Department of Civil and Environmental Engineering, North Dakota State University, Fargo, North Dakota 58105, United States.
Biomacromolecules. 2021 Feb 8;22(2):907-917. doi: 10.1021/acs.biomac.0c01602. Epub 2021 Jan 22.
Actin molecules are essential structural components of the cellular cytoskeleton. Here, we report a comprehensive analysis of F-actin's deformation behavior and highlight underlying mechanisms using steered molecular dynamics simulations (SMD). The investigation of F-actin was done under tension, compression, bending, and torsion. We report that the dissociation pattern of conformational locks at intrastrand and interstrand G-actin interfaces regulates the deformation response of F-actin. The conformational locks at the G-actin interfaces are portrayed by a spheroidal joint, interlocking serrated plates' analogy. Further, the SMD simulation approach was utilized to evaluate Young's modulus, flexural rigidity, persistent length, and torsional rigidity of F-actin, and the values obtained were found to be consistent with available experimental data. The evaluation of the mechanical properties of actin and the insight into the fundamental mechanisms contributing to its resilience described here are necessary for developing accurate models of eukaryotic cells and for assessing cellular viability and mobility.
肌动蛋白分子是细胞细胞骨架的基本结构组成部分。在这里，我们使用定向分子动力学模拟（SMD）报告了对 F-肌动蛋白变形行为的全面分析，并强调了潜在的机制。在张力、压缩、弯曲和扭转下对 F-肌动蛋白进行了研究。我们报告说，在 F-肌动蛋白中，链内和链间 G-肌动蛋白界面构象锁的解离模式调节 F-肌动蛋白的变形响应。G-肌动蛋白界面处的构象锁通过一个球状关节来描绘，类似于互锁的锯齿状板。此外，还使用 SMD 模拟方法评估了 F-肌动蛋白的杨氏模量、弯曲刚度、持久长度和扭转刚度，并且发现所获得的值与现有实验数据一致。这里描述的肌动蛋白力学性能的评估以及对有助于其弹性的基本机制的深入了解，对于开发真核细胞的精确模型以及评估细胞活力和迁移能力是必要的。
