Filaments and Semiflexible Polymers

    Filaments are very thin rods, with a thickness in the nanometer regime, and can be bent by relatively small forces. The smallest bending forces arise from thermal collisions with the surrounding water molecules and lead to a scale-dependent bending stiffness [1]. When confined by surfaces or other filaments, bending fluctuations generate entropic forces that are repulsive and drive the filaments apart. [2] [3] Both in biological and in biomimetic systems, filaments can be assembled into a variety of spatial patterns such as filament bundles [4] or filament scaffolds [5]. When this assembly is mediated by molecular motors, the filaments undergo isotropic/nematic transitions as one varies the motor and/or the filament density [6].

    Filaments grow and shrink by attachment and detachment of monomers. [7] In the living cell, these processes are coupled to nucleotide hydrolysis, a two-step process consisting of ATP cleavage and phosphate release. In principle, both processes could be cooperative, i.e., could depend on the local neighborhood of the protomer in the filament [8]. Recent single filament experiments revealed, however, that phosphate release represents a random, non-cooperative process. [9].


  • A. Jégou, T. Niedermayer, J. Orbán, D. Didry, R. Lipowsky, M.-F. Carlier, and G. Romet-Lemonne
    Individual actin filaments in a microfluidic flow reveal the mechanism of ATP hydrolysis and give Insight into the properties of profilin.
    PLoS Biology 9, e1001161 (2011). PDF (512 KB)
    Supporting Information: PDF (1.8 MB)

  • J. Kierfeld, K. Baczynski, P. Gutjahr, T. Kühne, and R. Lipowsky
    Modelling semiflexible polymers: Shape analysis, buckling instabilities, and force generation.
    Soft Matter 6, 5764-5769 (2010). PDF (205 KB)

  • Kunkun Guo, J. C. Shillcock, and R. Lipowsky
    Treadmilling of actin filaments via Brownian dynamics simulations.
    J. Chem. Phys. 133, 155105 (2010). PDF (414 KB)

  • P. Gutjahr, R. Lipowsky, and J. Kierfeld
    Semiflexible polymer rings on topographically and chemically structured surfaces.
    Soft Matter 6, 5461-5475 (2010). PDF (377 KB)

  • Xin Li, R. Lipowsky, and J. Kierfeld
    Coupling of actin hydrolysis and polymerization: Reduced description with two nucleotide states.
    EPL 89, 38010 (2010). PDF (418 KB)

  • T. Kühne, R. Lipowsky, and J. Kierfeld
    Zipping mechanism for force generation by growing filament bundles.
    EPL 86, 68002 (2009). PDF (260 KB)

  • X. Li, J. Kierfeld, and R. Lipowsky
    Actin polymerization and depolymerization coupled to cooperative hydrolysis.
    Phys. Rev. Lett. 103, 048102 (2009). PDF (416 KB)
    EPAPS appendices: PDF (280 KB)

  • K. Guo, J. C. Shillcock, and R. Lipowsky
    Self-assembly of actin monomers into long filaments: Brownian dynamics simulations.
    J. Chem. Phys. 131, 015102 (2009). PDF (444 KB)

  • R. Chelakkot, R. Lipowsky and T. Gruhn
    Self-assembling networks and bundle structures in systems of filaments and crosslinkers - A Monte Carlo study.
    Soft Matter 5, 1504-1513 (2009). PDF (368 KB)
    Cover: PDF (888 KB)

  • J. Kierfeld, K. Frentzel, P. Kraikivski, and R. Lipowsky
    Active dynamics of filaments in motility assays.
    Eur. Phys. J. Special Topics 157, 123-133 (2008). PDF (672 KB)

  • K. Baczynski, R. Lipowsky, and J. Kierfeld
    Stretching of buckled filaments by thermal fluctuations.
    Phys. Rev. E 76, 061914 (2007). PDF (196 KB)

  • P. Gutjahr, R. Lipowsky and J. Kierfeld
    Persistence length of semiflexible polymers and bending rigidity renormalization
    Europhys. Lett. 76, 994 - 1000 (2006). PDF (264 KB)

