FIG. 5.

(A) Native (nondenaturing) PAGE analysis of SOD activities of succinate-grown strain PAO1 and a clinical isolate that expresses the atypical MnSOD activity before (lanes 1 and 2, respectively) and after (lanes 3 and 4, respectively) the samples were subjected to a procedure that removes the metal from the active site of MnSOD. The procedure led to the expected loss of SOD activity in both strains. (B) Native (nondenaturing) PAGE analysis of SOD activity after Mn reloading. Lanes 1 and 3 , SOD activities of the samples from panel A, lanes 3 and 4, which were incubated with Mn in such a way as to reload the active site of the protein with Mn. Activity was restored with restitution of the migration pattern that existed prior to removal of metal and reloading. The migration of the atypical form of MnSOD of the clinical isolate was identical to that exhibited prior to the procedure (lane 2).