Proteasome subunit alpha type-3, also known as macropain subunit C8 and proteasome component C8, is a protein that in humans is encoded by the PSMA3 gene. The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the peptidase T1A family, that is a 20S core alpha subunit. Two alternative transcripts encoding different isoforms have been identified.

Differences in protocols and secondary/substrate sensitivity may require the PSMA3 antibody to be titrated for optimal performance.

Amino acids 88-127 (LADIAREEASNFRSNFGYNIPLKHLADRVAMYVHAYTLYS) from the human protein were used as the immunogen for the PSMA3 antibody.

After reconstitution, the PSMA3 antibody can be stored for up to one month at 4oC. For long-term, aliquot and store at -20oC. Avoid repeated freezing and thawing.