Lai Ghee Hwee, Coridan Rob, Zribi Olena V, Golestanian Ramin, Wong Gerard C L
Department of Physics, University of Illinois at Urbana-Champaign, Urbana-Champaign, Illinois 61801, USA.
Phys Rev Lett. 2007 May 4;98(18):187802. doi: 10.1103/PhysRevLett.98.187802. Epub 2007 Apr 30.
Multivalent ions induce attractions between polyelectrolytes, but lead to finite-sized bundles rather than macroscopic phase separation. The kinetics of aggregation and bundle formation of actin is tracked using two different fluorescently labeled populations of F-actin. It is found that the growth mode of these bundles evolves with time and salt concentration, varying from an initial lateral growth to a longitudinal one at later stages. The results suggest that kinetics play a role in bundle growth, but not in the lateral size of bundles, which is constant for linear and branched topologies.
多价离子会诱导聚电解质之间产生吸引力，但会导致形成有限尺寸的束状物，而非宏观相分离。利用两种不同荧光标记的F-肌动蛋白群体来追踪肌动蛋白聚集和束状物形成的动力学过程。研究发现，这些束状物的生长模式会随时间和盐浓度而演变，从最初的横向生长转变为后期的纵向生长。结果表明，动力学在束状物生长过程中起作用，但对束状物的横向尺寸没有影响，线性和分支拓扑结构的束状物横向尺寸是恒定的。
