title: Zigzag motions of the myosin-coated beads actively sliding along actin filaments suspended between immobilized beads.
abstract: The motions of myosin filaments actively sliding along suspended actin filaments were studied. By manipulating a double-beam laser tweezers, single actin filaments were suspended between immobilized microbeads. When another beads coated with myosin filaments were dragged to suspended actin filaments, the beads instantly and unidirectionally slid along the actin filaments. The video image analysis showed that the beads slid at a velocity of ca. 3-5 microm/s accompanied with zigzag motions. When beads were densely coated with myosin filaments, the sliding motions became straight and smooth. The obtained results indicate that (1) during the sliding motions, the interaction between myosin heads and actin filaments is weak and susceptible to random thermal agitations, (2) the effects of thermal agitations to the sliding motions of myofilaments are readily suppressed by mechanical constraints imposed to the filaments, and (3) the active sliding force is produced almost in parallel to the filaments axis.
authors.affiliation: Biophysics Section, Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Japan.
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Wakayama
authors.forename: Makoto
authors.initials: M
authors.lastname: Shohara
authors.forename: Chiharu
authors.initials: C
authors.lastname: Yagi
authors.forename: Hanako
authors.initials: H
authors.lastname: Ono
authors.forename: Norihito
authors.initials: N
authors.lastname: Miyake
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kunioka
authors.forename: Takenori
authors.initials: T
authors.lastname: Yamada
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology*; D000199:Actins / Q000502:physiology*; D000818:Animals; D007834:Lasers; D008863:Microspheres; D009119:Muscle Contraction; D009218:Myosins / Q000502:physiology*; D011817:Rabbits; D014741:Video Recording
chemical_list: D000199:Actins; D009218:Myosins