Effect of tensile force on the mechanical behavior of actin filaments

JOURNAL OF BIOMECHANICS

卷:44

Article

Matsushita, Shinji^1,2,3  Inoue, Yasuhiro^1,2,3  Hojo, Masaki⁴  Sokabe, Masahiro^5,6  Adachi, Taiji^1,2,3 

[1] Kyoto Univ, Inst Frontier Med Sci, Res Ctr Nano Med Engn, Dept Biomech,Sakyo Ku, Kyoto 6068507, Japan

[2] Kyoto Univ, Grad Sch Engn, Dept Micro Engn, Sakyo Ku, Kyoto 6068501, Japan

[3] RIKEN Hirosawa, VCAD Syst Res Program, Computat Cell Biomech Team, Wako, Saitama 3510198, Japan

[4] Kyoto Univ, Grad Sch Engn, Dept Mech Engn & Sci, Sakyo Ku, Kyoto 6068501, Japan

[5] Nagoya Univ, Grad Sch Med, Dept Physiol, Nagoya, Aichi 4668550, Japan

[6] Nagoya Univ, Res Ctr Innovat Nanobiodevice 1, Nagoya, Aichi 4648603, Japan

关键词: Actin filament;    Tensile force;    Mechanical properties;    Mechano-chemical interactions;    Steered molecular dynamics simulation;    Computational biomechanics;    Cell mechanics;   

DOI  :  10.1016/j.jbiomech.2011.04.012

来源: Elsevier

【 摘 要 】

Actin filaments are the most abundant components of the cellular cytoskeleton, and play critical roles in various cellular functions such as migration, division and shape control. In these activities, mechanical tension causes structural changes in the double-helical structure of the actin filament, which is a key modulator of cytoskeletal reorganization. This study performed large-scale molecular dynamics (MD) and steered MD simulations to quantitatively analyze the effects of tensile force on the mechanical behavior of actin filaments. The results revealed that when a tensile force of 200 pN was applied to a filament consisting of 14 actin subunits, the twist angle of the filament decreased by approximately 20 degrees, corresponding to a rotation of approximately -2 degrees per subunit, representing a critical structural change in actin filaments. Based on these structural changes, the variance in filament length and twist angle was found to decrease, leading to increases in extensional and torsional stiffness. Torsional stiffness increased significantly under the tensile condition, and the ratio of filament stiffness under tensile force to that under no external force increased significantly on longer temporal scales. The results obtained from this study contribute to the understanding of mechano-chemical interactions concerning actin dynamics, showing that increased tensile force in the filament prevents actin regulatory proteins from binding to the filament. (C) 2011 Elsevier Ltd. All rights reserved.

【 授权许可】

Free