FIG. 5.

Stannous chloride and auranofin inhibit ⁷⁵Se incorporation into T. denticola. (A and B) Actively growing cultures were treated with stannous chloride (12.5 and 50 μg/ml) or auranofin (1.7, 3.4, and 6.8 μg/ml), followed by the addition of ⁷⁵Se (sodium selenite) (A) or ³⁵S (methionine-cysteine mixture) (B). Cultures were harvested after 4 h at 37°C, and crude cell extracts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Radiolabeled proteins were visualized by using a phosphorimager (Molecular Dynamics). Identification of glycine reductase subunits (GrdA and GrdB, 18 and 45 kDa, respectively) is based upon predicted molecular masses (32).