title: Mechanical splitting of microtubules into protofilament bundles by surface-bound kinesin-1.
abstract: The fundamental biophysics of gliding microtubule (MT) motility by surface-tethered kinesin-1 motor proteins has been widely studied, as well as applied to capture and transport analytes in bioanalytical microdevices. In these systems, phenomena such as molecular wear and fracture into shorter MTs have been reported due the mechanical forces applied on the MT during transport. In the present work, we show that MTs can be split longitudinally into protofilament bundles (PFBs) by the work performed by surface-bound kinesin motors. We examine the properties of these PFBs using several techniques (e.g., fluorescence microscopy, SEM, AFM), and show that the PFBs continue to be mobile on the surface and display very high curvature compared to MT. Further, higher surface density of kinesin motors and shorter kinesin-surface tethers promote PFB formation, whereas modifying MT with GMPCPP or higher paclitaxel concentrations did not affect PFB formation.
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, PO Box 5800, MS 1303, Albuquerque, NM, 87185, USA.
authors.forename: Virginia
authors.initials: V
authors.lastname: VanDelinder
authors.affiliation: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Adams
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, PO Box 5800, MS 1303, Albuquerque, NM, 87185, USA.
authors.forename: George D
authors.initials: GD
authors.lastname: Bachand
mesh_terms: D000818:Animals; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004330:Drosophila / Q000187:drug effects / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism; D016547:Kinesins / Q000378:metabolism*; D055595:Mechanical Phenomena / Q000187:drug effects; D008856:Microscopy, Fluorescence / Q000379:methods; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D017239:Paclitaxel / Q000494:pharmacology; D011485:Protein Binding / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D016547:Kinesins; D017239:Paclitaxel