Lee Kun-Chun, Liu Andrea J
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Biophys J. 2008 Nov 15;95(10):4529-39. doi: 10.1529/biophysj.108.134783. Epub 2008 Aug 15.
We present the first numerical simulation of actin-driven propulsion by elastic filaments. Specifically, we use a Brownian dynamics formulation of the dendritic nucleation model of actin-driven propulsion. We show that the model leads to a self-assembled network that exerts forces on a disk and pushes it with an average speed. This simulation approach is the first to observe a speed that varies nonmonotonically with the concentration of branching proteins (Arp2/3), capping protein, and depolymerization rate, in accord with experimental observations. Our results suggest a new interpretation of the origin of motility. When we estimate the speed that this mechanism would produce in a system with realistic rate constants and concentrations as well as fluid flow, we obtain a value that is within an order-of-magnitude of the polymerization speed deduced from experiments.
我们展示了弹性丝驱动肌动蛋白推进的首次数值模拟。具体而言，我们使用了肌动蛋白驱动推进的树突状成核模型的布朗动力学公式。我们表明该模型会导致一个自组装网络，该网络对圆盘施加力并以平均速度推动它。这种模拟方法首次观察到速度随分支蛋白（Arp2/3）浓度、封端蛋白和解聚速率非单调变化，这与实验观察结果一致。我们的结果为运动起源提出了一种新的解释。当我们估计该机制在具有实际速率常数、浓度以及流体流动的系统中产生的速度时，我们得到的值与从实验推导的聚合速度在一个数量级范围内。
