title: Intermediate filaments in small configuration spaces.
abstract: Intermediate filaments play a key role in cell mechanics. Apart from their great importance from a biomedical point of view, they also act as a very suitable micrometer-sized model system for semiflexible polymers. We perform a statistical analysis of the thermal fluctuations of individual filaments confined in microchannels. The small channel width and the resulting deflections at the walls give rise to a reduction of the configuration space by about 2 orders of magnitude. This circumstance enables us to precisely measure the intrinsic persistence length of vimentin intermediate filaments and to show that they behave as ideal wormlike chains; we observe that small fluctuations in perpendicular planes decouple. Furthermore, the inclusion of results for confined actin filaments demonstrates that the Odijk confinement regime is valid over at least 1 order of magnitude in persistence length.
authors.affiliation: Institute for X-Ray Physics and Courant Research Centre Nano-Spectroscopy and X-Ray Imaging, Georg-August-Universität Göttingen, Göttingen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Nöding
authors.forename: Sarah
authors.initials: S
authors.lastname: Köster
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D007382:Intermediate Filaments / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D014746:Vimentin / Q000737:chemistry / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D014746:Vimentin