Topoisomerase II Drug Screening Kit

Topoisomerase II inhibitors have been shown to possess effective antibacterial, antiviral and anticancer activity. Identification of topo II inhibitors and antagonists requires tractable biochemical assays employing purified enzyme. The TopoGEN Drug Screening Kit contains the reagents necessary to screen for agents that affect enzymatic activity. To allow the customer maximum flexibility, purified topoisomerase II may be purchased separately from the kit (Prod. No. TOP-2000H).

This kit will allow detection of two kinds of topoisomerase inhibitors: those that stimulate formation of cleavable complexes and those that antagonize topoisomerase (topo) II action on the DNA. A known topo II poison is included as a control. The DNA substrate (pHOT1) included in this assay is ideal for these studies because it contains a single, high affinity topo II cleavage and recognition site. Topo II cuts pHOT1 primarily at a single site at the 54 bp of alternating purine/pyrimidine DNA (see Spitzner et al.,1990). Given that cleavage analyses require larger amounts of enzyme compared to catalytic assays, it is possible to conserve on enzyme by using a DNA substrate with a high affinity site. The assay system is based upon evaluating the formation of DNA cleavage products which may be nicked, open circular DNA or linear DNA. The products are then resolved by ethidium bromide gel electrophoresis as described in the kit.