Figure 4. Binding of Ag⁺ and bivalent metal ions by Cox17.

Mass spectra of Cox17 (1.4 μM) reconstituted with 4 equivalents of Ag⁺ (b), Zn²⁺ (c), Cd²⁺ (d) and Fe²⁺ ions (e) in 20 mM ammonium acetate (pH 7.6) and 0.3 mM DTT at 25 °C. Charge state +6 ions are presented and numbers on the peaks denote the metal stoichiometry of the complex.