The emergence of strains of Plasmodium falciparum resistant to the commonly used
antimalarials warrants the development of new
antimalarial agents. The discovery of
type II fatty acid synthase (FAS) in Plasmodium distinct from the FAS in its human host (type I FAS) opened up new avenues for the development of novel
antimalarials. The process of
fatty acid synthesis takes place by iterative elongation of butyryl-
acyl carrier protein (butyryl-ACP) by two
carbon units, with the successive action of four
enzymes constituting the elongation module of FAS until the desired acyl length is obtained. The study of the
fatty acid synthesis machinery of the parasite inside the red blood cell culture has always been a challenging task. Here, we report the in vitro reconstitution of the elongation module of the FAS of
malaria parasite involving all four
enzymes, FabB/F (
beta-ketoacyl-ACP synthase), FabG (
beta-ketoacyl-ACP reductase), FabZ (beta-ketoacyl-ACP
dehydratase), and FabI (enoyl-ACP
reductase), and its analysis by matrix-assisted
laser desorption-time of flight mass spectrometry (MALDI-TOF MS). That this in vitro systems approach completely mimics the in vivo machinery is confirmed by the distribution of acyl products. Using known inhibitors of the
enzymes of the elongation module,
cerulenin,
triclosan,
NAS-21/91, and (-)-
catechin gallate, we demonstrate that accumulation of intermediates resulting from the inhibition of any of the
enzymes can be unambiguously followed by MALDI-TOF MS. Thus, this work not only offers a powerful tool for easier and faster throughput screening of inhibitors but also allows for the study of the biochemical properties of the FAS pathway of the
malaria parasite.