Mechanical measurements of single actomyosin motor force.
Biophys J
; 68(4 Suppl): 286S-289S; discussion 289S-290S, 1995 Apr.
Article
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| MEDLINE
| ID: mdl-7787092
ABSTRACT
To elucidate the mechanism of force generation by actomyosin motor, a measuring system was constructed, in which an in vitro motility assay was combined with an optical trapping technique. An actin filament of several micron long was attached to a gelsolin-coated polystyrene bead, and was allowed to interact with a small number (approximately 1/1 micron actin filament) of rabbit skeletal heavy meromyosin (an active subfragment of myosin) molecules bound to a nitrocellulose-coated coverglass. The bead position was determined at 33-ms intervals. We measured the force generation event at relatively low (100-400 nM) ATP concentration so that the occurrence of individual force generation events could be detected with our time resolution. The actin-bound bead held in the optical trap moved in a stepwise manner in the direction of the actin filament only in the presence of ATP. At the trap strength of 0.3 pN/nm, the maximum size of the step was 11 nm, and the maximum force associated with the movement was 3.3 pN.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Actomiosina
/
Contracción Muscular
Idioma:
En
Revista:
Biophys J
Año:
1995
Tipo del documento:
Article