Figure 2.

Time course of actin filament elongation in the absence of profilin. (A) Shown here is kymography of the phase contrast images of beads at various G-actin concentrations. The single and double trap experiments shown at each condition were obtained from the same actin dumbbell. (B) Given here are time courses of the bead-to-bead distance. Gray and colored lines indicate traces from single- (∼0.13 pN) and double-trap experiments (3.5–5.5 pN), respectively. The average elongation rate (subunits/s) is shown. To see this figure in color, go online.