title: Temperature control of the motility of actin filaments interacting with myosin molecules using an electrically conductive glass in the presence of direct current.
abstract: The motility of actin filaments interacting with heavy meromyosin molecules was directly observed on indium tin oxide-coated glass (ITO-glass), over which a surface current flowed. Because the increase in surface current applied to ITO-glass increases the temperature, we focused on the temperature-dependence of the sliding velocity and the effect of the current flow on the orientation of filament motion. Using high precision fluorescence measurements, the displacement vectors of filaments were collected at intervals of 1/30 s. The direction of filament motion was independent to that of current flow up to 0.17 A (7.7 A/m of surface current density); however, the velocity increased by approximately 2-fold when the surface temperature increased from 25 °C to 37 °C. The moving actin filaments exhibited a broader velocity distribution at high temperature than at low temperature. Collectively, these data suggest that using ITO-glass with a surface current to generate a well-controlled temperature change may serve to evaluate temperature-dependent transient responses in protein activity under a microscope, without interference from electrical effects.
authors.affiliation: Department of Biomedical Information Engineering, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
authors.forename: Reito
authors.initials: R
authors.lastname: Wada
authors.affiliation: Department of Biomedical Information Engineering, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.affiliation: Department of Biomedical Information Engineering, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Bio-Systems Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa 992-8510, Japan. Electronic address: khatori@yz.yamagata-u.ac.jp.
authors.forename: Kuniyuki
authors.initials: K
authors.lastname: Hatori
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D055592:Biophysical Phenomena; D004553:Electric Conductivity; D005898:Glass; D066298:In Vitro Techniques; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000378:metabolism; D009038:Motion; D015879:Myosin Subfragments / Q000737:chemistry* / Q000378:metabolism; D011817:Rabbits; D013696:Temperature; D017971:Tin Compounds
chemical_list: D020409:Molecular Motor Proteins; D015879:Myosin Subfragments; D017971:Tin Compounds; C109984:indium tin oxide
keywords: Indium tin oxide; Motility assay; Motor protein; Temperature dependence; Velocity distribution