Purity: > 90% by SDS - PAGE Format: Liquid. 20mM Tris-HCl buffer (pH8.0) containing 10% glycerol. PSME1 is an interferon gamma (IFNG) inducible proteasome activator required for presentation of certain major histocompatibility (MHC) class I antigens. The PSME1 complex is an alternative proteasome activator that does not employ the use of ubiquitin. The PSME1 complex is composed of two homologous subunits, alpha and beta, which have similar catalytic properties and associate to form a hexameric ring. Recombinant human PSME1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.