Fig. 5.

DFP3 simultaneously binds the metal cofactors and exogenous ligands. UV/vis spectral changes upon addition of DTBC and DTBQ mixture, to generate DTBSQ^• in situ, to a solution of: di-Zn²⁺-DFP3 (A); di-Zn²⁺-ZnP-DFP3 (B). (C) Ferroxidase activity of apo-DFP3 at pH 7 (Hepes 50 mM, NaCl 100 mM). (D) Ferroxidase activity of ZnP-DFP3 at pH 7 (Hepes 50 mM, NaCl 100 mM). In C and D, the spectra display increase in the absorbance of the typical oxo-Fe³⁺ LMCT band near 360 nm. Inset: time course of the ferroxidase reaction followed at 360 nm.