标题： 纤维之间的瞬时接触赋予分支肌动蛋白弹性 显示英文标题

标题： Transient contacts between filaments impart its elasticity to branched actin

摘要： 分支肌动蛋白网络在真核细胞中产生推力，并适应其环境的刚度。 它们力学和适应性的物理基础却尚未被理解。 事实上，我们在这里表明，它们的高密度和低连通性使它们超出了标准肌动蛋白弹性网络模型的范围。 我们结合高精度的机械实验、分子动力学模拟和平均场弹性理论，表明它们实际上是由压缩下纤维间接触的增殖所主导的。 这使得分支肌动蛋白与欠协调的纤维材料（如羊毛）处于同一类别中。 当网络在力的作用下生长时，纤维会像编织在一起一样相互缠绕，并在其结构中捕获接触点。 被捕获的接触点在使网络刚化方面起着类似于交联剂的作用，因此是其主动适应性力学的关键。 显示英文摘要

摘要： Branched actin networks exert pushing forces in eukaryotic cells, and adapt their stiffness to their environment. The physical basis for their mechanics and adaptability is however not understood. Indeed, here we show that their high density and low connectivity place them outside the scope of standard elastic network models for actin. We combine high-precision mechanical experiments, molecular dynamics simulations and a mean-field elastic theory to show that they are instead dominated by the proliferation of interfilament contacts under compression. This places branched actin in the same category as undercoordinated, fibrous materials such as sheep's wool. When the network is grown under force, filaments entangle as if knitted together and trap contacts in their structure. Trapped contacts play a similar role as crosslinkers in rigidifying the network, and are thus key to its active adaptive mechanics.