20S Immunoproteasome, human PBMC

Catalog number: SBB-PP0004, 25 μg

Highly active protein complex that has been purified from human peripheral blood mononuclear cell (PBMC) . Immunoproteasome is recognized as a strong drug target for autoimmune disease and cancer.  This immunoproteasome is supplied at >95% purity and experiments should be carried out at 20S immunoproteasome concentrations between 2-5 nM.   [1][2][3][4]

In stock


The immunoproteasome is structurally similar to constitutive 26S proteasome. The 20S core of immunoproteasome contains two outer rings composed of alpha subunits, and two internal 7-subunit containing rings each possessing 3 specific subunits responsible for proteasome catalytic activity.  In immunoproteasome these subunits (ß1, ß2, ß5) are replaced by three inducible subunits: PSMB9, PSMB10, and PSMB8, (ß1i, ß2i, ß5i).  These stress-induced subunits allow for the production of MHC-1 associating peptides, which are displayed as antigens on the cell surface.  These displayed peptides can then be recognized by immune surveillance CD8 T-Cells. 20S Immunoproteasome is recognized as a strong drug target for autoimmune disease and cancer.  This immunoproteasome is purified from human peripheral blood mononuclear cells and is supplied at >95% purity.  Cells used as starting material tested negative for hepatitis B surface antigen, antibodies to hepatitis C virus, HIV type 1 antigens, and antibodies to HIV type 1 and 2. Immunoproteasome is commonly associated with the 19S, PA28 α/ß, or the PA28γ regulatory complexes. If choosing to omit PA28 during use, 20S must be chemically activated by addition of 0.035%SDS in final assay buffers.

For Research Use Only, Not For Use In Humans.


Product Overview
Quantity: 25 μg
Molecular Weight: > 700 kDa
Purity: > 95% SDS-PAGE
Storage Buffer: 50 mM HEPES pH 7.5, 100 mM NaCl, 1 mM TCEP.
Storage Store at −80°C after product arrival. Avoid multiple freeze / thaws. It is recommended to make multiple aliquots after the first thaw.

Figures & Data

20S Immunoproteasome

Figure 1. 20S Immunoproteasome, SDS-PAGE.
From left to right, increasing amounts of 20S Immunoproteasome loaded onto a 4-20% SDS-PAGE gel, stained with coomassie brilliant blue.

Immunoproteasome Activity

Figure 2. 20S Immunoproteasome vs. 20S Constitutive Proteasome Activity.
20S Immunoproteasome is most active against LLVY-AMC (SBB-PS0010), PAL-AMC (SBB-PS0007), and ANW-AMC (SBB-PS0009) substrates, representing physiologically relevant chemotrypsin-like, β1i, and β5i immunoproteasome activity respectively.

Citations & References

1) Wang J, Maldonado MA (Aug 2006). “The ubiquitin-proteasome system and its role in inflammatory and autoimmune diseases”. Cellular & Molecular Immunology. 3 (4): 255–61. PMID 16978533.

2) Murata S, Sasaki K, Kishimoto T, Niwa S, Hayashi H, Takahama Y, Tanaka K (Jun 2007). “Regulation of CD8+ T cell development by thymus-specific proteasomes”. Science. 316 (5829): 1349–53. doi:10.1126/science.1141915. PMID 17540904.

3) Cascio P, Hilton C, Kisselev AF, Rock KL, Goldberg AL (May 2001). “26S proteasomes and immunoproteasomes produce mainly N-extended versions of an antigenic peptide”. The EMBO Journal. 20 (10): 2357–66. doi:10.1093/emboj/20.10.2357. PMC 125470free to read. PMID 11350924.

4) Mallery DL, McEwan WA, Bidgood SR, Towers GJ, Johnson CM, James LC (Nov 2010). “Antibodies mediate intracellular immunity through tripartite motif-containing 21 (TRIM21)”. Proceedings of the National Academy of Sciences of the United States of America. 107 (46): 19985–19990. doi:10.1073/pnas.1014074107. PMC 2993423free to read. PMID 21045130.