Processing of PfPP7 to PfPPJ in vivo and in vitro. Immunoblot analysis was performed with the antibodies PP7-1, -2 and -3 (Fig. 6) and anti-His tag antibody on the following samples: 1 = total protein (60 μg) from freshly isolated parasite; 2 = same as lane 1 except that the parasite was incubated at room temperature for 5 min; 3 = purified His-tagged recombinant PfPP7 (120 ng); 4 = as in lane 3 but after incubation with parasite extract; 5 = as in lane 4 except that the incubation mixture also contained protease inhibitor cocktail. The "Stain" panel analyzed reactions of the same lane numbers as above with higher amounts of protein (5 μg in lanes 3 and 4; 10 μg in lane 5); the gel was stained with Coomassie Blue. As indicated, the 112 kDa band is PfPP7 and the 38 kDa band approximates PfPPJ. The size markers are presented on the left and right. Details are given in Methods.