Recombinant expression of PfPP1 in bacteria. The following proteins / extracts were analyzed by SDS-PAGE followed by staining with Coomassie Brilliant Blue R250: approximately 30 μg (protein) of total extract  of IPTG-induced E. coli BL21(DE3) containing the RIG plasmid and pET-15-PfPP1 (lane 2) or pET-15 without insert (lane 1); 4 μg of the purified recombinant (His)8-tagged PfPP1 (lane 3). Lane 4 shows an immunoblot in which 80 μg of 100,000 × g extract of Pf  was probed using a PP1 antibody described under Materials and Methods. Parasitic PfPP1 and the recombinant His-tagged PfPP1 bands are indicated by open and closed arrowheads, respectively. Protein markers (lane M) are indicated by Mr in thousands.