Figure 2. The 3-Azioctanol inhibits ATP-induced luciferase activity.

Fresh American firefly luciferase pre-incubated with luciferin and increasing concentrations of the alkanol were rapidly mixed with ATP (see Results). A. Increasing concentrations of 3-azioctanol inhibited the initial phase of light emission. B. The slope of the linear portion of the initial peak of each curve was normalized (see Results) and plotted against the 3-azioctanol concentrations. Nonlinear least squares fitting yielded an IC₅₀ value of 220±47 µM and a Hill coefficient of 1.1±0.2.