Scanning electron microscopy of the myosin-coated surface of polystyrene beads in a force-movement assay system for ATP-dependent actin-myosin sliding.
We examined the myosin-coated surface of polystyrene beads, which slide on actin filaments in the presence of ATP with characteristics essentially similar to those of contracting muscle, using a high-resolution scanning electron microscope (JSM-890, JEOL). The bead surface was mostly covered with myosin filaments (diameter, 15-45 nm) with helically arranged myosin heads. Considering the amount of force generated by the myosin heads on the bead (approximately 10 pN), this result indicates that the bead movement may be caused by about 10 myosin heads within a short myosin filament segment, but not by randomly oriented myosin heads.
Takahashi
I
I
Central Laboratory for Electron Microscopy, School of Medicine, Teikyo University, Tokyo, Japan.
Oiwa
K
K
Kawakami
T
T
Tanaka
H
H
Sugi
H
H
D000199:Actins / Q000502:physiology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology; D009218:Myosins / Q000502:physiology / Q000648:ultrastructure*; D011137:Polystyrenes; D011487:Protein Conformation; D011817:Rabbits; D013499:Surface Properties
D000199:Actins; D046911:Macromolecular Substances; D011137:Polystyrenes; D000255:Adenosine Triphosphate; D009218:Myosins