Nanomechanics of vimentin intermediate filament networks

Intermediate filaments are one of three classes of fibrous proteins in the cytoskeleton of eukaryotes, the others being actin filaments and microtubules. The dense filamentous networks and bundles provide important mechanical stability for the cell. Here we directly measure both the structure and mechanical properties of an in vitro model system for intermediate filaments reconstituted from purified vimentin protein at 1 mg mL−1. We show that the mesh size is on the order of 1 µm, a value that is preserved upon addition of divalent ions. These ions act as effective cross-linkers, further stiffening the network.

[1]  F. C. MacKintosh,et al.  Determining Microscopic Viscoelasticity in Flexible and Semiflexible Polymer Networks from Thermal Fluctuations , 1997 .

[2]  C. Broedersz,et al.  Origins of elasticity in intermediate filament networks. , 2010, Physical review letters.

[3]  Oliver Lieleg,et al.  Micro- and macrorheological properties of isotropically cross-linked actin networks. , 2008, Biophysical journal.

[4]  Christian Riekel,et al.  The mechanical properties of hydrated intermediate filaments: insights from hagfish slime threads. , 2003, Biophysical journal.

[5]  Jay X. Tang,et al.  Lamellar phase of stacked two-dimensional rafts of actin filaments. , 2003, Physical review letters.

[6]  D. Weitz,et al.  Elastic Behavior of Cross-Linked and Bundled Actin Networks , 2004, Science.

[7]  D A Weitz,et al.  Visualizing the strain field in semiflexible polymer networks: strain fluctuations and nonlinear rheology of F-actin gels. , 2007, Physical review letters.

[8]  Anna Whyatt,et al.  Notes and references , 1984, International Journal of Legal Information : Official Publication.

[9]  P. Janmey,et al.  Nonlinear elasticity in biological gels , 2004, Nature.

[10]  U. Aebi,et al.  Intermediate filaments: primary determinants of cell architecture and plasticity. , 2009, The Journal of clinical investigation.

[11]  W. Franke,et al.  Identification of a nonapeptide motif in the vimentin head domain involved in intermediate filament assembly. , 1992, Journal of molecular biology.

[12]  Sarika Sharma,et al.  Desmin and vimentin intermediate filament networks: their viscoelastic properties investigated by mechanical rheometry. , 2009, Journal of molecular biology.

[13]  C. Tanford.  Macromolecules , 1994, Nature.

[14]  Ueli Aebi,et al.  Intermediate filaments: molecular structure, assembly mechanism, and integration into functionally distinct intracellular Scaffolds. , 2003, Annual review of biochemistry.

[15]  F C MacKintosh,et al.  Distinct regimes of elastic response and deformation modes of cross-linked cytoskeletal and semiflexible polymer networks. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[16]  D. Reichman,et al.  Anomalous diffusion probes microstructure dynamics of entangled F-actin networks. , 2004, Physical review letters.

[17]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[18]  Christoph F. Schmidt,et al.  Chain dynamics, mesh size, and diffusive transport in networks of polymerized actin. A quasielastic light scattering and microfluorescence study , 1989 .

[19]  Mechanics of bundled semiflexible polymer networks. , 2006, Physical review letters.