Skip to main content
Log in

Mechanical and structural properties of in vitro neurofilament hydrogels

  • Original Paper
  • Published:
European Biophysics Journal Aims and scope Submit manuscript

Abstract

Neurofilaments belong to the class of cytoskeletal intermediate filaments and are the predominant structural elements in axons. They are composed of a semiflexible backbone and highly charged anionic sidearms protruding from the surface of the filaments. Here, the rheology of in-vitro networks of neurofilaments purified from pig spinal cord was determined. The mechanical properties of these networks are qualitatively similar to other hydrogels of semiflexible polymers. The low-deformation storage modulus G′(ω) showed a concentration (c) dependence of G′ ∼ c 1.3 that is consistent with a model for semiflexible networks, but was also observed for polyelectrolyte brushes. A terminal relaxation was not observed in the frequency range investigated (0.007–5 Hz), supporting the notion that sidearms act as cross-links hindering slip between filaments on a time scale of many minutes. The mesh size distribution of the network was measured by analysis of Brownian motion of embedded beads. The concentration dependence of the mesh size follows the same power law behaviour as found for F-actin networks, but shows a significantly wider distribution attributable to the smaller persistence length of neurofilaments. The attractive interaction between filaments is increased by addition of Al3+ ions resulting in a reduction of the linear response regime from strains bigger than 80% to less than 30%.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

  • Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002) Molecular biology of the cell, 4th edn. Garland Science, New York, p 924

    Google Scholar 

  • Aranda-Espinoza H, Carl P, Leterrier JF, Janmey PA, Discher DE (2002) Domain unfolding in neurofilament sidearms: effects of phosphorylation and ATP. FEBS Lett 531:397–401

    Article  Google Scholar 

  • Bathe M, Heussinger C, Claessens C, Bausch A, Frey E (2006) Mechanics of nanofiber bundles. q-bio.BM/0607040

  • Bausch AR, Kroy K (2006) A bottom-up approach to cell mechanics. Nat Phys 2:231–238

    Article  Google Scholar 

  • Chen JG, Nakata T, Zhang ZZ, Hirokawa N (2000) The C-terminal tail domain of neurofilament protein-H (NF-H) forms the crossbridges and regulates neurofilament bundle formation. J Cell Sci 113:3861–3869

    Google Scholar 

  • Claessens MMAE, Tharmann R, Kroy K, Bausch AR (2006) Microstructure and viscoelasticity of confined semiflexible polymer networks. Nat Phys 2:186–189

    Article  Google Scholar 

  • Dalhaimer P, Wagner O, Leterrier JF, Janmey PA, Aranda-Espinoza H, Discher D (2005) Flexibility transitions and looped adsorption of wormlike chains. J Poly Sci B 43:280–286

    Article  Google Scholar 

  • Gardel M, Shin J, MacKintosh F, Mahadevan L, Matsudaira P, Weitz D (2004) Elastic Behavior of cross-linked and bundled actin networks. Science 304:1301–1305

    Article  ADS  Google Scholar 

  • Gou JP, Gotow T, Janmey PA, Leterrier JF (1998) Regulation of neurofilament interactions in vitro by natural and synthetic polypeptides sharing Lys-Ser-Pro sequences with the heavy neurofilament subunit NF-H: Neurofilament crossbridging by antiparallel sidearm overlapping. Med Biol Eng Comput 36:371–387

    Article  Google Scholar 

  • Guzman C, Jeney S, Kreplak L, Kasas S, Kulik AJ, Aebi U, Forro L (2006) Exploring the mechanical properties of single vimentin intermediate filaments by atomic force microscopy. J Mol Biol 360:623–630

    Article  Google Scholar 

  • Head D, Levine A, MacKintosh F (2003) Distinct regimes of elastic response and deformation modes of cross-linked cytoskeletal and semiflexible polymer networks. Phys Rev E 68:061907

    Article  ADS  Google Scholar 

  • Hinner B, Tempel M, Sackmann E, Kroy K, Frey E (1998) Entanglement, elasticity, and viscous relaxation of actin solutions. Phys Rev Lett 81:2614–2617

    Article  ADS  Google Scholar 

  • Hohenadl M, Storz T, Kirpal H, Kroy K, Merkel R (1999) Desmin filaments studied by quasi-elastic light scattering. Biophys J 77:2199–2209

    Google Scholar 

  • Isambert H, Maggs A (1996) Dynamics and rheology of actin solutions. Macromolecules 29:1036–1040

    Article  Google Scholar 

  • Janmey PA, Leterrier JF, Herrmann H (2003) Assembly and structure of neurofilaments. Curr Opin Coll Int Sci 8:40–47

    Article  Google Scholar 

  • Kroy K, Frey E (1996) Force-extension relation and plateau modulus for wormlike chains. Phys Rev Lett 77:306–309

    Article  ADS  Google Scholar 

  • Kumar S, Hoh J (2004) Modulation of repulsive forces between neurofilaments by sidearm phosphorylation. Biochem Biophys Res Commun 324:489–496

    Article  Google Scholar 

  • Kumar S, Yin X, Trapp B, Hoh J, Paulaitis M (2002a) Relating interactions between neurofilaments to the structure of axonal neurofilament distributions through polymer brush models. Biophys J 82:2360–2372

