Acting on actin: the electric motility assay.
We have developed a novel technique which allows one to direct the two dimensional motion of actin filaments on a myosin coated sheet using a weak electric field parallel to the plane of motion. The filament velocity can be increased or decreased, and even reversed, as a function of orientation and strength of the field. PMMA (poly(methylmethacrylate)) gratings, which act as rails for actin, allow one for the first time to explore three quadrants of the force velocity diagram. We discuss effective friction, duty ratio and stall force at different myosin densities. A discontinuity in the velocity force relationship suggests the existence of dynamical phase transition.
Laboratoire PhysicoChimie Curie (associé au-Centre National de la Recherche Scientifique (CNRS), Institut Curie, Paris, France.
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D
Riveline
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A
Ott
F
F
Jülicher
D A
DA
Winkelmann
O
O
Cardoso
J J
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Lacapère
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Magnúsdóttir
J L
JL
Viovy
L
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Gorre-Talini
J
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Prost
D000199:Actins / Q000737:chemistry* / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D001703:Biophysics; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D009068:Movement / Q000502:physiology; D009218:Myosins / Q000737:chemistry / Q000502:physiology; D019904:Polymethyl Methacrylate
D000199:Actins; D019904:Polymethyl Methacrylate; D009218:Myosins