Aprodu Iuliana, Soncini Monica, Montevecchi Franco Maria, Redaelli Alberto
Department of Bioengineering, Politecnico di Milano, Milano, Italy.
J Appl Biomater Biomech. 2010 Jan-Apr;8(1):20-7.
Knowledge of the mechanical behavior of myosin and actin monomer is critical for understanding the molecular mechanism of actomyosin-based muscle and non-muscle motility. Different experimental studies concerning actomyosin interaction have been performed in vitro, but studies at the single molecule level have just begun. The aim of this study was to provide a mechanical characterization of myosin II and actin monomer using a numerical approach.
The elastic properties of the two proteins involved in muscle contraction were assessed by performing stretching simulations up to 10% protein elongation using the restraining method. Interaction properties of the actomyosin complex were evaluated at eight intermolecular distances during which the entire system was left free to move.
According to our results, the values of the elastic modulus of the myosin motor domain and actin are 0.30 GPa, and 0.08 GPa, respectively. As for the actomyosin complex, the interaction force has a maximum value of 541.15 pN.
Mechanical properties of molecular motors are currently being debated. Our results match a number of experimental data, therefore, supporting the idea that molecular mechanics may be a powerful tool to find a way in this complex subject.
了解肌球蛋白和肌动蛋白单体的力学行为对于理解基于肌动球蛋白的肌肉和非肌肉运动的分子机制至关重要。关于肌动球蛋白相互作用的不同实验研究已在体外进行，但单分子水平的研究才刚刚开始。本研究的目的是使用数值方法对肌球蛋白II和肌动蛋白单体进行力学表征。
通过使用约束方法进行拉伸模拟直至蛋白质伸长10%，评估参与肌肉收缩的两种蛋白质的弹性特性。在八个分子间距离处评估肌动球蛋白复合物的相互作用特性，在此期间整个系统可自由移动。
根据我们的结果，肌球蛋白运动结构域和肌动蛋白的弹性模量值分别为0.30 GPa和0.08 GPa。至于肌动球蛋白复合物，相互作用力的最大值为541.15 pN。
分子马达的力学性质目前存在争议。我们的结果与许多实验数据相符，因此支持分子力学可能是在这个复杂主题中找到方法的有力工具这一观点。
