Detailed Balance Broken by Catch Bond Kinetics Enables Mechanical‐Adaptation in Active Materials
Detailed Balance Broken by Catch Bond Kinetics Enables Mechanical‐Adaptation in Active Materials
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DOI：
10.1002/adfm.202006745
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发表时间：
2020-12
影响因子：
19
通讯作者：
A. Tabatabai;Daniel S. Seara;Joseph Tibbs;V. Yadav;Ian Linsmeier;M. Murrell
中科院分区：
文献类型：
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作者：
A. Tabatabai;Daniel S. Seara;Joseph Tibbs;V. Yadav;Ian Linsmeier;M. Murrell
与几乎所有工程材料不同，生物材料含有在负载下减弱的键，生物材料含有在负载下增强的“捕获”键。因此，材料，如细胞骨架，可以调整其机械性能，以响应其内部的非平衡（主动）应力状态。然而，大尺度材料性质如何随着平衡距离的变化而变化是未知的，以及主动应力和结合动力学在建立这个距离中的相对作用。通过粗粒化的分子动力学模拟，探索了捕获键打破详细平衡对肌动球蛋白细胞骨架模型内能量积累和耗散的影响。研究发现，细节平衡被打破的程度唯一地决定了具有特征时间反演对称性的大尺度流固相变。过渡关键取决于捕捉债券的强度，这表明主动应力是必要的，但不足以安装一个自适应的机械响应。
Unlike nearly all engineered materials which contain bonds that weaken under load, biological materials contain “catch” bonds which are reinforced under load. Consequently, materials, such as the cell cytoskeleton, can adapt their mechanical properties in response to their state of internal, non‐equilibrium (active) stress. However, how large‐scale material properties vary with the distance from equilibrium is unknown, as are the relative roles of active stress and binding kinetics in establishing this distance. Through course‐grained molecular dynamics simulations, the effect of breaking of detailed balance by catch bonds on the accumulation and dissipation of energy within a model of the actomyosin cytoskeleton is explored. It is found that the extent to which detailed balance is broken uniquely determines a large‐scale fluid‐solid transition with characteristic time‐reversal symmetries. The transition depends critically on the strength of the catch bond, suggesting that active stress is necessary but insufficient to mount an adaptive mechanical response.