Coupling mechanism of multi-force interactions in the myosin molecular motor

• Published in: Chinese science bulletin Vol. 55; no. 31; pp. 3538 - 3544
• Main Authors: Guo, Zhao, Yin, YueHong
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science China Press 01.11.2010
• Subjects: Casimir力; Chemistry/Food Science; Earth Sciences; Engineering; Humanities and Social Sciences; Life Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); 分子动力学模拟; 分子马达; 相互作用; 耦合机制; 肌动蛋白; 肌球蛋白; 范德华力; actin filaments; van der Waals force; Casimir force; molecular motor; Monte Carlo simulation; myosin II
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-010-4120-5

The dynamics of the myosin molecular motor as it binds to actin filaments during muscle contraction are still not clearly understood. In this paper, we focus on the coupling mechanism of multi-force interactions in the myosin molecule during its interaction with actin. These forces include the electrostatic force, the van der Waals force and the Casimir force in molecular dynamic simulations of the molecules in solvent with thermal fluctuations, Based on the Hamaker approach, van der Waals and Casimir potentials and forces are calculated between myosin and actin. We have developed a Monte Carlo method to simulate the dynamic activity of the molecular motor. We have shown that because of the retardation effect, the van der Waals force falls into the Casimir force when the distance between the surfaces is larger than 3 nm. When the distance is smaller than 3 nm, the electrostatic force and the van der Waals force increase until the myosin becomes attached to the actin. Over the distances studied in the present work, the electrostatic force dominates the attractive interactions. Our calculations are in good agreement with recently reported experimental results.