Figure 3. Effect of copper on the digestion pattern of T. maritima CopA WT, ΔNMBD (NMBD entirely removed) and CXXC (double mutation of C17A and C20A in the NMBD) proteins.

Purified proteins (0.5 mg/ml) of CopA WT (a) and the mutants (b and c) were incubated with 0.5 mg/ml papain at 50°C in the presence of 1 mM BCS (copper chelator) (lanes 2–7) or with 10 μM CuCl₂ (lanes 8–13), as indicated at the bottom. The numbers on top of the gels refer to minutes of digestion: lane 1, 0 min; lanes 2 and 8, 2 min; lanes 3 and 9, 5 min; lanes 4 and 10, 10 min; lanes 5 and 11, 15 min; lanes 6 and 12, 20 min; and lanes 7 and 13, 30 min. The quenched samples were subjected to SDS electrophoresis. Reproduced from [34] © 2009 American Chemical Society.