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处于热力学平衡状态，因为它们不是处于静止状态，而是连续和不连续地受到进出系统的物质和能量流动的影响。几乎所有发生在活细胞中的动态过程都以三磷酸腺苷的形式消耗能量。通常被认为是“活跃的”过程，它们明显失衡，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、胞吐和内吞、钙振荡、尖峰和波动等。在分子水平上，ATP的消耗过程包括肌动蛋白细丝和微管的聚合、分子马达驱动的细胞骨架细丝的运输、泵跨膜的离子运输、蛋白质合成和T细胞受体信号转导的动力学校对等。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。活跃的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上(例如，在发育过程中)以及微观水平上(例如，肌动蛋白聚合、细菌细胞壁上黏附斑块的分布或细胞内和细胞内的钙波)都是丰富的。显然，水的不同相不能仅从单个水分子的性质中读出，很明显，单凭单个肌动蛋白单体、分子马达和核子不能理解细胞迁移过程中形成拉梅尔-脂膜的动力学现象。要了解细胞和亚细胞功能的出现，需要的不仅仅是单一的分子信息(鉴定、序列和结构)，而对这些合作的动态非平衡现象的识别、定量分析和理论建模，是本次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.