SFB 1027: Physical Modelling of Non-Equilibrium Processes in Biological Systems

“非平衡”是物理学中的一个概念，表示物质脱离热力学平衡的一种状态。自然界中发现的大多数系统都不是处于热力学平衡状态，因为它们不是处于固定状态，而是连续或间断地受到物质和能量流入和流出系统的影响。几乎所有发生在活细胞中的动态过程都以ATP的形式消耗能量。通常被称为“活跃”过程，它们明显不平衡，包括细胞骨架重组、细胞内运输、细胞迁移和极化、跨膜离子运输、胞外作用和胞内作用、钙振荡、峰状和波状等。在分子水平上，ATP消耗过程包括肌动蛋白细丝和微管的聚合，沿着细胞骨架细丝的分子马达驱动运输，离子通过泵跨膜运输，蛋白质合成和T细胞受体信号转导的动力学校对等等。最后，在更大的尺度上，蛋白质和细菌膜的聚集和时间演化以及组织的形成和重塑。主动动力学过程涉及许多粒子的合作，这就是为什么理解参与成分相互作用中出现的集体效应是重要的。在生物系统中，模式形成的概念在宏观（例如在发育过程中）和微观水平（例如肌动蛋白聚合，细菌细胞壁上粘附斑块的分布或细胞间和细胞内钙波）上都很丰富。很明显，水的不同相不能仅仅从单个水分子的性质中读出，很明显，在细胞迁移过程中，像脂质层形成这样的动力学现象不能仅仅基于单个肌动蛋白单体、分子马达和成核体来理解。要理解细胞和亚细胞功能的出现，我们需要的不仅仅是单个分子的信息（鉴定、序列和结构），而这些合作动态非平衡现象的鉴定、定量分析和理论建模是本CRC的中心焦点。

Non-equilibrium” is a concept from physics and denotes a state of matter out of thermodynamic equilibrium. Most systems found in nature are not in thermodynamic equilibrium because they are not in stationary states and are continuously and discontinuously subject to flux of matter and energy to and from the systems. Nearly all dynamical processes occurring in living cells consume energy in the form of ATP. Commonly de-noted as “active” processes they are manifestly out-of-equilibrium and include cytoskeleton reorganization, intracellular transport, cell migration and polarization, ion transport across membranes, exocytosis and en-docytosis, calcium oscillations, spikes and waves, and more. On the molecular level ATP consuming pro-cesses include polymerization of actin filaments and microtubules, molecular motor driven transport along cytoskeletal filaments, ion transport across membranes with pumps, kinetic proofreading in protein synthe-sis and T cell receptor signal transduction, and many more. Finally, on a larger scale the aggregation and temporal evolution of protein and bacterial films and tissue formation and remodeling. Active dynamical processes involve the cooperation of many particles, which is why the understanding of collective effects emerging in the interplay of the participating constituents is important. In biological systems the concept of pattern formation is abundant on macroscopic (e.g. during development) as well as on microscopic levels (e.g. actin polymerization, the distribution of adhesive patches on the bacterial cell wall or inter- and intra-cellular calcium waves). As it is obvious that the different phases of water cannot be read off from the properties of a single water molecule alone, it is clear that dynamical phenomena like the formation of lamel-lipodia during cell migration cannot be understood on the basis of individual actin-monomers, molecular motors and nucleators alone. One needs more than the single molecular information (identification, se-quence and structure) to understand the emergence of cellular and subcellular functions, and the identifica-tion, quantitative analysis and theoretical modeling of these cooperative dynamical non-equilibrium phe-nomena, are the central foci of this CRC.