Anti-Ubiquitin, HRP-Conjugated (MAb; clone VU-1)

LifeSensors has developed several monoclonal antibodies that recognize polyubiquitylated proteins and free ubiquitin. VU-1 recognizes all ubiquitin linkages (mono, K6, K11, K27, K29, K33, K48, K63, and linear) and now we have conjugated VU-1 to HRP so western blotting is performed in a single step (no secondary antibody required). Ubiquitin (Ub), a highly conserved, 8 kDa polypeptide present in all eukaryotic cells, is conjugated to the e-amino group of lysine residues in the target protein through the sequential action of three enzymes, an E1 Ub activating enzyme, an E2 conjugating enzyme, and an E3 ligase. In addition, the seven lysines within Ub itself can serve as Ub acceptors leading to the formation of polyubiquitin chains. Among these, K48 and K63 linkages are well characterized; K48-linked polyubiquitylation targets proteins for proteasome degradation whereas K63 linkages regulate signaling events, receptor endocytosis and immune responses. Polyubiquitin linkages at other lysines are less prominent and their physiological roles are under investigation.