Physical and Chemical Properties of Lipid Rafts

脂筏的理化性质

• 批准号: 6742522
• 负责人: Kenneth A Jacobson
• 金额: $ 31.01万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6742522
• 关键词: bioimaging /biomedical imaging; biological signal transduction; chemical property; detergents; fluorescence microscopy; fluorescence spectrometry; light microscopy; lipid bilayer membrane; membrane activity; membrane model; membrane proteins; membrane structure; particle; physical property; protein transport; tissue /cell culture

DESCRIPTION (provided by applicant): Lipid rafts are an important new concept in biomembranes but one that remains controversial because at this juncture the cell biologist's definitions of rafts--detergent resistant membranes and cholesterol extraction-induced abrogation of raft function--have no unambiguous cellular correlate as determined by microscopic methods. In Specific Aim I, we will compare the results of sophisticated and highly appropriate light microscopic methods applied to living cells to the predictions of three extreme models for lipid microdomains in cell membranes. The methods include fluorescence correlation spectroscopy, single particle tracking, single dye tracing, and single domain imaging. The results of the comparison between models and experiments should lead to a considerable refinement in our views of lipid microdomains on cell surfaces. Specific Aim II is directed towards exploring the physical and chemical properties of rafts that could provide functionality. Transbilayer communication and why certain molecular components reside in rafts are key unanswered questions in the field today. Using asymmetric planar supported bilayers, we will determine how liquid-ordered domains on the outer monolayer communicate with the inner monolayer to facilitate raft-mediated signal transduction processes. The factors that determine partitioning of various raft-preferring and cross-linked membrane components into liquid-ordered domains and the competition between raft-resident components for sites in these domains will also be defined. Because the concept of raft detergent resistance is so crucial to the concept, we will image the action of various detergents on raft domains existing in planar supported membranes using fluorescence microscopy.

描述（由申请人提供）：脂筏是生物膜中的一个重要的新概念，但仍然存在争议，因为此时细胞生物学家对脂筏的定义——耐洗涤剂膜和胆固醇提取引起的筏功能废除——没有明确的定义。通过显微镜方法确定的细胞相关性。在特定目标 I 中，我们将比较应用于活细胞的复杂且高度合适的光学显微镜方法的结果与细胞膜中脂质微区的三个极端模型的预测。这些方法包括荧光相关光谱、单粒子追踪、单染料追踪和单域成像。模型和实验之间的比较结果应该会大大改进我们对细胞表面脂质微结构域的看法。具体目标 II 旨在探索可提供功能的筏的物理和化学特性。跨双层通讯以及为什么某些分子成分驻留在筏中是当今该领域尚未解答的关键问题。使用不对称平面支撑双层，我们将确定外单层上的液体有序域如何与内单层通信，以促进筏介导的信号转导过程。还将定义决定各种筏偏好和交联膜组分划分成液体有序域的因素以及筏驻留组分之间对这些域中位点的竞争。由于筏去污剂抗性的概念对该概念至关重要，因此我们将使用荧光显微镜对平面支撑膜中存在的筏域上各种去污剂的作用进行成像。