Fluorescence polarisation assay reagent based on a 5-carboxytetramethylrhodamine (TAMRA) modified Lys-Gly sequence linked to ubiquitin via a native isopeptide bond with the lysine side-chain. Has utility as a deubiquitinating enzyme (DUB) substrate for high sensitivity continuous output at longer wavelengths than traditional fluorophores helping to overcome problems of compound auto-fluorescence or quenching in screening assays. Cleavage of isopeptide bond more closely represents the
