Ubiquitin Chains and Derivatives
Here at LifeSensors, we offer you products that help study this important system. You can find differently linked di-, tri- and tetraubiquitin chains for your studies. We also offer DUB-resistant polyubiquitin chains that help in investigation of binding interactions through pull-down studies and a control while determining potential deubiquitylase activity towards these chains. Our lysine to arginine mutants help in studying E1-E2-E3 mediated ubiquitin ligation and DUB linkage specificity. Our rhodamine or AMC attached ubiquitin helps you in determining the activity and specificity of ubiquitin hydrolases and screen for modulators of DUB activity. In addition to these traditional ubiquitin derivatives, we have developed unique ubiquitin-based tools for DUB characterization and drug discovery.
Deubiquitylases (DUBs) are enzymes that can hydrolyze ubiquitin chains. Recently, DUBs have become a promising target class for drug discovery in the ubiquitin-proteasome system. There is no “one-size-fits-all” assay for determining the activity of all DUBs. LifeSensors offers several efficient, plate-based DUB assays with a variety of readouts.
CHOP and CHOP2 assays:
These assays consists of ubiquitin fused to a reporter enzyme, as well as a substrate for the reporter enzyme. When fused to ubiquitin, the reporter is rendered catalytically inactive. Following cleavage of the Ub-reporter system by an active DUB, the free (and now active) reporter enzyme subsequently acts upon its fluorescence-based substrate to produce a fluorescent signal for real-time DUB activity readout.
Internally Quenched Fluorophore Diubiquitin (IQF-DiUb) assays:
LifeSensors’ IQF-DiUbs offer a variety of K48, K63 and K11-linked substrates with quencher-fluorophore pairs uniquely positioned on specific sites of the diubiquitin molecule, thus providing a highly efficient tool to measure selective activity of the DUB of interest.
Ub and UBL fluorophore assays:
The C-terminus of Ubiquitin/Ubls is conjugated via an isopeptide bond to a fluorogenic moiety. DUB-mediated fluorophore cleavage allows real-time monitoring of the DUB isopeptidase activity. Among the most common fluorogenic ubiquitin derivatives are Ub-Rhodamine and Ub-AMC.