Recombinant Topoisomerase 2 Production Using Cultured Human Cell Lines

Recombinant human Topoisomerase 2 (TOP2) alpha and TOP2 beta proteins are valuable reagents for structural and biochemical analyses. Here, we describe a scalable method for production of high-purity recombinant TOP2 proteins using a HEK293F cell expression system with transient transfection of expression constructs. Human TOP2 is expressed as a fusion with YFP or mCherry, which serves dual purposes as an indicator of protein expression and an affinity tag that enables rapid isolation of TOP2 from cell lysates. Subsequent FPLC polishing of the protein yields milligram-scale yields of high purity and active recombinant TOP2.