Fig. 1. Trp→D²G FRET.

RSO vesicles prepared from DW2 cells expressing WT MelB_Ec (upper panel) and WT MelB_St (lower panel) at a protein concentration of 1.0 mg/ml, or solubilized with 1% of an indicated detergent, were excited at 290 nm. Emission spectra were recorded between 430 and 550 nm in the absence of (black or curve 0) or presence of 10 μM D²G (red or curve 1), with successive addition of 20 mM NaCl (green or curve 2) and 120 mM melibiose (blue or curve 3). A.U., arbitrary unit.