Biotin-ANP-Ub-PA (UbiQ-077)
DUB activity-based probe with UV cleavable biotin tag

UbiQ-077 is an activity-based probe for deubiquitinating enzymes (DUBs), in which the N-terminal biotin tag is linked to the Ub protein through a UV cleavable linker (ANP= 3-amino-3-(2-nitrophenyl)propanoic acid, Figure 1). UbiQ-077 allows one to use the powerful biotin affinity tag but also to release any covalently bound Ub-DUB complexes under milder (photolysis) conditions. Note that the propargylamide (PA) electrophile forms an acid labile bond with the active site cysteine of a DUB (Fig 2), allowing deconjugation of the Ub-DUB complex if required.

Figure 1.

(1) Aoki et al. Bioorg Med Chem 2009, 17, 3405.
(2) Rodenko et al. Nat Prot 2006, 1, 1120.