Crosslinked actin networks show liquid crystal elastomer behaviour, including soft-mode elasticity
Crosslinked actin networks show liquid crystal elastomer behaviour, including soft-mode elasticity
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DOI：
10.1038/nphys567
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发表时间：
2007-05-01
期刊：
影响因子：
19.6
通讯作者：
Lubensky, Tom C.
中科院分区：
文献类型：
--
作者：
Dalhaimer, Paul;Discher, Dennis E.;Lubensky, Tom C.
具有不同长度和柔韧性的蛋白交联的肌动蛋白丝网络类似于液晶弹性体。我们模拟肌动蛋白。具有不同长度和连通性的柔性交联剂的哀叹系统，以了解一般相行为和弹性。模拟网络用的很短。悲哀和长交联剂类似于红细胞的细胞骨架，在压缩和剪切方面保持各向同性，似乎很适合血液流动。相比之下，网络长。在许多细胞类型中发现的基质显示出依赖于交联剂长度的三种向列相行为：(1)“松散”网络在零应力下各向同性，但在压缩或剪切下排列；(2)“半松散”网络在低应力下是向列的，但在扩张下变成各向同性；(3)“紧密”网络具有锁定的向列顺序，如耳朵外毛细胞的细胞骨架所示，其各向异性的遵从性指导声音传播。此外，对于具有“周期性”连接的松散网络子集。遗憾的是，发现了极其柔软的应力应变行为，正如液晶弹性体所预测的那样。
Actin filament networks with protein crosslinks of distinct length and flexibility resemble liquid crystal elastomers. We simulate actin. lament systems with flexible crosslinkers of varying length and connectivity to understand general phase behaviour and elasticity. Simulated networks with very short. laments and long crosslinkers resemble the cytoskeleton of the red blood cell and remain isotropic in compression and shear, seeming well-suited to blood flow. In contrast, networks with longer. laments as found in many cell types show three regimes of nematic phase behaviour dependent on crosslinker length: ( 1) 'loose' networks are isotropic at zero stress but align under compression or shear; ( 2) 'semi-loose' networks are nematic at low stress but become isotropic under dilation and ( 3) 'tight' networks possess a locked-in nematic order as represented by the cytoskeleton of the outer hair cell in the ear, for which anisotropic compliance directs sound propagation. Furthermore, for a subset of loose networks with 'periodic' connections among. laments, extremely soft stress - strain behaviour is found, as predicted for liquid crystal elastomers.