Single Particle and Polymer Tracking in Two-Dimensional Energy Landscapes

二维能量景观中的单粒子和聚合物追踪

• 批准号: 58201181
• 负责人: Professor Dr. Josef Alfons Käs
• 金额: --
• 依托单位: Abteilung Physik der weichen Materie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/58201181?language=en
• 关键词: Single; Particle; Polymer; Tracking; Two

Membranes of biological cells exemplify a complex film for diffusive transport of proteins and lipids (i.e. nano-sized objects) and can teach us how to control diffusive two-dimensional transport from the nano- to micro-scale. In inhomogeneous lipid membranes a wide variety of interactions from simple steric repulsion to complex viscous or electrostatic interactions can locally influence the motion of a probe particle. Here, we focus on the impact of the interplay between steric repulsion of rigid domains and attractive dipole-dipole/charge interactions on local diffusion. Our previous results indicate that changes in the domain structure in Langmuir monolayers, supported bilayers, and giant vesicles can switch between one- and two-dimensional diffusion as well as Brownian and subdiffusion. First, we will track the motions of point-like probes (latex spheres, quantum dots, quantum dots coupled to lipids) in changing energy landscapes modulated by domain-size and shape. We will not only learn how to switch in a controlled fashion between one- and two dimensional as well as Brownian and subdiffusive transport, but we will also catalogue the complex energy landscapes in these complex films. Secondly, we analyze the diffusive behavior of polymers in such an energy landscape. Polymers as connected chain of point diffusors (DNA, actin filaments) have internal degrees of freedom. Their behavior can be better understood knowing first what a single point diffusor does. For many biological processes nature prefers two-dimensional diffusive over directed molecular motorbased transport. Understanding how diffusion in membranes can be modulated will help to comprehend why evolution has frequendy chosen this route.

生物细胞膜是一种复杂的膜，用于蛋白质和脂质（即纳米尺寸的物体）的扩散运输，并可以教我们如何控制从纳米到微米尺度的扩散二维运输。在不均匀的脂质膜中，从简单的空间排斥到复杂的粘性或静电相互作用的各种相互作用可以局部地影响探针粒子的运动。在这里，我们专注于刚性域的空间排斥和有吸引力的偶极-偶极/电荷相互作用对局部扩散的影响。我们以前的研究结果表明，在朗缪尔单分子膜，支持双层，和巨大的囊泡的域结构的变化可以切换之间的一维和二维扩散以及布朗和亚扩散。首先，我们将跟踪点样探针（乳胶球，量子点，量子点耦合到脂质）在不断变化的能量景观调制域的大小和形状的运动。我们不仅将学习如何在一维和二维以及布朗和亚扩散传输之间以可控的方式切换，而且我们还将在这些复杂的电影中对复杂的能量景观进行编目。其次，我们分析了聚合物在这样一个能源景观的扩散行为。聚合物作为点扩散体（DNA、肌动蛋白丝）的连接链具有内部自由度。首先了解单点扩散器的作用，可以更好地理解它们的行为。对于许多生物过程，自然界更喜欢二维扩散而不是定向分子马达运输。了解细胞膜中的扩散是如何被调节的，将有助于理解为什么进化经常选择这条路线。