Unfolding cross-linkers as rheology regulators in F-actin networks
Unfolding cross-linkers as rheology regulators in F-actin networks
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DOI：
10.1103/physreve.75.041909
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发表时间：
2007-04-01
影响因子：
2.4
通讯作者：
Levine, Alex J.
中科院分区：
文献类型：
--
作者：
DiDonna, B. A.;Levine, Alex J.
我们报告的非线性力学性能的统计均匀，各向同性的半柔性网络交联的聚合物含有许多小的展开域，如无处不在的F-肌动蛋白交联剂细丝。我们发现，包含这样的蛋白质有一个巨大的影响网络的大应变行为。超过应变阈值，这取决于网络密度，蛋白质结构域的展开导致体剪切软化。超过这个临界应变，网络自发地组织起来，使得细丝蛋白交联剂的可观部分处于结构域展开的阈值。我们讨论通过一个简单的平均场模型的原因，这个网络组织，并建议它可能是在体外和细胞内微观流变学实验中观察到的幂律松弛的来源。我们提出的数据，充分证明我们的模型简化的网络架构。
We report on the nonlinear mechanical properties of a statistically homogeneous, isotropic semiflexible network cross-linked by polymers containing numerous small unfolding domains, such as the ubiquitous F-actin cross-linker filamin. We show that the inclusion of such proteins has a dramatic effect on the large strain behavior of the network. Beyond a strain threshold, which depends on network density, the unfolding of protein domains leads to bulk shear softening. Past this critical strain, the network spontaneously organizes itself so that an appreciable fraction of the filamin cross-linkers are at the threshold of domain unfolding. We discuss via a simple mean-field model the cause of this network organization and suggest that it may be the source of power-law relaxation observed in in vitro and in intracellular microrheology experiments. We present data which fully justify our model for a simplified network architecture.