FIGURE 9.

Mechanical activation from LP state. A, schematic image of manipulation with magnetic tweezers. A magnetic bead was attached onto the rotor as a handle for manipulation and as a rotation marker. Experiments were carried out at 4 mm ATP. B, typical time courses of the mechanical activation, a failed case (top) and a successful case (bottom). After ensuring that the molecule entered into the LP state by waiting more than 5 min, the manipulation was conducted with magnetic tweezers. In these cases, V₁ in the LP state was forcibly rotated in the direction of rotation by +100° (top) and +120° (bottom). The green regions of the expanded time courses represent the time under manipulation. Symbols on the x axis and trajectories indicate the continuity of LP state until 400 s. C, probabilities of activation after manipulation at 4 mm ATP (blue) and at 4 mm ATP and 200 μm ADP (red).