FIGURE 7.
Tmod1 and Tmod3 similarly promote spontaneous platelet β/γcyto-actin polymerization. A and B, Tmod1 or Tmod3 was mixed with 3.4 μm platelet β/γcyto-G-actin (5% pyrene-labeled), and salts were added to initiate polymerization. Actin polymerization kinetics were monitored by increased pyrene-actin fluorescence as described under “Experimental Procedures.” AU, arbitrary units. In A, 300 nm Tmod3 was tested to allow direct comparison with 300 nm Tmod1 in a single experiment. C, concentration of β/γcyto-actin barbed (B) ends was calculated from the polymerization rate when 50% of monomers were polymerized and then normalized to the concentration of barbed ends in the “no Tmod” control. Data shown are mean ± S.D. (error bars) of three experiments.