Fig. 4.
Effects of CAS-1 on exchange of actin-bound nucleotides in the absence and presence of UNC-60B. ATP–G-actin (1 µM) was incubated with etheno–ATP in the presence of 0–0.5 µM MBP–CAS-1 (A,B), MBP–CAS-1N (C,D), or MBP–CAS-1C (E,F) without UNC-60B (A,C,E) or with 1 µM UNC-60B (B,D,F), and the fluorescence of etheno–ATP (arbitrary units) was monitored over time. (G) Rates of exchange of nucleotides (kobs) were determined from the data and plotted as a function of concentrations of the CAS-1 variants. Data are means ± s.d. of three independent experiments.