Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion

Figure 4

Protocol for identifying and fitting reference and tethered Qdot images. Qdots bound to the NEM-myosin surface (reference) and tethered by full-length MyoVa in this example (tethered) (a) were located by thresholding the Qdot image channel and identifying continuous, round regions (b). The centers of these regions were used to locate 14 pixel square subimages (white squares in (c)). These subimages were then extracted (d) and fit with a two-dimensional Gaussian function (e) providing image size parameters:  nm and  nm.