Nanoscale Imaging of Membrane Surfaces

细胞表面由提供细胞结构完整性的脂膜组成，其功能是细胞与其环境之间的接口。细胞膜中脂类和蛋白质的物理组织在控制许多生物过程中起着关键作用。例如，膜被认为包含被称为木筏的小区域，这些区域含有大量的胆固醇和其他成分，在组织蛋白质和启动信号通路方面非常重要。我们开发和应用光谱和成像工具，可用于了解脂肪和蛋白质在模型膜和自然膜中是如何组织的细节，以及整体组织如何有助于控制生物功能。我们使用的工具是扫描探针显微镜和荧光光谱显微镜的组合。这些工具使人们能够绘制表面的地形图，并根据其特征荧光识别特定的成分。我们特别感兴趣的是使用高分辨率成像方法来了解膜中木筏的形成。我们的研究是在由支持的脂质双层和细胞中组成的人造膜上进行的。这项研究将有助于详细了解细胞表面发生的过程。这对于理解膜蛋白的正常和异常功能具有重要意义，膜蛋白是目前市场上超过一半的药物的靶标。这项工作还可能有助于设计生物传感器的方法，并将在化学、生物和物理之间的多学科研究项目中为学生提供培训。

The surface of cells is comprised of a lipid membrane that provides the structural integrity of the cell and functions as an interface between the cell and its environment. The physical organization of lipids and proteins in cellular membranes plays a key role in controlling many biological processes. For example, membranes are believed to contain small areas known as rafts that have large amounts of cholesterol and other components and that are important in organizing proteins and initiating signaling pathways. We develop and apply spectroscopic and imaging tools that can be used to understand the details of how lipids and proteins are organized in model and natural membranes and how the overall organization contributes to controlling biological function. The tools that we use are a combination of scanning probe microscopy and fluorescence spectroscopy and microscopy. These tools allow one to map the topography of the surface and to identify specific components based on their characteristic fluorescence. We are specifically interesting in using high resolution imaging methods to understand the formation of rafts in membranes. Our studies are carried out in artificial membranes comprised of supported lipid bilayers and in cells. This research will contribute to a detailed understanding of processes occurring at cell surfaces. This has important implications for understanding both normal and abnormal functions of membrane proteins which are the targets for over half of currently marketed drugs. The work may also contribute to approaches for designing biosensors and will provide students with training in multidisciplinary research projects at the interface between chemistry, biology and physics.