Biomechanics of actin filaments: A computational multi-level study

JOURNAL OF BIOMECHANICS

卷:44

Article

Deriu, Marco A.¹  Bidone, Tamara C.¹  Mastrangelo, Francesco¹  Di Benedetto, Giacomo¹  Soncini, Monica²  Montevecchi, Franco M.¹  Morbiducci, Umberto¹ 

[1] Politecn Torino, Dept Mech, Turin, Italy

[2] Politecn Milan, Dept Bioengn, Milan, Italy

关键词: Cytoskeleton;    Molecular dynamics;    Normal mode analysis;    Actin;    Biopolymer;    Coarse grain;    Elastic network;    Mechanics;    Biomechanics;    Elastic modulus;    Bending;    Stretching;    Stiffness;    Torsion;    Persistence length;    Fluctuations;    Mechanical properties;   

DOI  :  10.1016/j.jbiomech.2010.11.014

来源: Elsevier

【 摘 要 】

The actin microfilament (F-actin) is a structural and functional component of the cell cytoskeleton. Notwithstanding the primary role it plays for the mechanics of the cell, the mechanical behaviour of F-actin is still not totally explored. In particular, the relationship between the mechanics of F-actin and its molecular architecture is not completely understood. In this study, the mechanical properties of F-actin were related to the molecular topology of its building monomers (G-actin) by employing a computational multi-level approach. F-actins with lengths up to 500 nm were modelled and characterized, using a combination of equilibrium molecular dynamics (MD) simulations and normal mode analysis (NMA). MD simulations were performed to analyze the molecular rearrangements of G-actin in physiological conditions: NMA was applied to compute the macroscopic properties of F-actin from its vibrational modes of motion. Results from this multi-level approach showed that bending stiffness, bending modulus and persistence length are independent from the length of F-actin. On the contrary, the orientations and motions of selected groups of residues of G-actin play a primary role in determining the filament flexibility. In conclusion, this study (i) demonstrated that a combined computational approach of MD and NMA allows to investigate the biomechanics of F-actin taking into account the molecular topology of the filament (i.e., the molecular conformations of G-actin) and (ii) that this can be done using only crystallographic G-actin, without the need of introducing experimental parameters nor of reducing the number of residues. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

Free