Figure 5. Effect of tropomyosin on SKMM-II-driven actin filament gliding in relation to myosin concentration.
The working concentration of SKMM-II employed in our actin filament gliding assays (Figure 4B; Table I) was 5 nM (2.5 µg/ml). We also compared the motility activity of SKMM-II at higher myosin concentrations. A) The effect of saturating SKMM-II (50 nM/25.0 µg/ml) was tested with bare actin filaments versus Cdc8p-, Tpm3.1cy-, or Tpm4.2cy-decorated filaments. The histogram summarizes the SKMM-II filament gliding rates (n=30–70 filaments per experiment). B) Histogram summarizing SKMM-II gliding efficiency versus myosin concentration with bare actin filaments versus Cdc8p-decorated filaments. Gliding efficiency reflects the number of motile (myosin-driven) actin filaments/total actin filaments. A total of 2–5 different movie fields were scored. The relative number of motile filaments scored for actin alone at 2.5 µg/ml was set to 1.0.