Fig. 4.

A SPR sensorgram corresponding to two consecutive injections of a 100 μM Hg²⁺ solution (apo-MT reconstitution) and a 100 μM Cd²⁺ solution (metal ion replacement). Glycine–HCl buffer was first injected to remove the metal ions in the MT molecules. Inset: upon metal release by the glycine–HCl treatment, the apo-MT was first reconstituted with Cd²⁺ by injecting 50 μM Cd²⁺. This was then followed by injecting 50 μM Hg²⁺ for the replacement study. Arrows indicate the times when injections were made.