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.

项目摘要 抗微生物肽（AMP），如LL-37，已被提出作为潜在的下一代 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 受到几个因素的限制，包括通过与细菌外膜囊泡结合而失活 （OMV）。OMV来源于革兰氏阴性菌的外膜（OM），因此 具有与OM相似的膜组成。OMV的物理和物理特性是异质的， 化学性质，包括大小，电荷，脂质和蛋白质组成，即使在OMV中 是由同一种细菌产生的研究蛋白质/肽相互作用的传统方法 OMV使用批量测量，这导致可以掩盖OMV影响的总体平均值 异质性对这些相互作用的影响。我们已经开发了几种方法，使我们能够研究 蛋白质-脂质相互作用在单囊泡和亚群水平上的OMV，我们将在这方面使用 该项目旨在揭示调节LL-37与OMV结合的特定特性。我们将首先使用脂质体 用受控的成分来确定囊泡大小、电荷、脂质饱和度和LPS的作用 LL-37结合中的组合物。接下来，我们将使用不同尺寸和电荷的OMV来关联LL-37 这与OMV保护细菌细胞免受LL-37活性影响的能力有关。最后，我们将调查 当细菌暴露于LL-37时，OMV的性质如何变化，以及这些变化如何 影响LL-37与OMV的结合。本科生和研究生将高度参与所有的 建议的研究，研究人员致力于指导这些学生，以最大限度地提高他们的 技术，批判性思维和沟通技巧的发展。我们预计， 该项目产生的信息将为今后设计更有效的AMP提供信息。