This
assay represents a simplified model of muscle force and motion generation
(Warshaw et al., 1990; Warshaw, 1996). In this assay, myosin, a
molecular motor, is adhered to a nitrocellulose-coated microscope
coverslip. The coverslip is one surface of a 20 µl experimental
microchamber. Fluorescently labeled actin filaments in a solution
containing MgATP are perfused into the chamber and then the movement
of single actin filaments over the myosin surface is visualized
in an epifluorescence microscope equipped with an image intensified
video camera. Actin filament velocities can be determined by computer
(Work and Warshaw, 1992). The movie is a split screen image of actin
filaments moving over a surface of smooth (left) and skeletal (right)
muscle myosin. .
