Lipid Control of Membrane Protein Organization

描述（由申请人提供）：本实验室的长期目标是确定脂质/蛋白质相互作用在肺表面活性物质功能中的作用。最近的兴趣是确定各种脂质物质在皮肤渗透性屏障结构中的作用。将追求两个具体目标，每个目标都有与这些目标有关的物理和生物/生物医学组成部分： 目标1：身体状况：扩展红外反射-吸收光谱法（IRRAS），用于测定A/W界面处脂质单分子层的三维结构元素。 生物学：为了检验疏水表面活性蛋白SP-B和C促进多层膜形成/稳定的假设，该多层膜在肺压缩-扩张循环期间充当表面活性物质的储库。为了补充IRRAS，布鲁斯特角显微镜，压力-面积等温线，和脉动气泡表面测量将用于表征这些薄膜。合成肽的等效实验将有助于确定肽作为呼吸窘迫综合征等疾病的有用治疗剂所需的结构特征。我们还将评估肺表面活性物质SP-A类似物与脂质和其他配体的相互作用，以确定其在管状髓鞘形成和宿主防御中的作用。 目标二：身体状况：应用3种新型的振动显微成像技术（红外显微成像、共聚焦拉曼显微成像和衰减全反射成像），在1.5 mm至4 mm的距离范围内获得空间分辨的分子结构信息。这些将用于研究皮肤屏障模型系统中脂质结构域的形成。该实验旨在了解各种神经酰胺物质在屏障功能中的作用。 生物学：利用这些方法研究皮肤中分子组分的三维空间分布，以及渗透促进剂和药物载体的渗透途径。最后，振动光谱对分子结构的敏感性将用于绘制渗透促进剂对脂质构象和蛋白质二级结构的影响。

DESCRIPTION (provided by applicant): A long-term goal of this laboratory has been to determine the role of lipid/protein interaction in the function of pulmonary surfactant. A more recent interest has been to determine the roles of the various lipid species in the structure of the barrier to permeability in skin. Two specific aims, each with a physical and biological/biomedical component related to these goals, will be pursued: Aim 1: Physical: To extend infrared reflection-absorption spectroscopy (IRRAS), for determination of elements of the 3-dimensional structure of lipid monolayers in situ at the A/W interface. Biological: To test the hypothesis that the hydrophobic surfactant proteins SP-B and C facilitate the formation/stabilization of multilayers that act as reservoirs for surface-active material during lung compression-expansion cycles. To complement IRRAS, Brewster angle microscopy, pressure-area isotherms, and pulsating bubble surfactometry will be used to characterize these films. Equivalent experiments with synthetic peptides will help define structural characteristics needed for peptides to be useful therapeutic agents for diseases such as respiratory distress syndrome. We will also evaluate the interactions of lung surfactant SP-A analogues with lipids and other ligands to determine its role in tubular myelin formation and in host defense. Aim 2: Physical: To apply 3 novel vibrational microscopic imaging technologies (IR microscopic imaging, confocal Raman microscopy, and attenuated total reflectance imaging) to acquire spatially resolved molecular structure information at distance scales from 1.5 mm to 4 mm. These will be used to study lipid domain formation in model systems for the skin barrier. The experiment aims to understand the role of the various ceramide species in barrier function. Biological: To use these methods to study the 3-D spatial distribution of the molecular constituents of skin as well as the permeation pathways of penetration enhancers and drug delivery vehicles. Finally, the sensitivity of vibrational spectra to molecular structure will be used to map the effects of penetration enhancers on lipid conformation and protein secondary structure.