Figure 7.

Zerumbone bound to tubulin and quenched the intrinsic tryptophan fluorescence in a concentration‐dependent manner. A, Tubulin (1 µmol/L) was incubated with zerumbone 0 (●), 5 (○), 10 (▼), 20 (∆), 40 (■) and 80 (□) µmol/L for 30 min at 37°C. The samples were then excited at 295 nm, and the emission spectrum was recorded. B, The change in the intrinsic tryptophan fluorescence intensity was plotted against different concentrations of zerumbone. Inset shows the double reciprocal plot, which yielded a Kd of 4 μmol/L