Figure 4. Schematic depiction of ALA-uptake and porphyrin biosynthesis pathways in Plasmodium-infected erythrocytes.
For simplicity, all membranes are depicted as single. Porphyrins synthesized in the infected erythrocyte cytoplasm from exogenous ALA may be transported across the parasite membrane via unspecified mechanisms or may be taken up via hemoglobin import mechanisms. SA inhibits ALAD and blocks porphyrin synthesis from ALA.
Figure 4—figure supplement 1. Growth of parasites in 1 µM 5-[13C4]-ALA results in detectable biosynthesis of 13C-labeled PPIX.
Parasites were grown overnight in 1 µM 5-[13C4]-ALA, permeabilized with saponin, extracted in DMSO, and analyzed by LC-MS/MS for 13C-labeled heme, PPIX, and CPP. Integrated peak areas measured for each analyze were normalized to that measured for the deuteroporphyrin internal standard added to each sample.