Expression of Plasmodium falciparum ferredoxin-NADP+ reductase in Escherichia coli as a cleavable fusion with the SUMO protein

The ferredoxin-NADP+ reductase of Plasmodium falciparum (PfFNR) is an enzyme similar to that found in non-photosynthetic plastids of plants (1). It is involved in the biosynthesis of isoprenoid precursors (2) and it has been proposed as a target for novel antimalarial drugs (3). In order to support in-depth inhibition studies, large amounts of recombinant PfFNR are required. To this aim, we have developed an E. coli expression system based on the fusion with the yeast SUMO protein (pET SUMO system, Invitrogen). Recombinant PfFNR has been purified by two successive steps of immobilized nickel ion affinity chromatography. Mature PfFNR has been generated during the purification procedure by treatment with recombinant SUMO protease. Although the total yield of the procedure is lowered by the tendency of the fusion product to undergo spontaneous splitting in vivo, this quick and cheap isolation protocol can provide about 30 mg highly purified PfFNR from each run. 1. Balconi, E., et al. (2009) FEBS J. 276, 3825–3836 2. Röhrich, R.C., et al. (2005) FEBS Lett. 579, 6433–6438 3. Seeber, F., et al. (2005) Curr. Pharm. Des. 11, 3159–3172.