No drugs directly targeting E3 ligases or DUBs have been developed by traditional methods thus far. Celgene repurposed Thalidomide for multiple myeloma treatment in 2008. Cereblon, a ubiquitin E3 ligase subunit, was identified as the molecular target of Thalidomide in 2012. Despite the obvious potential of the ubiquitin pathway to furnish novel drug targets, it has become clear that traditional approaches to drug discovery are not effective for targeting ubiquitin pathway enzymes. Due to their unique mechanisms of action and considerable conservation within enzyme families, ubiquitin ligases and DUBs are often considered undruggable. LifeSensors is developing revolutionary approaches to ubiquitin based drug discovery. Let LifeSensors help you in your drug discovery efforts!
High Throughput Validation and Biomarkers: LifeSensors has developed a suite of assays for validation of ubiquitin pathway drugs in cultured cells and model organisms. Ligase and DUB inhibitors both cause downstream changes on the ubiquitylation state of their protein substrates. The biological consequences of altered ubiquitylation determine the effectiveness of drug treatment. Thus, protein ubquitylation serves as a biomarker for the activity of DUB and ligase drugs. LifeSensors has pioneered biomarker methodology (UbiTest) that will help you identify in vivo ligase substrates and biomarkers. We have further adapted our TUBE technologies to enable high-throughput assays for cellular substrate ubiquitylation. These biomarker assays enable researchers to distinguish promising lead compounds from off-target compounds. In ligase and DUB drug discovery, connecting the dots is the most important step. Developing structure activity relationships from purified enzymes, to cultured cells, to animal models is key to success in ligase and DUB drug discovery. LifeSensors’ suite of assays and in vivo biomarker technologies can help establish rank order potency, the most important step that helps medicinal chemists optimize novel and potent compounds. We invite you to discuss your drug discovery validation needs with our senior management.
DUBs Drug Discovery and HTS: Many labs use ubiquitin-AMC or ubiquitin rhodamine as substrates for assaying DUB activity. In nature DUBs work by removing the ubiquitin moiety from proteins or cleaving poly-ubiquitin chains in a selective manner. AMC and rhodamine are small adducts attached to the C-terminus of ubiquitin that fluoresce upon cleavage by DUBs. Small molecules attached to the C-terminus are not physiological substrates for all the DUBs, especially USPs. In addition, these substrates don’t provide selectivity and structural alterations induced by cleaving a physiological substrate thus companies and labs fail to discover good hits during HTS. Profiling compounds that hit certain DUBs by using artificial substrates also misleading. Some ubiquitin and Epigenetic companies offer these services for selectivity panel or monitoring inhibition by compounds using these assays. We believe such results are misleading and don’t provide the accurate properties of the compounds. LifeSensors has developed ~30 different assays for DUBs. Most of the assays utilize physiological substrates, poly-ubiquitin isopeptide chain selective substrates, and a number of proteins attached to the C-terminus of ubiquitin that report a flourgenic signal upon cleavage by DUBs. These substrates make up a large suite of assay technologies available to our customers. No other company provides such a wide variety of tools for HTS and physiological assays for characterizing compounds and establishing a selectivity panel. LifeSensors has expressed, purified, and characterized ~35 DUBs for HTS and compound profiling. LifeSensors has in house collections of DUB-centric compound libraries that act as standards for monitoring the inhibition of your compound or characterizing your DUB. LifeSensors has developed systems that allow in vivo monitoring of DUB substrates. We invite you to discuss your DUB screening needs with our senior management.
E3 Ligase Drug Discovery and HTS: E3 ligases remain among the most difficult enzymatic targets to assay and screen. E3 ligases are dependent on upstream E1 and E2 enzymes for the activation of ubiquitin, which they then transfer to protein substrates. As a result, catalytic assays for E3 ligases are complex and prone to off-target false positives. LifeSensors has developed 15 suites of assays encompassing both traditional and non-traditional approaches for identifying selective ligase drugs. LifeSensors’ small molecule library contains a collection of ligase-centric compounds which can act as a gold standard for your ligase drug discovery efforts. Furthermore, LifeSensors has the tools to quickly exclude off-target hits through a variety of complementary biochemical and biophysical validation assays. In E3 ligase drug discovery, connecting the dots is particularly important. Quickly distinguishing true hits from false positives, developing structure-activity relationships, and establishing rank order potency from purified enzymes to in vivo models are key steps to success. LifeSensors brings together the tools and expertise necessary to overcome the many pitfalls in the E3 ligase field. We invite you to discuss your E3 ligase screening needs with our senior management.