Problems in Membrane Biophysics

9316256 McConnell这项研究探讨了在空气-水界面使用脂质/蛋白质单层来研究特定的细胞膜-单层膜相互作用。 荧光显微镜是用于进行这些研究的主要技术。 特别感兴趣的膜蛋白是主要组织相容性复合体（MHC）的II类分子。 这些蛋白质被掺入脂质单层中。 MHC-肽复合物和肽特异性，MHC限制性T-细胞杂交瘤之间的相互作用进行了研究，适当标记的蛋白质/肽/脂质的荧光显微镜观察，利用最近开发的知识有关的脂质单层的物理性质。 使用细胞悬浮法仔细控制T细胞在单层上的贴壁。 检测单层中特异性MHC-肽复合物与T细胞群体的结合是一种潜在的新技术，其导致反应性T细胞克隆的鉴定，以及T细胞受体基因的最终测序。 %地球表面大约有75%是空气-水界面。 尽管该界面具有潜在的生态和环境意义，但对界面的物理和化学事件知之甚少。 这仅仅是因为在任何一个时间，在这个界面上存在的分子都很少。 斯坦福大学的哈登·麦康奈尔实验室的研究在观察这个界面上的化学、物理和生物事件的技术上取得了突破。 这项技术涉及到荧光分子探针的应用，这些探针只与界面结合-它们不溶于水，也不会蒸发到空气中。 这些探针允许使用简单的荧光光学显微镜观察界面处的事件。 许多现象（相变，化学反应，细菌运动）可以观察到在空气-水界面上的这些荧光分子的空间分布的影响。 科学文献中使用这些技术报道了数十种新的观察结果。 该实验室目前正在进行的一项研究涉及电场对生物细胞的影响。 ***

9316256 McConnell This research explores the use of lipid/protein monolayers at the air-water interface to study specific cell membrane-monolayer membrane interactions. Fluorescence microscopy is the principle technique used to carry out these studies. Membrane proteins of special interest are the class II molecules of the major histocompatibility complex (MHC). These proteins are incorporated in lipid monolayers. The interaction between MHC- peptide complexes and peptide specific, MHC restricted T-cell hybridomas is studied by fluorescence microscopic observations of suitably labeled protein/peptide/lipid, taking advantage of recently developed knowledge concerning physical properties of lipid monolayers. Apposition of T-cells to the monolayers is carefully controlled using cell suspension methods. Detection of the binding of specific MHC-peptide complexes in monolayers to a population of T-cells is a potential novel technique leading to the identification of reactive T-cells clones, and to the eventual sequencing of T-cell receptor genes. %%% The surface of the earth is approximately 75% air-water interface. In spite of the potential ecological and environmental significance of this interface, remarkably little is known about physical and chemical events that are interfacial. This is simply because so few molecules are present at this interface at any one time. Research in the laboratory of Harden McConnell at Stanford has brought about a breakthrough in technique for observing chemical, physical and biological events at this interface. This technique has involved the application of fluorescent molecular probes that bind only to the interface--they are not soluble in water, nor do they vaporize into the air. These probes permit the observation of events at the interface using a simple fluorescence optical microscope. Many phenomena (phase transitions, chemical reactions, and bacterial motion) can be observed at the air-water interface by their eff ects on the spatial distribution of these fluorescent molecules. Literally dozens of new observations have been reported in the scientific literature using these techniques. A study currently being initiated in this laboratory concerns the effects of electrical fields on biological cells. ***