LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

描述（改编自摘要）：本实验室的主要重点是 确定脂质和蛋白质的结构是如何改变的， 一系列模型和天然膜的相互作用， 复杂性，以及这些结构修饰如何与功能相关。的 研究人员开发了FT-IR实验， 关于膜脂质构象和取向顺序的信息， 将这项技术应用于生理学相关的实验范例， 也就是说，在空气/水（A/W）界面处原位形成单分子层。这个实验，A 肺表面活性物质系统的模型，可以提供一种理解， 表面活性剂组分如何在空气/肺泡内层组织。这 信息反过来可以允许合理的设计。的治疗剂 呼吸窘迫综合症等疾病。两个具体目标，每个目标 物理和生物/生物医学部分，将在未来几年内继续进行。 资助期： (Aim 1，物理）：红外反射-吸收光谱（IRRAS）将是 开发用于有效测量构象、头基相互作用 磷脂酰基链和二级结构的倾斜角和倾斜角 水溶液中肽的有序区域（α-螺旋，β-折叠）的角度 单层原位在A/W界面。调查人员还将继续 开发数学方法，用于定量反射强度 结果的解释。 (Aim 1.一、生物学）：研究人员将探索分子水平 “挤出”假说的后果被广泛认为是 肺功能的机制。为了实现这一目标，他们将衡量 肺内特定节段的构象和方向 表面活性剂蛋白SP-B和SP-C在单层和体相环境中的作用。 最后，他们将利用IRRAS和布鲁斯特角的组合 显微镜检查以监测SP-A、-B和-C与脂质在 分子水平（IRRAS）和10 μ M规模（BAM）的单层。 (Aim 2、物理）研究人员将运用IR的新技术 显微成像，以获取光谱和空间分辨的红外图像， 异构系统（例如，神经酰胺/脂肪酸/胆固醇和其他相 分离的脂质混合物）作为第一个详细证明的效用， 这个技术。 (Aim 2、生物学）研究人员将红外成像扩展到生理学 使用角质层作为模型的系统， 皮肤屏障功能的描述假定存在大的 高度有序的非对称相的区域。他们将直接评估 域镶嵌模型的适用性，这是目前公认的模型， 角质层

DESCRIPTION (Adapted from abstract): The major focus of this laboratory to determine how the structures of lipids and proteins are altered upon their mutual interaction in a series of model and native membranes of increasing complexity, and how these structural modifications are related to function. The investigators have developed FT-IR experiments that yield quantitative information about membrane lipid conformational and orientational order and applied this technology to a physiologically relevant experimental paradigm, i.e., monolayers in situ at the air/water (A/W) interface. This experiment, a model for the pulmonary surfactant system, may provide an understanding as to how the surfactant components are organized at the air/alveolar lining. This information in turn may permit the rational design of. therapeutic agents for diseases such as respiratory distress syndrome. Two specific aims, each with a physical and biological/biomedical component, will be pursued during the coming funding period: (Aim 1, physical): IR reflection-absorption spectroscopy (IRRAS) will be developed for efficient measurement of conformations, head group interactions and tilt angles of phospholipid acyl chains and secondary structures and tilt angles of ordered regions (a-helix, Beta-sheet) of peptides in aqueous monolayers in situ at the A/W interface. The investigators will also continue to develop mathematical methods for reflected intensities for quantitative interpretation of results. (Aim 1. biological): The investigators will explore the molecular level ramifications of the "squeeze-out" hypothesis widely assumed to be the mechanism of lung function. To achieve this, they will measure the conformations and orientations of specific segments within the pulmonary surfactant proteins SP-B and SP-C in monolayer and bulk phase environments. Finally they will utilize the combination of IRRAS and Brewster Angle Microscopy to monitor interactions of SP-A, -B, and -C with lipids at the molecular level (IRRAS) and the 10 u-M scale (BAM) in monolayers. (Aim 2, physical) The investigators will apply the novel techniques of IR microscopic imaging to acquire spectrally and spatially resolved IR images from heterogeneous systems (e.g., ceramide/fatty acids/cholesterol and other phase separated lipid mixtures) as the first detailed demonstration of the utility of this technology. (Aim 2, biological) The investigators will extend IR imaging to physiological systems using stratum corneum as a model since the currently accepted molecular description of the skin barrier function postulates the existence of large domains of highly ordered lipidic phases. They will directly evaluate the applicability of domain mosaic model that is the currently accepted model of the stratum corneum.