TR-FRET E3 ASSAY


The TR-FRET E3 assay involves terbium-labeled TUBEs that bind to polyubiquitin chains synthesized by the target E3 ligase. Terbium and fluorescein are a FRET pair, so polyubiquitin chains containing fluorescein-labeled ubiquitin yield a FRET signal when bound by a terbium-TUBE. This signal can be monitored over time in a homogenous, high-throughput format, making it ideal for small-molecule screening.