539185 Sigma-AldrichProteasome Inhibitor XX, GL5 - CAS 146304-91-8 - Calbiochem

This product has been discontinued.

A cell-permeable thienyl-oxathiazolone compound that effectively kills non-replicating Mycobacterium tuberculosis (~320- or 12,600-fold drop in BCG titre over 4 days by 50 µM GL5 with or without 50 µM DETA-NO, respectively) by selectively inhibiting its proteasome activity (by ~90% over 4 hours with 50 µM GL5) in a substrate-competitive and irreversible manner, while exhibiting little activity against trypsin, cathepsin B, MMP-2, or human 20S proteasome β1/2/5. GL5 displays no antibacterial activity against M. avium-intracellulare, Staphylococcus aureus, Salmonella enterica var. Typhimurium, or Pseudomonas aeruginosa. Although GL5 is known to reversibly inhibit α-chymotrypsin (K_i = 0.064 µM), it exerts no apparent toxicity to human or monkey cells. GL5 is reasonably stable in RPMI medium (t_1/2 = 110 mins at 37°C) albeit its moderate chemical reactivity toward glutathione (12.7% over 30 min at pH 7.0, RT; 10 µM GL5 and 25 µM GSH).