Fig. 5.
Light gray bars: Normalized fluorescence response at 520 nm of 10 µM solutions of FlamS to addition of various metal ions in HEPES buffer (10 mM, pH 7.4) containing 40% (v/v) DMSO. Metal stock solutions were prepared in H2O from ferric ammonium citrate, FeCl2, NiCl2, ZnCl2, MnCl2, CdSO4, Hg(OAc)2, Pb(NO3)2, CoCl2 and AgNO3 and added to a final concentration of 20 µM, or 5 mM for CaCl2 and MgCl2. Dark gray bars: Fluorescence response after addition of 20 µM CuSO4 to the FlamS–Mn+ solutions. λex = 495 nm.