IQF DiUb Technology
LifeSensors’ diubiquitin substrates represent a new class of substrates for the continuous fluorescent measurement of true isopeptidase activity. The C-terminus of wild type ubiquitin is conjugated via an isopeptide bond to lysine 63 (K63) of a second ubiquitin molecule with the resultant diubiquitin forming an internally quenched fluorescent FRET pair (IQF). Each ubiquitin is labeled with a single molecule of either a fluorescent reporter (i.e. TAMRA) or a highly efficient quenching fluorophore. Cleavage of the IQF DiUb by deubiquitylases leads to separation of the fluorophore from quencher and subsequent increase in observed fluorescence.
IQF DiUb Variants
There is a remarkable difference between K48- and K63-linked ubiquitin molecules in their three-dimensional structure, which accounts for their individual functions. Beyond differential linkages (e.g. K48, K63, K11), LifeSensors has created subpanels of IQF diubiquitin substrates within each linkage. Because each DUB is likely to recognize and cleave substrates with unique steric considerations, these subpanels vary in location of reporter fluorophore and quencher. It is recommended that each DUB be empirically evaluated against a panel of IQF DiUb substrates to select the the optimal fluorophore/quencher pairing. In order to rapidly determine which of these fluorophore/quencher pairs are optimal for your DUB and/or determined likage specificity for your DUB, LifeSensors offers a panel of 6 substrates comprised of each K63-linked substrate available to date. Need bulk quantities? We would be happy to work out a custom price that fits your budget. Please contact us for more information. This product is protected by one or more US or Foreign patents, including US patent # 8,518,660. By purchasing this product, the purchaser agrees to comply with the terms of our Limited Use Label License.
|Molecular Weight||18,520.4 +/- 18 Da|
|Amount||Variable; but the equivalent of 25 µL at 20 µM of each substrate|
|Formulation||50 mM Sodium MES, pH 6.0|