Journal ArticleDOI
Tubulin: from atomistic structure to supramolecular mechanical properties
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The mesoscale model provides mechanical properties of the whole MT, thus allowing the comparison with data obtained by other previous experimental and theoretical studies, and provides a simple tool for the analysis of MT mechanical behaviour under different conditions.Abstract:
Microtubules (MTs) are fundamental structural elements in the cytoskeleton of eukaryotic cells. Their unique mechanical properties depend on the properties of the tubulin dimer, its interactions with surrounding dimers and the geometric organization within the MT. While the geometry has already been well described in experimental works, the mechanical characteristics of the dimer as well as of the individual monomers have up to date not been described. These may therefore provide new, additional insight to the microtubule tensile properties. In this paper we construct a mesoscale model of MT with a bottom-up approach. First, we evaluate the elastic constants of each of the two monomers together with the interaction force between them by means of molecular dynamics (MD) simulations carried out in an explicit water environment. Using the MD results, we model a 1 μm long MT as a cylinder constituted by interacting elastic elements and examine its properties via finite element method (FEM). The obtained results show an elastic constant value for α-tubulin of 11 N/m, while for the β-tubulin the elastic constant was measured to be 15.6 N/m. Concerning interactions between neighbouring monomers, the elastic constants along the protofilament (45 N/m for the intra-dimer interface and 18 N/m for the inter-dimer interface) are more rigid than elastic constants calculated for lateral interfaces (11 and 15 N/m). The mesoscale model provides mechanical properties of the whole MT, thus allowing the comparison with data obtained by other previous experimental and theoretical studies. We report here a Young modulus of 1.66 GPa for the MT under axial tension. In perspective our approach provides a simple tool for the analysis of MT mechanical behaviour under different conditions.read more
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Journal ArticleDOI
Anisotropic Elastic Network Modeling of Entire Microtubules
Marco Agostino Deriu,Monica Soncini,Mario Orsi,M. Patel,Jonathan W. Essex,Franco Maria Montevecchi,Alberto Redaelli +6 more
TL;DR: A multiscale approach was developed by merging the modeling contribution from MD and NMA to refine the molecular conformation and arrangement of the tubulin dimers inside the MT lattice and was able to simulate coarse-grain models of entire MTs, with lengths up to 350 nm.
Journal ArticleDOI
Multiscale modeling of cellular actin filaments: From atomistic molecular to coarse‐grained dynamics
Marco Agostino Deriu,Ardita Shkurti,Giulia Paciello,Tamara C. Bidone,Umberto Morbiducci,Elisa Ficarra,Alberto Audenino,Andrea Acquaviva +7 more
TL;DR: The proposed multiscale modeling approach allows to investigate the relationship between atomistic structure and changes on the overall dynamics and mechanics of the filament and can be easily extended to the characterization of other subcellular structures and used to investigation the cellular effects of molecular alterations due to pathological conditions.
Journal ArticleDOI
Computational model for the cell-mechanical response of the osteocyte cytoskeleton based on self-stabilizing tensegrity structures
TL;DR: A computational approach to model and simulate the cell structure of osteocytes based on self-stabilizing tensegrity structures is suggested and shows that the load acting on the nucleus is rising with increasing deformation applied to the integrins.
Journal ArticleDOI
A hydrophobic gold surface triggers misfolding and aggregation of the amyloidogenic Josephin domain in monomeric form, while leaving the oligomers unaffected.
Alessandra Apicella,Alessandra Apicella,Monica Soncini,Marco Agostino Deriu,Antonino Natalello,Marcella Bonanomi,David Dellasega,Paolo Tortora,Maria Elena Regonesi,Carlo Spartaco Casari,Carlo Spartaco Casari +10 more
TL;DR: It is demonstrated that the interaction with the gold surface triggers misfolding of the JD when it is in native-like configuration, while no structural modification is observed after the protein has undergone oligomerization, raising the possibility that biological membranes would be unable to affect amyloid oligomeric structures and toxicity.
Journal ArticleDOI
Molecular structural mechanics model for the mechanical properties of microtubules.
Jin Zhang,Chengyuan Wang +1 more
TL;DR: The SM model is found to be in good agreement with available simulation and experiment results, showing its robustness in studying the static deformation ofMTs and the potential for characterizing the buckling and vibration of MTs as well as the mechanical behaviour of intermediate and actin filaments.
References
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