Figure 2.

ATP-dependent phosphorylation of the PCB adduct of recombinant oat phytochrome is an intramolecular process. (A) Specific activity of AsphyA-ST autophosphorylation (dpm/μg AsphyA-ST; Pfr form) plotted versus μg AsphyA-ST analyzed. (B) A van’t Hoff plot of the same data obtained by plotting the logarithm of the initial rate (V_o) of AsphyA-ST phosphorylation, determined by converting the phosphorylation level (dpm) to pmol incorporation per minute, versus the logarithm of AsphyA-ST concentration (μg/ml). The slope of this line was 1.02 (r² = 0.994).