    Article  Google Scholar 

  • Kumar S, Yin X, Trapp B, Paulaitis M, Hoh J (2002b) Role of long-range repulsive forces in organizing axonal neurofilament distributions: evidence from mice deficient in myelin-associated glycoprotein. J Neurosci Res 68:681–690

    Article  Google Scholar 

  • Langui D, Anderton BH, Brion JP, Ulrich J (1988) Effects of aluminum-chloride on cultured-cells from rat-brain hemispheres. Brain Res 438:67–76

    Article  Google Scholar 

  • Langui D, Probst A, Anderton B, Brion JP, Ulrich J (1990) Aluminum-induced tangles in cultured rat neurons—enhanced effect of aluminum by addition of maltol. Acta Neuropathol 80:649–655

    Article  Google Scholar 

  • Leterrier JF, Eyer J (1987) Properties of highly viscous gels formed by neurofilaments invitro—a possible consequence of a specific inter-filament cross-bridging. Biochem J 245:93–101

    Google Scholar 

  • Leterrier JF, Langui D, Probst A, Ulrich J (1992) A molecular mechanism for the induction of neurofilament bundling by aluminum ions. J Neurochem 58:2060–2070

    Article  Google Scholar 

  • Leterrier J, Kas J, Hartwig J, Vegners R, Janmey PA (1996) Mechanical effects of neurofilament cross-bridges—modulation by phosphorylation, lipids, and interactions with F-actin. J Biol Chem 271:15687–15694

    Article  Google Scholar 

  • MacKintosh F, Kas J, Janmey PA (1995) Elasticity of semiflexible biopolymer networks. Phys Rev Lett 75:4425–4428

    Article  ADS  Google Scholar 

  • Meechai N, Jamieson AM, Blackwell J, Carrino DA, Bansal R (2001) Nonlinear viscoelasticity of concentrated solutions of aggrecan aggregate. Biomacromolecules 2:780–787

    Article  Google Scholar 

  • Meechai N, Jamieson AM, Blackwell J, Carrino DA, Bansal R (2002) Viscoelastic properties of aggrecan aggregate solutions: dependence on aggrecan concentration and ionic strength. J Rheol 46:685–707

    Article  ADS  Google Scholar 

  • Mukhopadhyay R, Kumar S, Hoh JH (2004) Molecular mechanisms for organizing the neuronal cytoskeleton. BioEssays 26:1017–1025

    Article  Google Scholar 

  • Pampaloni F, Lattanzi G, Jonas A, Surrey T, Frey E, Florin EL (2006) Thermal fluctuations of grafted microtubules provide evidence of a length-dependent persistence length. Proc Natl Acad Sci USA 103:10248–10253

    Article  ADS  Google Scholar 

  • Rubinstein M, Colby R (2004) Polymer physics. Oxford University Press, Oxford

    Google Scholar 

  • Schilling J, Sackmann E, Bausch A (2004) Digital imaging processing for biophysical applications. Rev Sci Inst 75:2822–2827

    Article  ADS  Google Scholar 

  • Schmidt CF, Bärmann M, Isenberg G, Sackmann E (1989) Chain dynamics, mesh size and diffusive transport in networks of polymerized actin—a quasieleastic light scattering and microfluorescence study. Macromolecules 22:3638–3649

    Article  Google Scholar 

  • Semmrich C (2007) Nonlinear elasticity of pure F-actin solutions (in preparation)

  • Shea TB, Beermann ML (1994) Multiple interactions of aluminum with neurofilament subunits—regulation by phosphate-dependent interactions between C-terminal extensions of the high and middle molecular-weight subunits. J Neurosci Res 38:160–166

    Article  Google Scholar 

  • Tharmann R, Claessens MMAE, Bausch AR (2006) Micro- and macrorheological properties of actin networks effectively cross-linked by depletion forces. Biophys J 90:2622–2627

    Article  Google Scholar 

  • Tharmann R, Claessens MMAE, Bausch A (2007) Viscoelasticity of isotropically cross-linked actin networks. Phys Rev Lett 98:088103

    Article  ADS  Google Scholar 

  • Valentine M, Perlman ZE, Gardel ML, Shin JH, Matsudaira P, Mitchison TJ, Weitz DA (2004) Colloid surface chemistry critically affects multiple particle tracking measurements of biomaterials. Biophys J 86:4004–4014

    Article  Google Scholar 

  • Wilhelm J, Frey E (1996) Radial distribution function of semiflexible polymers. Phys Rev Lett 77:2581–2584

    Article  ADS  Google Scholar 

Download references

Acknowledgments

This work was supported by the DFG (SFB−413). The authors thank J.F. Letterier for helpful discussions. S.R. was supported by the CompInt program of the ENB Bayern.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. R. Bausch.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rammensee, S., Janmey, P.A. & Bausch, A.R. Mechanical and structural properties of in vitro neurofilament hydrogels. Eur Biophys J 36, 661–668 (2007). https://doi.org/10.1007/s00249-007-0141-7

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00249-007-0141-7

Keywords

Navigation