Automated monitoring of phosphatidylcholine biosyntheses in Plasmodium falciparum by electrospray ionization mass spectrometry through stable isotope labeling experiments.

The metabolic pathways contributing to phosphatidylcholine biosyntheses in Plasmodium falciparum, the malaria-causing parasite, was explored by electrospray ionization mass spectrometry. Phosphatidylcholine produced by the CDP-choline pathway and by the methylation of phosphatidylethanolamine was identified and quantified through isotopic labeling experiments. A straightforward method based on cone voltage directed in-source fragmentations and relative abundance measurement of endogenous versus deuterated specific fragment ions was developed for simple and rapid automated data acquisition.

Unraveling the mode of action of the antimalarial choline analog G25 in Plasmodium falciparum and Saccharomyces cerevisiae.

Pharmacological studies have indicated that the choline analog G25 is a potent inhibitor of Plasmodium falciparum growth in vitro and in vivo. Although choline transport has been suggested to be the target of G25, the exact mode of action of this compound is not known. Here we show that, similar to its effects on P.