PSMB11 belongs to the peptidase T1B family. It is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH . PSMB11 has an ATP-dependent proteolytic activity. Incorporated instead of PSMB5 or PSMB8, this unit reduces the chymotrypsin-like activity of the proteasome. It plays a pivotal role in development of CD8-positive T cells. The antibody is specific to PSMB11.