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arXiv 1905.03327cond-mat.stat-mechq-bio.BM
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非均相半柔性聚合物的热断裂动力学

Thermal Fracture Kinetics of Heterogeneous Semiflexible Polymers

Alexander Lorenzo, Enrique M. De La Cruz, Elena F. Koslover

摘要:

聚合物链的断裂和切断在纤维材料的失效和细胞内细丝的调节周转中起着关键作用。使用连续蠕虫状链模型,我们调查断裂的半柔性聚合物通过热弯曲波动,专注于长丝的灵活性和动力学的作用。我们的研究结果突出了一个以前不受重视的后果,在长丝中的机械不均匀性,这提高了热碎裂的速度,特别是在限制阻碍链端的运动的情况下。虽然一般适用于半柔性链与不同的弯曲刚度的区域,该模型的动机是由一个特定的生物物理系统:增强切断肌动蛋白丝之间的边界硬裸露的区域和机械软化的区域,与cofilin调节蛋白包被。这里提出的结果指出了一个潜在的机制,在一般情况下,特别是通过引入局部软化链区域,如发生与cofilin绑定的细丝网络和细胞骨架肌动蛋白网络的解体。

英文摘要:

The fracture and severing of polymer chains plays a critical role in the failure of fibrous materials and the regulated turnover of intracellular filaments. Using continuum wormlike chain models, we investigate the fracture of semiflexible polymers via thermal bending fluctuations, focusing on the role of filament flexibility and dynamics. Our results highlight a previously unappreciated consequence of mechanical heterogeneity in the filament, which enhances the rate of thermal fragmentation particularly in cases where constraints hinder the movement of the chain ends. Although generally applicable to semiflexible chains with regions of different bending stiffness, the model is motivated by a specific biophysical system: the enhanced severing of actin filaments at the boundary between stiff bare regions and mechanically softened regions that are coated with cofilin regulatory proteins. The results presented here point to a potential mechanism for disassembly of filament networks in general and cytoskeletal actin networks in particular by the introduction of locally softened chain regions, as occurs with cofilin binding.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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