Bortezomib is a reversible inhibitor of the chymotrypsin-like
activity of the 26S proteasome in mammalian cells. The 26S
proteasome is a large protein complex that degrades
ubiquitinated (cyclins, tumor suppressors, BCL-2, and cyclindependent kinase inhibitors) proteins & inhibition of these
degradations, sensitizes the cells to apoptosis. Bortezomib is
a potent inhibitor of 26S proteasome.