In addition, MALDI-TOF MS has been used directly to
determine mechanisms of antibiotic resistance (Hrabak et al., 2011). Using proteomic techniques including C18 reverse-phase
liquid chromatography/MALDI mass spectrometry, Russo et al reported that plasmepsin V recognizes the PEXEL motif and cleaves
it at the correct site, which is essential for Plasmodium falciparum viability and endoplasmic reticulum residence is essential for its
function (Russo et al., 2010)