Fig. 2.

Absorbance spectrum of Ero1p-bound FAD. The spectrum of Ero1p was measured (black), CTAB was then added to release the bound FAD, and the spectrum was measured again (red). The original spectrum was corrected for the 1% dilution when adding the CTAB before the two spectra were superposed. The absorbance peak of the bound flavin is red-shifted from ≈448 nm to 454 nm, and a shoulder appears at ≈485 nm. Inset is an expansion of the absorbance scale in the visible region.