Understanding how the S. Epidermidis Biofilm Proteins Aap and AtlE Interact with Surfaces

了解表皮葡萄球菌生物膜蛋白 Aap 和 AtlE 如何与表面相互作用

• 批准号: 9573414
• 负责人: Nicholas C Fitzkee
• 金额: $ 24.16万
• 依托单位: MISSISSIPPI STATE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9573414
• 关键词: Address; Adhesions; Adsorption; Antibiotic Resistance; Autolysin; Bacteria; Bacterial Attachment Site; Behavior; Binding; Binding Proteins; Biological Assay; Cell Wall; Cell surface; Cells; Centers of Research Excellence; Charge; Chemicals; Contracts; DNA; Data; Deuterium; Development; Excision; Exposure to; Extracellular Matrix; Extracellular Matrix Proteins; Extracellular Protein; Fibrinogen; Fibronectins; Genus staphylococcus; Glass; Homologous Gene; Hospitals; Hydrogen; Immune response; Infection; Label; Lead; Length; Measurement; Mediating; Medical Device; Membrane Proteins; Methods; Microbial Biofilms; Modeling; Monitor; Mutagenesis; NMR Spectroscopy; Nature; Pathway interactions; Patients; Plasma Proteins; Polyethylene Glycols; Polysaccharides; Polystyrenes; Prevention; Property; Protein Family; Protein Inhibition; Proteins; Regulation; Relaxation; Scientist; Silicon Dioxide; Source; Staphylococcus aureus; Staphylococcus epidermidis; Streptococcus; Structure; Surface; System; Techniques; Testing; Time; Titania; Tweens; Work; base; biophysical tools; design; economic cost; healthcare-associated infections; innovation; insight; medical implant; nanoparticle; novel; novel strategies; pathogen; pathogenic bacteria; prevent; surface coating

The first step in biofilm formation is bacterial attachment to a surface. This attachment is mediated by components on the cell surface as well as the surface itself. Understanding the chemical interactions involved in attachment is an important part of preventing biofilm-related illness. Several proteins have been implicated in bacterial attachment and biofilm initiation, but their behavior on surfaces is poorly understood. Moreover, few experimental techniques exist that are able to characterize surface-bound protein behavior. This project investigates the properties of two biofilm-related proteins in Streptococcus epidermidis, Aap and AtlE, as they interact with surfaces. Recently developed approaches using NMR spectroscopy will be employed to study the structure and orientation of these proteins on various nanoparticle surfaces. Nanoparticles offer a significant increase in surface to volume ratio compared to macroscopic surfaces, and recent evidence suggests that nanoparticle curvature does not substantially alter the nature of protein-surface interactions. This makes nanoparticles an attractive system for studying protein surface interactions. This work uses nanoparticles are used to model surfaces made of glass and plastic, surfaces commonly used in implanted medical devices, as well as surfaces exposed to host extracellular matrix proteins. Three specific aims are proposed: (1) To identify the structural mode of interaction between biofilm-related proteins and surfaces, NMR-based hydrogen deuterium exchange, chemical labeling, and relaxation measurements will be applied to Aap and AtlE domains bound to surfaces. (2) To understand how biofilm protein competition influences surface binding, mixtures of Aap and AtlE domains will be studied, monitoring simultaneous surface binding in real time. (3) To determine how biofilm proteins bind to chemically passivated surfaces, we will explore the protein properties (e.g. charge, size) of Aap and AtlE domains that modulate binding to surfaces coated with PEG and Tween-20. Treatment with PEG is a common strategy for reducing protein binding, but this does not prevent binding entirely, and the reason why is not clear. Biofilms represent a major cause of hospital- associated infection in the US, and this project will lead to a better understanding of the early stages of bacterial attachment. This project applies novel and innovative techniques to study the chemical basis of adsorption of Aap and AtlE, and the results will be directly relevant to other bacterial biofilms as well. The mechanistic details revealed by this study will be useful in understanding how biofilms form, and such insights could ultimately lead to better approaches for inhibiting the formation of biofilms on surfaces.

生物膜形成的第一步是细菌附着到表面。这种依恋是由 细胞表面的成分以及表面本身。了解所涉及的化学相互作用 附着是预防生物膜相关疾病的重要组成部分。多种蛋白质与此有关 细菌附着和生物膜启动，但人们对它们在表面的行为知之甚少。而且，很少有 现有的实验技术能够表征表面结合蛋白的行为。这个项目 研究表皮链球菌中两种生物膜相关蛋白 Aap 和 AtlE 的特性，因为它们 与表面相互作用。最近开发的使用核磁共振波谱的方法将用于研究 这些蛋白质在各种纳米颗粒表面上的结构和方向。纳米粒子提供了重要的 与宏观表面相比，表面与体积之比增加，最近的证据表明 纳米颗粒的曲率不会显着改变蛋白质-表面相互作用的性质。这使得 纳米粒子是研究蛋白质表面相互作用的一个有吸引力的系统。这项工作使用的纳米颗粒是 用于对玻璃和塑料制成的表面进行建模，这些表面常用于植入式医疗设备，例如 以及暴露于宿主细胞外基质蛋白的表面。提出了三个具体目标： (1) 基于 NMR 确定生物膜相关蛋白质和表面之间相互作用的结构模式 氢氘交换、化学标记和弛豫测量将应用于 Aap 和 AtlE 结构域与表面结合。 (2) 了解生物膜蛋白质竞争如何影响表面 结合，将研究 Aap 和 AtlE 结构域的混合物，实时监测同时表面结合 时间。 (3) 为了确定生物膜蛋白如何与化学钝化表面结合，我们将探索 Aap 和 AtlE 结构域的蛋白质特性（例如电荷、大小）调节与包被表面的结合 PEG 和 Tween-20。 PEG 处理是减少蛋白质结合的常见策略，但这并不 完全阻止绑定，其原因尚不清楚。生物膜是医院出现问题的一个主要原因 美国的相关感染，该项目将有助于更好地了解病毒的早期阶段 细菌附着。该项目应用新颖和创新的技术来研究化学基础 Aap 和 AtlE 的吸附，结果也将与其他细菌生物膜直接相关。这 这项研究揭示的机制细节将有助于理解生物膜是如何形成的，以及这些见解 最终可能会找到更好的方法来抑制表面生物膜的形成。