Figure 19.

Fluorescence polarization measurements of kinesin rocking motion when bound to a microtubule. (b) Microtubules decorated with many fluorescently labeled kinesin fragments exhibit fluorescence anisotropy when kinesin is bound to AMP, but not when bound to ADP. (c) Single-molecule measurements show fluorescence anisotropy of AMP-bound kinesin taken at four different polarization angles. These measurements can be translated into immobility factors, showing that AMP-bound kinesin molecules are held rigid, while ADP-bound kinesin has high rotational mobility. Adapted from ref (243).