affect LL-37 binding to OMVs. Undergraduate and graduate students will be highly involved in all of the proposed studies, and the Investigators are committed to mentoring these students to maximize their development of technical, critical thinking, and communication skills. We anticipate that the results generated from this project will inform the future design of more effective AMPs.

项目概要 抗菌肽 (AMP)，例如 LL-37，已被提议作为潜在的下一代 抗生素，因为它们能够结合并破坏细菌细胞膜。然而，它们的使用已 受到多种因素的限制，包括通过与细菌外膜囊泡结合而失活 （OMV）。 OMV 源自革兰氏阴性菌的外膜 (OM)，因此 具有与 OM 相似的膜成分。 OMV 的物理和结构是异质的 化学特性，包括大小、电荷、脂质和蛋白质组成，甚至在 OMV 中也是如此 由同一亲本细菌产生。研究蛋白质/肽相互作用的传统方法 OMV 使用批量测量，这会导致整体平均值掩盖 OMV 的影响 异质性对这些相互作用有影响。我们开发了几种方法，使我们能够研究 OMV 中单囊泡和亚群水平上的蛋白质-脂质相互作用，我们将在本研究中使用 项目旨在揭示调节 LL-37 与 OMV 结合的特定特性。我们首先使用脂质体 通过控制成分来确定囊泡大小、电荷、脂质饱和度和 LPS 的作用 LL-37 结合中的组成。接下来，我们将使用不同大小和电荷的 OMV 来关联 LL-37 与 OMV 保护细菌细胞免受 LL-37 活性影响的能力的亲和力。最后，我们将调查 当细菌暴露于 LL-37 时，OMV 的特性如何发生变化以及这些变化是如何发生的 影响 LL-37 与 OMV 的结合。本科生和研究生将高度参与所有的工作 拟议的研究，研究人员致力于指导这些学生最大限度地发挥他们的能力 技术、批判性思维和沟通技巧的发展。我们预计结果 该项目产生的结果将为未来设计更有效的 AMP 提供信息。