Internal motility in stiffening actin-myosin networks.
We present a study on filamentous actin solutions containing heavy meromyosin subfragments of myosin II motor molecules. We focus on the viscoelastic phase behavior and internal dynamics of such networks during adenosine-triphosphate depletion. By combining microrheology and fluorescence microscopy, we observed a sol-gel transition accompanied by a sudden onset of directed filament motion. We interpret the sol-gel transition in terms of myosin II enzymology, and suggest a "zipping" mechanism to explain the filament motion in the vicinity of the sol-gel transition.
Uhde
Jörg
J
Physik Department, Technische Universität München, D-85747 Garching, Germany.
Keller
Manfred
M
Sackmann
Erich
E
Parmeggiani
Andrea
A
Frey
Erwin
E
D000199:Actins / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000737:chemistry*; D004548:Elasticity; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000648:ultrastructure; D009038:Motion; D046912:Multiprotein Complexes / Q000032:analysis / Q000737:chemistry / Q000648:ultrastructure; D015879:Myosin Subfragments / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D024462:Myosin Type II / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D011487:Protein Conformation; D012996:Solutions; D014783:Viscosity
D000199:Actins; D020409:Molecular Motor Proteins; D046912:Multiprotein Complexes; D015879:Myosin Subfragments; D012996:Solutions; D000255:Adenosine Triphosphate; D024462:Myosin Type II