Figure 2.

The 450–1200 m/z range of the positive ion mass spectra obtained for 10 µM ALR peptide in 100 mM ammonium acetate buffer in the absence (A) in the presence (B) of 50 mM ZnCl₂, pH 7.3. Major signals at m/z 516.8, and 1032.5 correspond to the single and double charged molecular ion of the ALR peptide (marked as P). In the presence of zinc signal at 547.8 and 578.7 m/z were detected, which correspond to ALR complexes with one and two zinc ions. (C) Typical ITC titration curve (upper panel) and binding isotherm (lower panel) for zinc interactions with ALR peptide at 25 °C in 50 mM Tris buffer, pH 7.3.