Scanning probe force microscopy to study biophysics of lipid rafts and their role in amyloid fibril formation

生命系统的几乎每一种功能都涉及被膜隔开的隔室之间协调和调节的物质或信号交换。质膜本身由小的动态隔室-筏组成。这些木筏是细胞交流的中心。由于它们的重要作用，人们认为越来越多的疾病与木筏有关也就不足为奇了。这些疾病包括阿尔茨海默病和帕金森病，仅举几例。因此，对脂筏性质和功能的详细研究对于理解重要生物学过程的分子机制和淀粉样蛋白相关疾病的发生具有重要意义。本项目的目的是研究由于脂筏表面电荷分布不均匀而引起的静电相互作用可能在纤维形成的起始和有效性中起重要作用。由于这些木筏的尺寸很小（纳米级），研究它们是一项艰巨的任务，需要高度先进的显微技术。我们将原子力显微镜（AFM）与周围环境中的局部表面电位测量相结合，以解决它们的结构和静电相互作用。我们将使用最近在德累斯顿技术大学开发的最先进的开尔文探针力显微镜，它允许在真空和空气中进行高分辨率的表面电位测量，并且有望在液体中应用。这项技术将适用于商用NanoWizardAFM显微镜，开尔文技术将进一步发展到在液体环境中操作。这将推进开尔文探针力显微镜技术本身，该技术目前具有低分辨率，并且仅限于在真空和空气中操作，并且将提供对脂筏在淀粉样纤维形成中的作用的深入了解。

Almost every function of a living system involves a coordinated and regulated exchange of matter or signals between compartments separated by membranes. Plasma membrane itself is composed of small dynamic compartments - rafts. These rafts are central to the communication of cells. Because of their essential role, it is not surprising that rapidly growing list of diseases is thought to be related to rafts. These include Alzheimer's and Parkinson's diseases, to list a few. Therefore detailed studies of the lipid rafts' nature and functions are important for the understanding of the molecular mechanisms of biologically important processes and initiation of amyloid related diseases. The goal of this project is to investigate the electrostatic interactions, which due to the nonuniform surface charge distribution in lipid rafts may play an important role in the initiation and effectiveness of fibril formation. Because of the rafts' small (nanometer) size, studying them is a demanding undertaking requiring highly advanced microscopic techniques. We will combine atomic force microscopy (AFM) with the local surface potential measurements in an ambient environment to address both their structure and the electrostatic interactions. We will use the most advanced modification of Kelvin probe force microscopy recently developed in Dresden Technical University, which permits high resolution surface potential measurements in vacuum and in air, and is promising for applications in liquid. This technology will be adapted to a commercial NanoWizardAFM microscope and the Kelvin technique will be further developed for operating in a liquid environment. This will advance the Kelvin probe force microscopy technique itself, which currently has low resolution and is restricted to operating in vacuum and air, as well as will provide an insight into the role of lipid rafts in amyloidal fibril formation.