Department of Physics, Washington University, One Brookings Drive, Campus Box 1105, St Louis, MO 63130, USA.
Phys Biol. 2013 Jun;10(3):036006. doi: 10.1088/1478-3975/10/3/036006. Epub 2013 Apr 17.
Forces and stresses generated by the action of myosin minifilaments are analyzed in idealized computer-generated actin bundles, and compared to results for isotropic actin networks. The bundles are generated as random collections of actin filaments in two dimensions with constrained orientations, crosslinked and attached to two fixed walls. Myosin minifilaments are placed on actin filament pairs and allowed to move and deform the network so that it exerts forces on the walls. The vast majority of simulation runs end with contractile minifilament stress, because minifilaments rotate into energetically stable contractile configurations. This process is aided by the bending and stretching of actin filaments, which accomodate minifilament rotation. Stresses for bundles are greater than those for isotropic networks, and antiparallel filaments generate more tension than parallel filaments. The forces transmitted by the actin network to the walls of the simulation cell often exceed the tension in the minifilament itself.
在理想化的计算机生成的肌动蛋白束中分析了肌球蛋白微丝作用产生的力和应力，并将其与各向同性肌动蛋白网络的结果进行了比较。束是在二维空间中作为肌动蛋白丝的随机集合生成的，其方向受到约束，交联并附着在两个固定壁上。将肌球蛋白微丝放置在肌动蛋白丝对上，并允许其移动和变形网络，从而使其对壁施加力。由于微丝旋转到能量稳定的收缩构型，因此大多数模拟运行最终都会产生收缩微丝的应力。该过程得益于肌动蛋白丝的弯曲和拉伸，这使微丝的旋转成为可能。束的应力大于各向同性网络的应力，并且与平行丝相比，反平行丝产生更大的张力。肌动蛋白网络传递到模拟细胞壁的力通常超过微丝本身的张力。
