Cytoskeletal Deformation at High Strains and the Role of Cross-link Unfolding or Unbinding
Cytoskeletal Deformation at High Strains and the Role of Cross-link Unfolding or Unbinding
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DOI：
10.1007/s12195-009-0048-8
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发表时间：
2009-03-01
影响因子：
2.8
通讯作者：
Kamm, Roger D.
中科院分区：
文献类型：
--
作者：
Lee, Hyungsuk;Pelz, Benjamin;Kamm, Roger D.
肌动蛋白细胞骨架因其生物学意义和独特的流变性，长期以来一直是人们关注的焦点。虽然F-肌动蛋白网络已经得到了广泛的实验研究，并提出了几个理论模型，但肌动蛋白结合蛋白(ABPs)和肌动蛋白之间的详细分子相互作用。监管网络行为的遗憾仍不清楚。在这里，使用一种体外测试，允许直接测量一个肌动蛋白交联蛋白和两个肌动蛋白之间的键。悲叹，我们演示了力诱导的解绑和展开。拉明。解离的临界力为70+/-23pN，去折叠的临界力为57+/-19pN，表明这两种临界力都是控制细胞骨架流变学的重要机制。我们还获得了交联型F-肌动蛋白网络对光学捕获微珠的机械响应，并观察到意味着交联链断裂或展开的突变。通过对实验进行计算机模拟来解释这些测量结果，以便更深入地了解物理机制。
Actin cytoskeleton has long been a focus of attention due to its biological significance and unique rheological properties. Although F-actin networks have been extensively studied experimentally and several theoretical models proposed, the detailed molecular interactions between actin binding proteins (ABPs) and actin. laments that regulate network behavior remain unclear. Here, using an in vitro assay that allows direct measurements on the bond between one actin cross-linking protein and two actin. laments, we demonstrate force-induced unbinding and unfolding of. lamin. The critical forces prove to be similar, 70 +/- 23 pN for unbinding and 57 +/- 19 pN for unfolding, suggesting that both are important mechanisms governing cytoskeletal rheology. We also obtain the mechanical response of a cross-linked F-actin network to an optically trapped microbead and observe abrupt transitions implying rupture or unfolding of cross-links. These measurements are interpreted with the aid of a computational simulation of the experiment to provide greater insight into physical mechanisms.