Biotinylated K33-Linked Tetra-Ubiquitin (Phosphorylated)

K33-linked ubiquitination is traditionally associated with regulation of the innate immune response. These chain types are also involved in protein stabilization and other non-degradative processes. It is a useful substrate for identifying and characterizing deubiquitinating enzymes that cleave the K33-linkage and for structural and binding studies of ubiquitin chain recognition by ubiquitin-associated domains (UBA) or ubiquitin-interacting motifs (UIMs). Phospho-ubiquitin chains represent a specialized class of polyubiquitin characterized by phosphorylation at Serine 65 and play a central role in mitophagy signaling pathways. K33 Tetra-Ubiquitin (phosphorylated) is a tetrameric chain of wild-type ubiquitin, wherein ubiquitin monomers are enzymatically linked together via an isopeptide bond between Lysine 33 and the C-terminal Glycine. The chains are then enzymatically phosphorylated at the Ser65 position. Once the K33 Tetra Ubiquitin has been formed and phosphorylated we then biotinylate it once on one available site on the ubiquitin chain. This biotin then acts as a means of detection via streptavidin or vidin. The applications are numerous from Western Blots to ELISAs. Testing can vary based off of intended application (EX: DUB activity/specificity).