Epigenetics
Table 1: Epigenetic enzyme classes/proteins for which vendors have developed screening assays, kits, reagents or tools Epigenetic Enzyme Classes/Proteins
Acetylation – histone acetyl transferases (HAT) Deacetylation – histone deacetylases (HDAC & Sirtuins) Histone Methylation – histone methyltransferases (HKMT & HRMT) DNA Methylation – DNA methyltransferases (DNMT) Demethylation – histone demethylases (HDM) Ubiquitination – ubiquitin ligases (E1, E2, and E3) Deubiquitination – deubiquitinases (DUB) Sumoylation – SUMO ligases Phosphorylation – kinases in relation to histones Dephosphorylation – phosphatases in relation to histones Binding Proteins (eg Bromo, Chromo & Tudor Domains etc) Offers Fee-For-Service Testing Against Epigenetic Targets 4 4
Active Motif 4 4 4 4 4 4 4 4 4
Biocius BioFocus BPS B 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
maintaining excellent data quality.
Substrates
require no special modifications (eg biotin, fluo- rophors or other tags). This means various biologi- cally relevant substrates may be used, including full nucleosomes, histone proteins or peptides. Since detection does not rely on antibodies, coupling enzymes or fluorescence, major causes of false pos- itives, false negatives and compound interference are eliminated. RB also offers fluorescence-based detection for all HDAC and Sirtuin isoforms with a variety of substrates. Histone Demethylase and deubiquitinase (DUBs) assays are also under devel- opment. Solving the puzzle of early stage discov- ery/development for emerging targets within the epigenetic field requires a comprehensive approach. One critical piece of the puzzle is the investment in a deep understanding of the biology of the target, and subsequent production of high quality recom- binant proteins for these challenging targets. Next, the development of relevant and powerful assay platforms allows for the sensitive detection of target activity and chemical inhibition. Access to high quality chemical compound libraries and screening expertise then allows for rapid hit identification and hit-to-lead development. The puzzle can then
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be further solved by the use of relevant cell-based assays for hit/lead validation. By embracing this multifaceted approach, RB has come to the fore- front of research service providers within the epige- netic drug discovery industry (Figure 22).
Discussion
At the time of the SBS session devoted to epigenet- ics2 it was easy to draw the conclusion that epige- netic screening was very much in its infancy, as only a few vendors appeared to be offering suitable screening tools and assays, and most of these were for HDAC & Sirtuins. This was also the feedback from HTStec’s survey last summer. However, put- ting together this review it is apparent that quite a lot has changed in the interim. In Table 1 the prod- uct offerings of the 12 companies discussed in this article are compared with respect to their support of screening assays, kits, reagents and tool provision for the epigenetic enzymes and proteins targets list- ed. What this table reveals it that the breadth of assays now covered extends well beyond the HDAC & Sirtuins, with some vendors supporting the entire list of targets. This would not have been achieved without the availability of more specific antibodies
Drug Discovery World Spring 2011
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