  • J. Kierfeld, P. Gutjahr, T. Kühne, P. Kraikivski and R. Lipowsky
    Buckling, Bundling, and Pattern Formation: From Semi-Flexible Polymers to Assemblies of Interacting Filaments.
    J. Comput. Theor. Nanosci. 3, 1 - 14 (2006). PDF (544 KB)

  • J. Kierfeld, P. Kraikivski and R. Lipowsky
    Filament ordering and clustering by molecular motors in motility assays.
    Biophys. Rev. Lett. 1, 363 - 374 (2006). PDF (480 KB)

  • R. Chelakkot, R. Lipowsky and T. Gruhn
    Novel Low-Density Structure for Hard Rods with Adhesive End Groups.
    Macromolecules 39, 7138 - 7143 (2006). PDF (528 KB)

  • P. Kraikivski, R. Lipowsky and J. Kierfeld
    Enhanced ordering of interacting filaments by molecular motors.
    Phys. Rev. Lett. 96 , 258103 (2006). PDF (464 KB)
    Appendices: PDF (176 KB)

  • R. Lipowsky
    The Physics of Bio-Systems: From Molecules to Networks
    Biophys. Rev. Lett. 1, 223 - 230 (2006) PDF (1 MB)

  • P. Kraikivski, R. Lipowsky and J. Kierfeld
    Activated dynamics of semiflexible polymers on structured substrates.
    Eur. Phys. J. E 16, 319-340, (2005) . PDF (452 KB)

  • J. Kierfeld, T. Kühne and R. Lipowsky
    Discontinuous Unbinding Transitions of Filament Bundles.
    Phys. Rev. Lett. 95, 038102 (2005). PDF (202 KB)

  • P. Kraikivski, R. Lipowsky and J. Kiefeld
    Point force manipulation and activated dynamics of polymers adsorbed on structured substrates.
    Europhys. Lett. 71, 138 - 144 (2005). PDF (176 KB)

  • S. Klumpp, T.M. Nieuwenhuizen and R. Lipowsky
    Self-organized density patterns of molecular motors in arrays of cytosceletal filaments
    Biophys. J. 88, 3118-3132, (2005). PDF (236 KB)

  • J. Kierfeld and R. Lipowsky
    Duality mapping and unbinding transitions of semiflexible and directed polymers.
    J. Phys. A: Math. Gen., 38, L155-L161, (2005) . PDF (104 KB)

  • P. Kraikivski, R. Lipowsky and J. Kierfeld
    Barrier crossing of semiflexible polymers.
    Europhys. Lett. 66, 763-769, (2004) . PDF (164 KB)

  • J. Kierfeld, O. Niamploy, V. Sa-yakanit and R. Lipowsky
    Stretching of semiflexible polymers with elastic bonds.
    Eur. Phys. J. E 14, 17-34 (2004). PDF (404 KB)

  • J. Kierfeld and R. Lipowsky
    Unbundling and desorption of semiflexible polymers.
    Europhys. Lett. 62, 285-291 (2003). PDF (224 KB)

  • R. Bundschuh, M. Lässig, and R. Lipowsky.
    Semi-flexible polymers with attractive interactions.
    Eur. Phys. J. E. 3 , 295-306 (2000). PDF (252 KB)

  • R. Lipowsky
    Shape fluctuations and critical phenomena
    In H.~van Beijeren, editor, ''Fundamental Problems in Statistical Mechanics'', Vol. VII
    Elsevier Science Publishers (1990). PDF (996 KB)

  • R. Lipowsky.
    Renormalized interactions of interfaces, membranes, and polymers.
    Physica Scripta T29 , 259-264 (1989). PDF (352 KB)

  • R. Lipowsky.
    Parabolic renormalization group flow for interfaces and membranes.
    Phys. Rev. Lett. 62 , 704-706 (1989). PDF (280 KB)

  • R. Lipowsky and S. Leibler.
    Unbinding transitions of interacting membranes.
    Phys. Rev. Lett. 56 , 2541-2544 (1986). PDF (268 KB)