Nanoscale structure of lipid membrane and its role in membrane-mediated interactions

细胞膜是生命的基本单位，由纳米级、高动态筏组成，由浓缩脂质、胆固醇和膜蛋白组成。这些木筏是细胞组织的一个主要方面，是细胞与周围环境交流的中心。真正的生物膜是非常复杂的，因此在生物物理研究中广泛使用合成脂质双层或模型脂质膜来模拟它们。******我研究计划的主要目标有两个方面：1)发现模型脂膜生物物理学中的新现象，设计复杂的和生物学相关的模型膜，阐明膜与带电肽相互作用的分子机制。这将为了解阿尔茨海默病（AD）中淀粉样蛋白毒性的分子机制和抗菌作用机制提供基础平台；2)将脂质膜与纳米等离子体底物相结合，开发新型膜基生物传感平台。******研究模拟神经元膜的模型膜的纳米级结构对于了解淀粉样蛋白与膜结合的分子机制和淀粉样蛋白在AD中的毒性具有重要意义。我建议研究淀粉样蛋白和抗菌肽之间的异同，以揭示它们与脂质膜相互作用的基本分子机制。我的小组将阐明脂质组成和胆固醇诱导结构域形成和改变脂质膜静电非均质性的影响。为了解决这些问题，我们将结合原子力显微镜（AFM）、原子力光谱（AFS）、调频开尔文探针力显微镜（FM-KPFM）、黑脂膜（BLM）和等离子体学方法，包括表面等离子体共振（SPR）和表面增强拉曼光谱（SERS）。这些先进的物理方法将用于验证我的假设，即膜纳米级结构是一种动态特性，在其与带电肽的相互作用中起着积极和决定性的作用。我们将开发将模型脂质膜附着在金属纳米结构底物上的方案，并使用SPR和SERS方法定量和高灵敏度地实时监测肽-脂质相互作用。这将为生物传感应用开辟新的方向，允许监测膜蛋白在各种应用中的相互作用。******提出的研究计划将推进膜生物物理学领域的知识，将进一步深入了解纳米级膜结构在淀粉样蛋白和抗菌肽作用中的作用，并将为开发用于蛋白质检测的新型生物传感器提供平台。此外，我的研究项目将为多个不同层次的学员提供一个优秀的跨学科培训机会。***********

Cellular membrane is a fundamental unit of life and consists of nanoscopic, highly dynamic rafts composed of condensed lipids, cholesterol, and membrane proteins. These rafts are a major aspect of cell organization and central to the communication of cells with their environs. Real biological membranes are very complex and synthetic lipid bilayers or model lipid membranes are therefore widely used to mimic them in biophysical studies. ******The main goals of my research program are two-fold: 1) to discover novel phenomena in the biophysics of model lipid membranes, design complex and biologically relevant model membranes and elucidate the molecular mechanism of membrane interactions with charged peptides. This will provide a fundamental platform for understanding the molecular mechanism of amyloid toxicity in Alzheimer's disease (AD) and the mechanism of antimicrobial action; and 2) to develop novel membrane-based biosensing platforms, by merging lipid membrane with nanofabricated plasmonic substrates. ******Studying the nanoscale structure of model membranes, which mimic neuronal membranes are important for the understanding of the molecular mechanisms of amyloid binding to the membrane and amyloid toxicity in AD. I propose to investigate the similarities and differences between amyloid and antimicrobial peptides in order to expose the fundamental molecular mechanisms of their interactions with lipid membranes. My group will elucidate the effects of lipid composition and cholesterol that induce domain formation and change electrostatic heterogeneity in the lipid membrane. To tackle these problems, we will combine atomic force microscopy (AFM), atomic force spectroscopy (AFS), frequency modulation Kelvin probe force microscopy (FM-KPFM), Black Lipid Membrane (BLM) and plasmonics methods, including surface Plasmon resonance (SPR) and surface enhanced Raman spectroscopy (SERS). These advanced physical methods will be used to test my hypothesis that the membrane nanoscale structure is a dynamic property which plays an active and decisive role in its interactions with charged peptides. We will develop protocols to attach model lipid membrane to metallic nanostructured substrates and use SPR and SERS methods to monitor real time peptide-lipid interactions quantitatively and with high sensitivity. This will open new directions in biosensing applications allowing for monitoring membrane proteins interactions for various applications.******The proposed research program will advance knowledge in the areas of membrane biophysics, will provide further insight into the role of nanoscale membrane structure in amyloidal and antimicrobial peptides action and will serve as platform for the development of novel biosensors for protein detection. Furthermore, my research program will provide an excellent interdisciplinary training opportunity for multiple trainees of all levels.***********