Kierfeld Jan, Kühne Torsten, Lipowsky Reinhard
Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14424 Potsdam, Germany.
Phys Rev Lett. 2005 Jul 15;95(3):038102. doi: 10.1103/PhysRevLett.95.038102. Epub 2005 Jul 14.
Bundles of semiflexible polymers such as actin filaments are studied theoretically. The bundle formation is governed by attractive filament interactions mediated by cross-linking sticker molecules. Using a combination of analytical arguments and Monte Carlo simulations, it is shown that the formation of bundles of parallel filaments requires a threshold concentration of linkers which becomes independent of the filament number for large bundles. The unbinding of bundles happens in a single, discontinuous transition. We discuss the behavior of the bundle thickness at and below the transition. In the bound phase, large bundles tend to segregate into sub-bundles due to slow kinetics. Our results are in qualitative agreement with experiments on F-actin in the presence of the cross-linking protein alpha-actinin.
对诸如肌动蛋白丝等半柔性聚合物束进行了理论研究。束的形成由交联贴纸分子介导的丝状吸引力相互作用控制。通过结合解析论证和蒙特卡罗模拟表明，平行丝束的形成需要连接子的阈值浓度，对于大束而言，该浓度变得与丝的数量无关。束的解聚发生在单一的、不连续的转变中。我们讨论了转变时及转变以下束厚度的行为。在结合相中，由于动力学缓慢，大束倾向于分离成子束。我们的结果与存在交联蛋白α-肌动蛋白时F-肌动蛋白的实验定性一致。
