title: Diffusion dynamics of motor-driven transport: gradient production and self-organization of surfaces.
abstract: The interaction between cytoskeletal filaments (e.g., actin filaments) and molecular motors (e.g., myosin) is the basis for many aspects of cell motility and organization of the cell interior. In the in vitro motility assay (IVMA), cytoskeletal filaments are observed while being propelled by molecular motors adsorbed to artificial surfaces (e.g., in studies of motor function). Here we integrate ideas that cytoskeletal filaments may be used as nanoscale templates in nanopatterning with a novel approach for the production of surface gradients of biomolecules and nanoscale topographical features. The production of such gradients is challenging but of increasing interest (e.g., in cell biology). First, we show that myosin-induced actin filament sliding in the IVMA can be approximately described as persistent random motion with a diffusion coefficient (D) given by a relationship analogous to the Einstein equation (D = kT/gamma). In this relationship, the thermal energy (kT) and the drag coefficient (gamma) are substituted by a parameter related to the free-energy transduction by actomyosin and the actomyosin dissociation rate constant, respectively. We then demonstrate how the persistent random motion of actin filaments can be exploited in conceptually novel methods for the production of actin filament density gradients of predictable shapes. Because of regularly spaced binding sites (e.g., lysines and cysteines) the actin filaments act as suitable nanoscale scaffolds for other biomolecules (tested for fibronectin) or nanoparticles. This forms the basis for secondary chemical and topographical gradients with implications for cell biological studies and biosensing.
authors.affiliation: School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar, Sweden.
authors.forename: Petr G
authors.initials: PG
authors.lastname: Vikhorev
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Vikhoreva
authors.forename: Mark
authors.initials: M
authors.lastname: Sundberg
authors.forename: Martina
authors.initials: M
authors.lastname: Balaz
authors.forename: Nuria
authors.initials: N
authors.lastname: Albet-Torres
authors.forename: Richard
authors.initials: R
authors.lastname: Bunk
authors.forename: Anders
authors.initials: A
authors.lastname: Kvennefors
authors.forename: Kenneth
authors.initials: K
authors.lastname: Liljesson
authors.forename: Ian A
authors.initials: IA
authors.lastname: Nicholls
authors.forename: Leif
authors.initials: L
authors.lastname: Nilsson
authors.forename: Pär
authors.initials: P
authors.lastname: Omling
authors.forename: Sven
authors.initials: S
authors.lastname: Tågerud
authors.forename: Lars
authors.initials: L
authors.lastname: Montelius
authors.forename: Alf
authors.initials: A
authors.lastname: Månsson
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D000199:Actins / Q000737:chemistry* / Q000378:metabolism; D000327:Adsorption; D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D004058:Diffusion; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008567:Membranes, Artificial; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D015879:Myosin Subfragments / Q000737:chemistry* / Q000378:metabolism; D010316:Particle Size; D011817:Rabbits; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000199:Actins; D005353:Fibronectins; D008567:Membranes, Artificial; D020409:Molecular Motor Proteins; D015879:Myosin Subfragments