title: Probing the mechanical properties of magnetosome chains in living magnetotactic bacteria.
abstract: The mechanical properties of cytoskeletal networks are intimately involved in determining how forces and cellular processes are generated, directed, and transmitted in living cells. However, determining the mechanical properties of subcellular molecular complexes in vivo has proven to be difficult. Here, we combine in vivo measurements by optical microscopy, X-ray diffraction, and transmission electron microscopy with theoretical modeling to decipher the mechanical properties of the magnetosome chain system encountered in magnetotactic bacteria. We exploit the magnetic properties of the endogenous intracellular nanoparticles to apply a force on the filament-connector pair involved in the backbone formation and stabilization. We show that the magnetosome chain can be broken by the application of external field strength higher than 30 mT and suggest that this originates from the rupture of the magnetosome connector MamJ. In addition, we calculate that the biological determinants can withstand in vivo a force of 25 pN. This quantitative understanding provides insights for the design of functional materials such as actuators and sensors using cellular components.
authors.affiliation: Department of Biomaterials and ‡Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Körnig
authors.forename: Jiajia
authors.initials: J
authors.lastname: Dong
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bennet
authors.forename: Marc
authors.initials: M
authors.lastname: Widdrat
authors.forename: Janet
authors.initials: J
authors.lastname: Andert
authors.forename: Frank D
authors.initials: FD
authors.lastname: Müller
authors.forename: Dirk
authors.initials: D
authors.lastname: Schüler
authors.forename: Stefan
authors.initials: S
authors.lastname: Klumpp
authors.forename: Damien
authors.initials: D
authors.lastname: Faivre
mesh_terms: D055944:Magnetosomes / Q000737:chemistry* / Q000648:ultrastructure*; D042201:Magnetospirillum / Q000737:chemistry* / Q000648:ultrastructure*; D014961:X-Ray Diffraction / Q000379:methods