FIGURE 8.

Pyrene-excimer resulting from the copolymerization of pyrene-S265C Mg-actin and Bnr1 in F-salts. Panel A, 1 μm pyreneS265C Mg-actin was copolymerized with Bnr1 (line 1: no formin and line 2: 0. 5 μm) following induction of polymerization with MgCl₂ and KCl, and the fluorescence emission spectrum of this reaction was recorded from 375 to 600 nm using an excitation wavelength of 365 nm. Panel B, normalized net change in fluorescence intensity at 485 nm was plotted against the concentration of Bnr1 as described under “Experimental Procedures.” These experiments have been repeated twice with essentially same results, and the data presented here are the average of these two experiments.