Problems in Membrane Biophysics

9316256麦康奈尔这项研究探索了利用空气-水界面上的脂质/蛋白质单分子层来研究特定的细胞膜-单层膜相互作用。荧光显微镜是用来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。这些蛋白质被结合到脂单分子层中。利用最近发展起来的关于脂质单层物理性质的知识，通过适当标记的蛋白质/肽/脂的荧光显微镜观察，研究了MHC-肽复合体与多肽特异的、MHC限制性的T细胞杂交瘤之间的相互作用。使用细胞悬浮法仔细控制T细胞与单层的结合。检测单层中特定的MHC-肽复合体与一群T细胞的结合是一项潜在的新技术，它将导致识别反应性T细胞克隆，并最终对T细胞受体基因进行测序。地球表面大约有75%的空气-水界面。尽管这种界面具有潜在的生态和环境意义，但人们对界面上发生的物理和化学事件知之甚少。这很简单，因为在任何时候，在这个界面上出现的分子都很少。斯坦福大学哈登·麦康奈尔实验室的研究带来了在这个界面上观察化学、物理和生物事件的技术突破。这项技术涉及到只与界面结合的荧光分子探测器的应用--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上的事件。通过它们对这些荧光分子空间分布的影响，可以在空气-水界面观察到许多现象(相变、化学反应和细菌运动)。从字面上看，科学文献中已经报道了数十个使用这些技术的新观测结果。该实验室目前正在开展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. ***