Selected compounds specifically target the mycobacterial proteasome pathway. (A) BCG proteasome is inactivated by selected compounds. Western blot of samples collected at time of maximal effect (refer to text and Figure 4A): DMSO, 6 day; Btz, 4 day; MTBC, 6 day; MTBA, 1 day; MTBB, 4 day. (B) Percent viability of BCG cells containing empty vector, BCG–pVV16, or BCG–pVV16-PA1 were treated with DETA-NO and either DMSO, Btz, or MTBA for 4 days.