LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

描述(改编自摘要)：本实验的主要重点是 确定脂类和蛋白质的结构是如何改变的 相互作用在一系列模型和天然膜的增加 复杂性，以及这些结构修改如何与功能相关。这个 研究人员开发了FT-IR实验，以产生定量的 关于膜脂构象和取向顺序的信息以及 将这项技术应用于与生理相关的实验范式， 即在空气/水(A/W)界面处原位形成单分子膜。这个实验，一个 肺表面活性物质体系的模型，可以提供对以下方面的理解 表面活性成分在空气/肺泡衬里的组织方式。这 反过来，信息可能会允许合理设计。治疗药物 呼吸窘迫综合症等疾病。两个具体目标，每个目标都有一个 物理和生物/生物医学部分，将在即将到来的 资助期： (目标1，物理)：红外反射吸收光谱(IRRAS)将 专为有效测量构象、头基相互作用而开发 磷脂酰链和二级结构的倾斜角和倾斜度 多肽在水溶液中有序区域(a-螺旋、β-折叠)的角度 在A/W界面处原位形成单分子膜。调查人员还将继续 发展定量计算反射强度的数学方法 对结果的解释。 (目标1.生物学)：研究人员将探索分子水平 “排挤”假说的后果被广泛认为是 肺功能的作用机制。为了实现这一点，他们将测量 肺内特定节段的构象和取向 单层和本体环境中的表面活性蛋白SP-B和SP-C。 最后，他们将利用IRRAS和布鲁斯特角的组合 用显微镜监测SP-A、-B和-C与脂质的相互作用 单层的分子水平(IRRAS)和10u-M尺度(BAM)。 (目标2，身体)调查人员将应用IR的新技术 用于获取光谱和空间分辨率红外图像的显微成像 多相体系(例如神经酰胺/脂肪酸/胆固醇和其他相 分离的脂质混合物)作为第一个详细演示的用途 这项技术。 (目标2，生物学)研究人员将把红外成像扩展到生理 系统使用角质层作为模型，因为目前接受的分子 对皮肤屏障功能的描述假定大的 具有高度有序的脂类相的结构域。他们将直接评估 作为当前被接受的模型的域镶嵌模型的适用性 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.