Fig. 3.

Kinetics of cAMP accumulation by the purified IlaC proteins in the dark and light. (Upper row) First-generation light-responsive proteins: IlaC18, light-inactivated AC; IlaC17, 22 and 25, light-activated AC. (Lower row) IlaC22 mutants with improved photodynamic ranges: IlaC22 R509W and IlaC k27. AC activity was measured at room temperature. cAMP was quantified by high-performance liquid chromatography (HPLC). Black traces, dark (dim green light); red traces, irradiation with 700-nm light.