Dynamic Studies of the Adhesion, Deformation and Fusion of Monolayers, Bilayers and Membranes

该项目继续利用新型电子和原子力显微镜以及表面力测量，研究不同的双层间力和双层流动性对粘附和融合双层分子尺度变形的作用。过去的实验发现疏水力在粘附和融合中起着特别重要的作用。在这个后续项目中，各种技术被用于研究表面活性剂、脂质和结构域（横向扩散、翻转或“触发器”和交换）在非平衡相互作用（如粘附、融合和膜结构转变）中的动力学。目的是评估这些动态过程及其速率（与平衡特性相反）如何影响结构变化、粘附和融合。研究人员将尝试通过使用“笼子”钙化合物在特定的时间和地点释放二价离子，来实现类似的离子对膜相互作用的高时间和空间分辨率。互补表面力仪和电子显微镜将测量钙如何诱导膜结构变化，粘附和融合，以毫秒时间分辨率。通过原子力显微镜研究二价离子对简单Langmuir- Blodgett膜的影响，将在亚分子尺度上提供额外的结构信息。

9305868 Israelachvili This project continues the investigation of the roles of different interbilayer forces and bilayers fluidity on the molecular-scale deformations of adhering and fusing bilayers using novel electron and atomic force microscopy and surface force measurements. Past experiments identified a particularly important role for hydrophobic forces in adhesion and fusion. In this follow-up project, a variety of techniques are used to study the dynamics of surfactants, lipids and domains (lateral diffusion, overturning or 'flip-flop', and exchange) during nonequilibrium interactions such as adhesion, fusion and membrane structural transitions. The aim is to asess how these dynamic processes and their rates - in contrast to equilibrium properties - affect structural changes, adhesion and fusion. The investigators will attempt to achieve similarly high time and spatial resolution of ionic effects on membrane interactions by using 'cages' calcium compounds to liberate divalent ions at a specific time and place. Complementary surface force apparatus and cyro-electron microscopy measurements will be made how calcium induces membrance structural changes, adhesion and fusion with millisecond time resolution. Additional structural information will be provided at the sub-molecular scale by studying the effects of divalent ions on simple Langmuir- Blodgett membranes using the atomic force microscope.