Fig. 2
Crystal structure of HuFtMt (A1), ΔC (A2), 2Cys-ΔC (A3), and 3Cys-ΔC (A4) treated with HAuCl4, respectively. Au ions are highlighted in orange. B1 Highlighting two gold ion (yellow) coordination sites where Cys102 and Cys130 are involved. B2 No Au ion binding was observed at the location of Ala102 and Ala130 in mutant ΔC. B3 Highlighting one Au ion (yellow) binding site at the modified ferroxidase center of 2Cys-ΔC from two different views (side-view, left; top-view, right). B4 Highlighting two Au ion (yellow) binding sites and involved amino acid residues at the modified ferroxidase center of 3Cys-ΔC. Fluorescent and UV–vis absorption spectra of HuFtMt (C1), ΔC (C2), 2Cys-ΔC (C3), and 3Cys-ΔC (C4) treated with HAuCl4 at basic condition, respectively. Inset shows two photo of the mixture under daylight (left) and UV-light (right)