Fig. 3. Auranofin disrupts the Zn(II)-dependent function of MCR-1.

a Inhibition of MCR-1 cleavage activity on NBD-glycerol-3-PEA by AuCl and Au(PEt₃)Cl. A representative image of TCL plate is shown here. b Membrane potential changes upon AUR treatment in MCR-1 positive and negative S. flexneri as determined by the ratios of green to red fluorescent signals. c Substitution of Zn(II) in Zn₃-MCR-1-S by Au(PEt₃)Cl over equilibrium dialysis. The metal content was determined by ICP-MS. d The metal contents upon supplementation of various amounts of Zn(II) into Au-MCR-1-S over equilibrium dialysis. The metal content was determined by ICP-MS. e Cellular thermal shift assays showing the binding of Au(I) to catalytic domain of MCR-1 in intact MCR-1-S-BL21 cells. MCR-1-S melting temperature was shifted from 61.7 to 58.1 °C for control and AUR-treated group, respectively. The images show the representative blottings of three independent experiments. f Structure of the active site of Au-MCR-1-S (PDB ID: 6LI6) with the anomalous density peak of Au ion shown as a purple sphere and anomalous density peak of Au in magenta mesh contoured at 5σ. b–e Data are presented as mean values ± SEM, n = 3 biologically independent samples. b P values were determined by an unpaired two-tailed student t-test with Welch’s correction. Source data are provided as a Source Data file.