Figure 2.

(A) Energy transfer between the tryptophan residue and bound bis-ANS in TF. The concentration of TF was 2 μM, and the bis-ANS concentrations were 0, 1, 2, 5, 10, 20, and 50 μM labeled as 1–7, respectively. The samples were excited at 295 nm, and emission spectra from 300 to 550 nm were recorded. (B) Concentration dependence of energy transfer between tryptophan and bound bis-ANS. The concentration of TF was 2 μM and the bis-ANS concentrations were 0, 1, 2, 5, 10, 20, and 50 μM. The samples were excited at 295 nm and emission was measured at 334 nm (○) and 490 nm (□).